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Gallery, Projects and General => Project Logs => Topic started by: vtsteam on March 09, 2015, 01:12:32 PM

Title: Building a New Lathe
Post by: vtsteam on March 09, 2015, 01:12:32 PM
I keep thinking I wish I had a new lathe. I have the Gingery lathe that fits in my tiny shop, but it lacks screw cutting capability, and has design limited stifness.

And I have the Craftsman 12" x 36" (5' overall length) lathe that doesn't fit in the tiny shop, does have a complete set of change gears.

I'd really like something somewhere between the two -- a benchtop lathe that had say 9" by 18" capacity, to fit in the tiny shop and one which would have easy quick change screw cutting.

I don't know whether to sell the Craftsman and buy one of the Asian lathes, or think about building a new lathe. I've even considered shortening the Craftsman bed 18" so it will fit in the small shop. (I know that's a travesty!) and adding a stepper on the leadscrew for NC thread cutting.

Then there's the used lathe market. But almost nothing in used machinery is local within 200 miles, and I don't want to deal with renovation of hidden problems at this point. If it was known good to go, and I could see it and try it, and I could afford it, I suppose. But I don't want a several month lathe rebuild project. I want to build engines on a lathe.

Well, I wouldn't mind building a new lathe from scratch as a project, that could be interesting, but otherwise, I guess ideally, if tomorrow I could just sell some machinery  (lathe and Atlas horizontal mill) and get a well suited new lathe for what I want, I'd probably go for it.

I don't know how stiff those Sieg 9x20's are compared to the Craftsman. I did notice that a lot of the travel specs for things like cross slide, and tailstock are less, and the chuck looks pretty small by comparison. I don't want a less stiff machine -- I'd say the Craftsman is minimal, as is. I've had it tuck under when parting twice

Any suggestions, thoughts?
Title: Re: Building a New Lathe
Post by: bertie_bassett on March 09, 2015, 01:33:11 PM
if time scale isn't important and you want another project, id say build one

either up scale the gingery lathe, or copy a design that's the right size. a boxford or denford sounds like the size you want.
 the denford website has pd'sf with almost all the component details ( gears, shafts etc) which could be used as a reference.?

not sure how youd go about making the bed, but perhaps linear rails could be used?
Title: Re: Building a New Lathe
Post by: RobWilson on March 09, 2015, 01:42:02 PM
BUGGER !!!  :palm:

Dam shame there is a dirty great ocean between us Steve , I have a lathe going spare a Boxford AUD  , I would have done a trade for the we HZ mill .


Rob

Title: Re: Building a New Lathe
Post by: vtsteam on March 09, 2015, 09:41:49 PM
Ah well Rob, I think that would have been a happy trade -- the mill is in great shape and lots of new tooling to go with it, and I've admired the Boxfords.

I see Grizzly has the 9" x 19"  G4000 on sale for $1000 or so delivered -- that's 9" x 19"  which would probably fit the requirements. And has the QC gearbox. But never having seen or used one, I have no idea how much I'd like it.

http://www.grizzly.com/products/9-x-19-Bench-Lathe/G4000

Any G4000 owners out there?

Bertie, It is intriguing to think about building one. I would probably want do my own design rather than an enlarged Gingery, and I Imagine a lot of fabricated rather than cast parts this time around.

But certainly everything I've learned I liked about my first lathe (and the Craftsman, too) would go into it. Plus some other things. I'm not worried about the bed at all. I've got all kinds of heavy steel shapes here, Including rails from a auto lift, and anything I decide to use is likely to be heavier and stiffer than what I have now in the little aluminum castings topped with a 1/4" x 3" cold rolled slab ways of the Gingery.

I used a machined 4 foot carpenter's level to hand scrape the Gingery. But now I have a real cast iron straight edge, and surface plate I bought at an auction about 8 years ago, and unused since..

I don't think I'd mess with change gears or a gearbox at all, and handle screw cutting electronically, and the same for speed control.  I don't know if I'd go full CNC, probably not, or at least not right way. This is still a small benchtop lathe  for the tiny shop, and I still enjoying turning cranks. But for screw cutting you don't turn cranks anyway, and it would be nice to just set it and go.

I dunno. That Grizzzly is tempting, and I think I could sell enough stuff to pay for it. It would be nice to just start turning right away.
Title: Re: Building a New Lathe
Post by: Brass_Machine on March 10, 2015, 12:27:16 AM
I dunno Steve. I have heard better things about the 10x22 Lathe (http://grizzly.com/products/10-x-22-Bench-Top-Metal-Lathe/G0602). I think if I was in the position to buy a new lathe, that would be the one I would get.

Eric
Title: Re: Building a New Lathe
Post by: John Rudd on March 10, 2015, 03:29:03 AM

Any G4000 owners out there?


Yup I have the Chester equivalent the 9*20.....Great machine for the size....Modded mine by fitting a 3 ph motor and vfd.... :zap:
Title: Re: Building a New Lathe
Post by: PekkaNF on March 10, 2015, 04:12:49 AM
Ouch. Lathe blues...I have three lathes now and 1-3 of them has to go. I wish I could replace least two of them with Boxford AUD size lathe, but I really need proper metric machine. I don't care changing belt and such to change the speed, but to change gears and mess with feeds/screw cutting is getting into me.

I almost bought AUD from UK. Even after shipping that might be an option. Once in 1-2 years comes really nice Weiler or something like that on the market, but it gets snatched in nanoseconds. I have decided to save a little money and act fast when next one comes in couple of years.

Good new ones are expensive and they are not made in china. If you buy old or chinese you buy a project, it is just a fact of life. Ergometricly old western stuff seems to be better in every aspect. I have one chinese lathe and it is very hard to see at first anything wrong with it, but every control in apron is shaky, you can't get main slide close enough of the spindle if you use face plate instead of chuck, tail stock feed is advertized 50 mm (in reality it is 30 mm), stuff that should lock doesnt and stuff that should not lock seizes, screws are bad, belts needs immediate replacement, handwheels wobbles, most part cast iron is pretty bad. In paper capacity was better than in reality. You just can't trust numbers. I'm not saying it is useless, but that it's usefulness is unnecessary limited, even considering the price. At that time I had no space for anything bigger and no patience to wait for anything better.

I have passed some old ones because they are totally shot. But for VT a klunker might be just the right one. It would donote bed and other bigger parts. Not everything is worth restoration or rebuild.

Pekka
Title: Re: Building a New Lathe
Post by: hanermo on March 10, 2015, 05:16:34 AM
I have an excellent Chester Craftsman, 12x24 - in rigidity, power and overall results, apart from fit and finish.
This is the heavy model.
Most chinese lathes are available in light and heavty versions.

Thus-
A 9x24", same length, is available in about 120-200 kg versions.
The Craftsman is 350 kg, and thus makes a huge, huge difference.

I only work with steel, and make stuff / have made up to 12" in diameter.

I suggest you would be very disappointed in a 9x lathe - they are the weakest in the bunch.
Title: Re: Building a New Lathe
Post by: vtsteam on March 10, 2015, 11:18:31 AM
Well, the spec here is a benchtop lathe to replace a 7" x 12" Gingery in a tiny 6'x8' shop, and fit on an existing benchtop, so really big or heavy machines, while better for sure, don't fit the requirements. Within the range of 7 to 9 inch lathes, and 12 to 20 between centers, a 9x20 like the Grizzly at over 250 lbs is probably even pushing it.

The existing Gingery lathe is probably about 60 lbs with a 28" overall length. I suppose I could come down to even another 7 x 12, but then it would really have to be better than what I have now -- stiffness to part off surely, or do reasonable size profile cuts without chatter, and quick change gearbox (or NC thread cutting) would be the attractions, otherwise, I'm fond of the little lathe I built, and certainly can deal with the "spares" issue -- I have patterns for everything and a furnace!

John R. as an owner of that specific 9x20 model, sounds good and I trust your judgement.

I do know that what Pekka says is also true in general, since I own, and have tuned up/modded where necessary Asian machines (bandsaw, round column mill drill, 50" slip roll, tractor mounted wood chipper, listeroid diesel genset) so I'd be going in with my eyes open. I wouldn't expect everything to be the way I wanted it. But I would expect lots of cast iron for a benchtop lathe, straight hardened ways, a good size hollow spindle with taper and low runout, and a working quick change gear system.. Those are what I miss most in the Gingery at present.

I have read up about what the complaints are for the 9x20 specifically: needs additional bolts to fasten carriage (published mod), lacks tumbler reverse, slowest speed is 150 rpm, no back gear, quick change gearbox only accomodates 8 speeds without manual gear changes. Mods exist to solve most of these, and I actually have a treadmill motor and controller (a common mod), which can solve the speed and reversing issues.

On the other hand, I keep thinking about what I'd do in building my own lathe. I think about it a lot. Doing things exactly the way I'd want them. You'd know it fit the space, You'd set the specs you liked. And it would probably cost less than a new one and yet have good size and quality purchased chucks, etc. I think about, what if I do end up modding an Asian lathe -- how much time will that save over starting from scratch, and will the result be equvalent? There's also the pride in something you made yourself. That, even now, makes it hard to think about replacing the Gingery lathe.
Title: Re: Building a New Lathe
Post by: vtsteam on March 10, 2015, 11:32:15 AM
I guess if I were to build a new lathe, I wouldn't have to make the spindle. You can probably buy a ground and tapered and keyed spare and bearings to fit in the size range we're talking about here for one of the mini-lathes. That would greatly simplify building the lathe. That would also give a common fit for chucks and collets, etc. and obviously, replacement spares would be available if needed in  the future.
Title: Re: Building a New Lathe
Post by: Joules on March 10, 2015, 11:43:33 AM
Or just look at it as the tool for the job.  Not all of us are blessed with the skill nor the patience to make our own machine.  Mini lathe is a good start.  You can have something that works, then slowly replace it like the old broom in the corner.

     
Title: Re: Building a New Lathe
Post by: mattinker on March 10, 2015, 12:20:27 PM
An interesting alternative is the Emco compact 8, the grand father of the 9 x 20 series at 8 x 18 it has many advantages like a more rigid cross slide. These lathes can only be found second hand now, but are well worth looking for. I got really lucky, I was given one that was virtually brand new, missing the motor. It is a nice tight basic little machine, thread cutting and feeds with change gears is a bit of a draw back, but it is still very capable!

Regards, Matthew.
Title: Re: Building a New Lathe
Post by: Jonfb64 on March 10, 2015, 01:19:33 PM
Hi Steve,

This may be just the ticket for you http://www.lathes.co.uk/stepperhead/

There are also Woking videos on YouTube.

I have often considered it myself. Perhaps one day when my abilities catch up with my dreams.

Jon
Title: Re: Building a New Lathe
Post by: Brass_Machine on March 10, 2015, 01:36:26 PM
If the 9x19 is pushing it, have you considered the 8x16? Grizzly has a version (http://www.grizzly.com/products/8-x-16-Variable-Speed-Lathe/G0768) as does little machine shop. the LMS Lathe (http://littlemachineshop.com/products/product_view.php?ProductID=3536&category=1271799306) is more money but has added features ie bigger motor, power cross feed.

OFC, I think you are itching to build on deep down.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on March 10, 2015, 03:42:40 PM
Matt, thanks, that would be one more to consider, though that would get into used machines, and with it being very unlikely to turn up in this area, would be hard to check out. I guess with a new machine bought unseen, at least wear and hidden damage are eliminated, and with a responsible dealer like Grizzly or LMS, a damaged or defective part would be replaced.

Jonindigoman, Holy Cow that is REALLY close to what I was thinking about. I have been interested in David Urwick's round column traingular gib machine ever since I saw it in old issues of ME. And I was wondering if I could add some of those features to a lathe if I built one. I was just thinking about that this morning as a matter of fact.

I also was thinking of a rectangular double beam ways -- similar to the Craftsman I have.

That's a beautifully finished machine. I do wonder if the stiffness is what I hope it will be. The proportions of the elevating head makes me wonder about how chatter resistant the lathe is. Also the cantilevered overarm supporting the tailstock is round section -- Urwick's was a sort of T bar cross section. I don't know what the comparative modulus of those sections is or the section size, but I have a feeling Urwick's design might have been stiffer.

I often look at proportions of things by eye, again, and kinda feel in my imagination what it's like with the forces involved. I'm thinking that doesn't have the stiffness I'm looking for. Maybe I'm wrong. Well, anyway, the overhead supported tailstock is one of those things that didn't appeal to me in the original design. Maybe I'm just stuck in a too traditional view.

But anyway, That's a beauty, and really close to what I was imagining. Great to see it like that, and how nicely it can be done! Thank you for letting me see that.

Yes Eric, I kinda do want to build a lathe. I do keep thinking it sure would be nice just to place an order and have a crate show up here with a lathe in it that I could just plug in and go.

But then I spend another hour daydreaming about what I'd do if I were to build one. How I'd do everrything on it.

I checked and a finished mini-lathe spindle from Little Machine Shop is around $40+. Hard to imagine not going that route if I built a lathe.

I wonder if the 8x16 and 9x20 use different spindles, or do they use the same, since the other specs look similar...?
Title: Re: Building a New Lathe
Post by: RobWilson on March 10, 2015, 04:14:26 PM
Hi Steve,

This may be just the ticket for you http://www.lathes.co.uk/stepperhead/

There are also Woking videos on YouTube.

I have often considered it myself. Perhaps one day when my abilities catch up with my dreams.

Jon

Oh Why did I click the link  :doh: now thats nice Jon


Do it Steve  you no you want to :poke: double dare you  :lol:

Quote
I have been interested in David Urwick's round column traingular gib machine ever since I saw it in old issues of ME

Do you have an issues number for that Steve ?

Rob
Title: Re: Building a New Lathe
Post by: vtsteam on March 10, 2015, 04:24:50 PM
3480 Rob.

edit:

also 3639, 3656, 3684

brilliant guy, also did some real interesting stuff with mesh displacers in stirling engines, and super long connections between displacer cylinder and power cylinder, with huge deadspace. Very very interesting. I go back to his stuff maybe once a year and re-read it.
Title: Re: Building a New Lathe
Post by: RobWilson on March 10, 2015, 04:33:07 PM
Interesting design  Steve

Rob
Title: Re: Building a New Lathe
Post by: RobWilson on March 10, 2015, 04:34:37 PM
http://www.lathes.co.uk/metalmaster/  :thumbup:


Rob


Edit ;  similar design http://www.lathes.co.uk/labormil/
Title: Re: Building a New Lathe
Post by: vtsteam on March 10, 2015, 04:36:59 PM
He patented the triangular gib key at one point, though it never panned out for him (expired). But you'd think with all the round column mill drills out there (including mine), somebody would pick up on it.
Title: Re: Building a New Lathe
Post by: RobWilson on March 10, 2015, 04:40:19 PM
I did think about doing it to my drill/mill 

Just found this Steve    http://www.model-engineer.co.uk/sites/7/documents/metalmaster.pdf   :dremel:


Rob
Title: Re: Building a New Lathe
Post by: vtsteam on March 10, 2015, 04:51:49 PM
....... Also the cantilevered overarm supporting the tailstock is round section -- Urwick's was a sort of T bar cross section. I don't know what the comparative modulus of those sections is or the section size, but I have a feeling Urwick's design might have been stiffer......

Ooops, just saw in another view that the overarm is not cantilevered, but has a support block down on the bed at the far end. Okay it makes a lot more sense to me now. I should have known, anything this well built has the issues figured out. In that case, it does look an exemplary machine.

If I do build something, it will be, uh, a little more shall we say, "workman-like" in appearance and construction. That's a monster of beauty.
Title: Re: Building a New Lathe
Post by: mattinker on March 10, 2015, 05:48:28 PM
There is an Urwick metalmaster group on yahoo. I've been a member for a very long time, there isn't much activity, none for years! There are CAD drawings and lots of interesting stuff.

https://groups.yahoo.com/neo/groups/URWICK_METALMASTER/info

Have fun! regards, Matthew.
Title: Re: Building a New Lathe
Post by: vtsteam on March 10, 2015, 10:27:40 PM
I uh, well, this doesn't mean anything....... uh impulse ordered a 7 x 14 mini lathe spindle. Just to see what it's like. Doesn't mean I'm going to build a lathe. It just seemed like something I ought to have for fifty bucks. I'm sure you all know how that is.......



Title: Re: Building a New Lathe
Post by: awemawson on March 11, 2015, 03:35:07 AM
What's this Steve? The Johnny Cash approach to lathe building, one bit at a time  :lol:
Title: Re: Building a New Lathe
Post by: PekkaNF on March 11, 2015, 03:51:52 AM
Can you put taper roller bearing(s) at the nose of that spindle? That should have you sorted.

Myford 10 has two oposing taper roll bearings on the spindle and it is pretty good. In theoriy it is not the best, but with two bearings it is pretty damn good for it's price.
http://cdn.instructables.com/F20/AN3I/HH2VZMRF/F20AN3IHH2VZMRF.LARGE.jpg

Much like this:
http://www.lathes.co.uk/elffers/img14.jpg

Here is plain angular front bearing and at the back there is a pair of opposing angular contact bearings:
http://www.myford.co.uk/acatalog/H21.-HEADSTOCK-SPINDLE--A1992-1120.html
http://www.myford.co.uk/acatalog/info_684.html

I think there is a document indicating how this is adjusted. If I remember it correctly first angular ball bearing was adjusted to take up play on front bearing and then second one was "snugged" into it to take up the play on the rear. pretty good at slow speeds, the "nose" bearing limits rpm.

http://www.myford.co.uk/acatalog/Specifications_of_the_Sigma_Lathe.html
This should have some indication of the size of relative parts.

Do I remember wrongly or was the front conical plain bearing was replaced with a single taper roller bearing at any point?

Anyways, if you don't need super high accuracy and very high speed, angular taper roller bearings offer very much load carrying capacity for the money. Yes they are limited on speed range and they are not cheap anymore if you need to buy "Class" over standard wheel bearing standard, and they heat up a bit because they need to be preloaded, but they take up a lot of load and abuse. AND honestly? How many of us can make a spindle and housing to required accuracy that are needed to very expensive "princess" bearings?

IMOHO. Have a good looks on taper roller bearings, design a grease nipple to them (they eat grease) and exit hole, you need seals and that should take care of it.

Pekka
* Typozzzzhh
Title: Re: Building a New Lathe
Post by: Fergus OMore on March 11, 2015, 04:41:34 AM
As a very young Goldstar, I was involved with what was the RAF Antarctic Flight. RAF Hendon- before it became a museum and all that.

But a lathe emerged called the Murad 'Antarctica' and then the 'Bormilathe' which I still want.  They are like hen's teeth but one alternative is the modified Myford Super7B of J.A.Radford and the working drawings for his 'Elevatiing Heads' are in his 'Improvements and Accessories for the Lathe' book- published by Tee. Again, his Milling Attachment is also interesting.

Regards

Norman
Title: Re: Building a New Lathe
Post by: vtsteam on March 11, 2015, 07:40:48 AM
Pekka, I uhhh forgot to mention that I uh... also ordered tapered roller bearings to fit.

No, Andrew.
 
Uhhhhhh 3 bits at a time.....   :lol:

But uhhhhhh, I'm not really building a lathe, just checking, you know what the possiblities might be.....

Fergus, I have Radford's book (collected ME articles) with the elevating heads, and he talks about the Bormilathe. The heads on his incredibly modified lathe were chain driven if. I remember correctly.

I couldn't get to sleep last night. I kept imagining how I'd do lathe beds. Now I'm half asleep in the morning and predicted to be the warmest day of the year, so far........
Title: Re: Building a New Lathe
Post by: Fergus OMore on March 11, 2015, 01:54:13 PM

Fergus, I have Radford's book (collected ME articles) with the elevating heads, and he talks about the Bormilathe. The heads on his incredibly modified lathe were chain driven if. I remember correctly.

I couldn't get to sleep last night. I kept imagining how I'd do lathe beds. Now I'm half asleep in the morning and predicted to be the warmest day of the year, so far........

This Chain driven idea is repeated by Prof Dennis Chaddock when he made the Quorn.
It is rather interesting because Radford was visited by Geo Thomas in NZ and Chaddock encouraged Thomas to write his things and Thomas and Tubal Cain( Tom Walshaw) used to  discuss Model Engineering far into the night at meetings! Then  Westbury and LBSC?
Let's not leave out G.P.Potts and his three spindles. I gave one away but still have two.
Then  Kenneth C Hart came in as 'Martin Cleeve' and building from only  half a new Myford ML7.

It was  heady mixture of experts. So I look forward your contribution.

Cheers

Norman

Title: Re: Building a New Lathe
Post by: Manxmodder on March 11, 2015, 02:12:30 PM
"I couldn't get to sleep last night. I kept imagining how I'd do lathe beds. Now I'm half asleep in the morning and predicted to be the warmest day of the year, so far"


Time to get the sun lounger out and have a snooze outside in the warmth........just remember to put your thermals on first :lol: :lol:
Title: Re: Building a New Lathe
Post by: vtsteam on March 11, 2015, 06:23:39 PM
It was so beautiful out and I was so tired I didn't know what I was doing and meandered down to Lesters old tyme machine shop. Ended up with some steel pieces. Just to see what they were like......

(http://vtsteam.com/Lathe/Steel.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on March 11, 2015, 07:22:35 PM
It was  heady mixture of experts. So I look forward your contribution.

Yipes! Definitely not at that level! Bad enough seeing in the last week a video of a homemade lathe that has micron accuracy, and then the Stepperhead in all it's shiny, innovative, and versatile glory. It's enough to make a guy say he isn't building a lathe, and then sort of accidentally have stuff get stuck together, purely coincidentally, that you can sort of turn stuff on, just like a lathe!

Title: Re: Building a New Lathe
Post by: Fergus OMore on March 12, 2015, 03:34:56 AM
Looked at all this lovely steel. Thought that you could actually make a lathe with steel rather than cast iron.

I went out to buy a little 1/6th 2880rpm motor really. The rest of the thing was not of interest. I was making one-for the second time. Result, I came back with a steel, fabricated Stent tool and cutter grinder complete with the intended motor. Works just like the real cast iron one.

Keep going

Norman
Title: Re: Building a New Lathe
Post by: Manxmodder on March 12, 2015, 09:12:31 AM
Just as long as we remember that Steve isn't really building a lathe but just visualising what the materials to build one would look like. I look forward to more photos of this 'visualising' process. :lol:

....OZ.
Title: Re: Building a New Lathe
Post by: PekkaNF on March 12, 2015, 09:26:33 AM
What is that square tube there for?

Steve - don't step into dark side.

One day I have to leave work early and get some visual aids for my project.

Pekka
Title: Re: Building a New Lathe
Post by: awemawson on March 12, 2015, 03:36:25 PM
Steve, I'm actually rather disappointed in you  :(

If you are going to REALLY make a lathe from scratch, first you need the iron ore and coke, cast your pigs and start mould making  :lol:

Now were it me, I'd find a suitable scraped lathe bed and try and fettle it back to life - unless I were keen enough to go down the epoxy granite route, which would be very interesting, home making a properly rigid bed is no small undertaking.
Title: Re: Building a New Lathe
Post by: vtsteam on March 12, 2015, 05:37:12 PM
Just trying to imagine sort of what a person could do, if they accidentally sawed up that tube into pieces and were trying to find a use for them. Maybe a sturdy ladder for their pet dachshund/border collie mix. Something that would last.... You'd probably want to get those rungs within a thou and square, or they wouldn't fit nice. Dogs is particular about that kind'o thing...

(http://vtsteam.com/Lathe/NewLathe1.jpg)


Pekka, oh that tube........  I tried to turn it over so the darkside didn't show -- but they're all dark.

Andrew, yes, I agree. But....... I'm not building a lathe, remember?
Title: Re: Building a New Lathe
Post by: Swarfing on March 12, 2015, 05:42:55 PM
Looks like a fantastic rigid bicycle chain you got there. You may need some heavy lumps place on each end to help bend it? it could take a long time for that to happen so you may need to stick it on a stand and wait for that to happen?  :thumbup:
Title: Re: Building a New Lathe
Post by: awemawson on March 12, 2015, 06:40:03 PM
Must be a bally heavy pet dog !!!
Title: Re: Building a New Lathe
Post by: Brass_Machine on March 13, 2015, 12:57:17 AM
Sturdy fence for garden gnomes? :thumbup:
Title: Re: Building a New Lathe
Post by: lordedmond on March 13, 2015, 02:58:37 AM
No it's a prototype camel back flat  :D

Stuart
Title: Re: Building a New Lathe
Post by: PekkaNF on March 13, 2015, 03:34:20 AM
Guaa...Now you did it. You stepped into the dark side. Lot of wonderful machine tools have been made with fairly standard fabrication methods. What was that italian CNC lathe? Also some propellors are being made that have time variable pitch.

Does it fit into any stress relieving oven you happen have nearby?

Don't tell me. You are NOT going to spoil that nice ladder by bolting something distantly flat on top of it?

Pekka
Title: Re: Building a New Lathe
Post by: Joe d on March 13, 2015, 07:56:55 AM
Wow Steve, you're going to get a prize from your local SPCA....

How many guys build their dog their VERY OWN lathe? :bow: :bow:

Joe
Title: Re: Building a New Lathe
Post by: vtsteam on March 13, 2015, 08:24:27 AM
Gosh, nobody believes me. Except Fletcher! :)

Fletcher says Pekka needs some stress relief....but he's kind of an opinionated little mutt who insists on doing things his own way. At this point I can only follow his instructions, Pekka. He's a combination of a herder, and an animal designed to attack badgers underground -- so you can imagine, he's very single minded when he's made any particular decision!  :beer:
Title: Re: Building a New Lathe
Post by: mattinker on March 13, 2015, 09:07:11 AM
Maybe a granite straight edge or a handy monumental mason gravestone off cut might get glued and bolted to the ladder to give it some stability!

Regards, Matthew.
Title: Re: Building a New Lathe
Post by: PekkaNF on March 13, 2015, 03:04:33 PM
Fletcher may be on to something...I took one can of brew. One of those days.

Are we going to see some dogged determination on this matter?

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on March 13, 2015, 03:36:19 PM
Oooh, don't let him see you do that Pekka.......he begs! :beer:
Title: Re: Building a New Lathe
Post by: Manxmodder on March 13, 2015, 04:21:34 PM
Pretty smart them Collies,but can a dog really build a centre lathe from a ladder,that's what I want to know. :scratch:.....OZ.
Title: Re: Building a New Lathe
Post by: BillTodd on March 13, 2015, 05:26:37 PM
Knock yourself up one of these ;-)

     


Title: Re: Building a New Lathe
Post by: vtsteam on March 13, 2015, 06:52:21 PM
Yes, yes Bill. I've already seen that in Rob's thread....rub it in whydoncha!

One of the main reasons I'm not building a lathe is because of that man and his micron precsison lathe! Standards have come altogether too high these days for a guy to feel comfortable making anything other than dog's ladders in a home shop.

Even then Fletcher is unusually lenient with me -- he saw the film, laid a paw on my shoe and said, "Don't worry about the ladder....sometimes crude work is attractive. You wouldn't want one of those lathes anyway -- just think, do ya really want to worry about whether on part of the granite bed was warmer than another while working, trying to hold that micron?"

I had to admit...... that might just take the fun out of it..... :beer:
Title: Re: Building a New Lathe
Post by: DavidA on March 14, 2015, 11:41:29 AM
The series by Dan Gelbart is very impressive.  But do we need that precision ?

I watched the series and after that the 0.0005" run out on my red lathe's spindle seemed horrific.
And his lab/workshop must have a crew dedicated to keeping it clean.

Guess I'll just have to tighten the headstock split taper bearing up a little more and hope for the best.

Dave. :(
Title: Re: Building a New Lathe
Post by: vtsteam on March 14, 2015, 12:05:59 PM
I do admire it though -- a great series and very cool lathe. Appropriate for some (though probably not all) of the prototype work he does. I know personally I wouldn't want to worry about temperature differentials (or I guess even dust particles) to the extent necessary to hold tolerances at the micron level. Especially not on something like a Pipe and Bolt engine. Or listen to air bearings and my painfully loud compressor every time I had to turn anything. Well, I'm sure his compressor is better than my thumper!  :)

Anyway, back to this dog's ladder......turned out I didn't own a 1/2" -13 tap yesterday -- too late to drive to town. Couldn't believe I didn't so spent at least an hour searching multiple locations, but nope, I guess not. So nothing to show. I played with the Ebay DC Motor and controller instead. Picked up a tap in town this morning, so on with the show.
Title: Re: Building a New Lathe
Post by: vtsteam on March 15, 2015, 09:56:00 PM
Milling:

(http://vtsteam.com/Lathe/MillBed.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on March 15, 2015, 09:57:29 PM
Scraping:

(http://vtsteam.com/Lathe/ScrapeBed.jpg)
Title: Re: Building a New Lathe
Post by: Brass_Machine on March 15, 2015, 10:28:27 PM
Nice! I need to learn to scrape...
Title: Re: Building a New Lathe
Post by: vtsteam on March 15, 2015, 10:44:23 PM
Heh, Eric here it is in a nutshell:

1.) Grab old tube of spot blue (or artist's Prussian blue oil paint).
2.) Squeeze tube to apply to rag. Tube cracks to allow getting all over hands, workbench, clothing, and eventually, face.
3.) Apply either to work (some people) or to flat surface (others) and rub work against flat surface to remove paint (some people) or add paint (other people).
4.) Scrape off spots with scraper. Either homemade or store bought. (Sharpen square).
5.) Squeeze more paint on rag if needed and apply to hands and face. Also work or flat surface
6.) Rub together. Scrape off spots
7.) Continue steps above for eternity. Or untll surface is as even as your aching back burning eyes, cramped fingers and paint covered safety glasses will allow. However, if you quit before 3 days and nights are up yer a wimp!
8.) Done
 :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

Title: Re: Building a New Lathe
Post by: Brass_Machine on March 15, 2015, 10:49:43 PM
Thanks Steve!

When I start building the new CNC mill I plan on getting it as accurate and as square as I can. Which means it will be a trapazoid and leaning!  :lol: :lol: :lol: :lol: :lol: :lol: :lol:

Eric
Title: Re: Building a New Lathe
Post by: vtsteam on March 15, 2015, 10:53:14 PM
These guys didn't make it past step 2....you don't use a hammer! Big project though..... :)

Title: Re: Building a New Lathe
Post by: RussellT on March 16, 2015, 04:54:37 AM
Hi Steve

It's a bit late now but I was looking at those square sections and visualising them turned through 45 degrees.  I thought that might make the sides more rigid as it would make the vertical footprint of the tubes higher - and it would mean that swarf would sit on them so easily.  Of course it would make them less effective as a ladder.

Of course that might be completely irrelevant as you may have something else to go on top.

Russell

Title: Re: Building a New Lathe
Post by: vtsteam on March 16, 2015, 09:01:06 AM
Hi Russell, yes there are ways to be added to the bed. I'm waiting for the steel to arrive. Making cross members larger or more numerous also works to increase stiffness at few dollars difference, but I judge things are what I want this way.
I pulled one out actually after trying.  :beer:
Title: Re: Building a New Lathe
Post by: RobWilson on March 16, 2015, 11:00:49 AM
Go on Steve , nowt like a good lathe build  :thumbup:   



Rob  :wave:
Title: Re: Building a New Lathe
Post by: Will_D on March 16, 2015, 05:08:39 PM
Always confuses me:

When you scrape do you scrape the white bits or the blue bits.

Re. blue going everywhere:

My old tube of blue was manky, 30 years old and more holes than a sieve.
So, in next tooling order popped on a tube of blue. New tube, clean fingers!  :beer:

WRONG WRONG WRONG.
They squeezed the order into a too small box and guess what suffered?

Not the expensive steels tools in their plastic boxes!

Oh No! It was the tube of blue on top of said hard robust plastic steel bits.

It managed to unravel the tripel fold at the end of the tube :Doh:

So now I haqve a BIG MANKY tube of blue!

Note to newbies: Buy the blue in the tin not the tube.
The tube may be bigger but you will be 300 years old when it runs out
Title: Re: Building a New Lathe
Post by: vtsteam on March 16, 2015, 05:18:11 PM
Well it kinda depends Will. If your part is blued, then you scrape the lighter bits. If the reference surface is blued you sort of scrape the blue bits, but it depends because it can also get into hollows behind the high spots so that way is cruder, and you have to think -- but if working down a general area early on, it's okay.

First way is more definite. But I ran into the problem of the blue not rubbing off at all because my reference straight edge was so slick and the pressure so light it didnt remove the high spot blue on the part.

So to start I went the other way, but switched back when I hauled my cast iron surface plate into the tiny shop heaved  it onto the bench. Then I could get enough pressure and the plate was just a little bit rougher. All around better than the straight edge. So, am bluing the part, as normal -- or normal for me........

Second day of scraping.....
Title: Re: Building a New Lathe
Post by: awemawson on March 16, 2015, 06:03:43 PM
Steve, after the welding have you normalised the assembly, heat cycle or whatever. If not is it not going to carry on moving for weeks?
Title: Re: Building a New Lathe
Post by: vtsteam on March 16, 2015, 09:26:18 PM
Andrew, it is a bolted structure, not a full welded structure. the few small welds are there to prevent crossmember shifting and they were laid down in a careful sequence, with cooling betwween each, and were peened. I don't guarantee it won't move, but I think it won't (within the tolerances that are acceptable to me). If it does, I'll have more scraping to do down the road. I chose hot rolled instead of cold rolled to further minimize warpage from milling and scraping.
Title: Re: Building a New Lathe
Post by: vtsteam on March 16, 2015, 09:33:39 PM
Rob!  :beer: :beer: :beer: :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on March 17, 2015, 11:39:51 PM
Still scraping. I did take a look at some Youtube scraping videos this evening to keep inspired. Things have changed since I built the Gingery lathe! There were no instructions on scraping at all on the internet in 2002, and I just followed Dave Gingery's book. Now there are a great variety of videos and many different tools illustrated, techniques, etc. That's helped quite a bit tonight actually, though I'm still not done with the bed after 3 days. Anyway, my instructions above were largely tongue in cheek, but if anyone really wants to know how to do it, there's a lot of good video instruction online and a variety of methods to choose from :beer:
Title: Re: Building a New Lathe
Post by: Fergus OMore on March 18, 2015, 04:18:07 AM
With increasing old age and infirmary(?), I gave up and for £250 ( I think) I got the bed of a Myford Super7B slideways ground and the very worn saddle built up with Turcite. It still leaves a fair amount to do. However, several points about my earlier efforts might be pertinent.

The first-after machining, is a map of the job. The second is a scraping cycle. Probably third is to watch the obvious high spots- ruthlessly removing anything blued ( regardless of great accidents of excess blue). In other words, you should have blue   areas ALL along the job. You might have several cycles  to get there. Imagine little islands showing -when the tide goes out and as the tide recedes( ie scrapings) more islands pop up. With that done, it is time to break the islands into smaller pieces by knocking the tops of the mountains off. You are then getting this dots per square inch thing. The next cycle will expose a new island amonst the ones that you had seen earlier. Again, it is progressively time to work done the job all the way.

I think that it worth a couple of mentions. The first is the constant re-honing of scrapers using diamond paste and the other is to lighly stone the work to remove the burrs from the scraper's cutting action.

Anyway, that was my experience- for what it is worth.                                                                                                                                                                                                                         As a postscript( memory returning), I have a pair of rubber rollers which probably came from an artist's stencil set up. Two diffrent sizes and to use an ink pad. Whether or not, it helps is not known.

Again, it is not mandatory to use 'blue' I have a tube of oil based Burnt Sienns artists paint as well as the 'Engineer's Blue' This might help those who don't quite pass the Ishihara colour test!

Norman                                                                                                                   
Title: Re: Building a New Lathe
Post by: vtsteam on March 18, 2015, 10:58:10 AM
Fergus, I've been stoning between passes, and the engineers or "spot" blue I have (from 12 years ago) is running out. It has the mandatory crack in the side of the tube in order to squirt blue out onto the hand that feeds it! Well I'm smart enough by now to wear gloves for this. I have a brayer (rubber roller) -- was once an artist, and used to oil paints and inks (though they have better tubes -- usually tin, not aluminum). I have Prussiaan Blue oil paint if I run out-- though it isn't as strongly pigmentd as the "real" stuff. But usable. I don't have a carbide scraper, -- HSS. But for the amount of scraping I will do in a lifetime, the purchase isn't warranted. For the scraper I sharpen frequently with a Japanese water stone. This puts a very fine edge on it.

The hard part is scraping a 3/4" wide by 26" surface and getting clean edge entry and end, and getting enough elbow room and foot space in a tiny shop for a position to do a proper cross hatch. I'm not ambidexterous. This is forcing me to be sometimes. But we're getting there. I predict it will be finished tonight.

This is not the bearing surface, btw. The ways will be added on top of this. And that will be scraped, too. I just want it to have a good start.  :beer:
Title: Re: Building a New Lathe
Post by: Fergus OMore on March 18, 2015, 12:04:06 PM

A 'Brayer'- well, I never! I'd got to things like 'Picker Buffers' from a very old firm that I had an association- for the spinning and weaving industry.
My carbide scraper is no more than a big piece of scrap  carbide insert tooling which is clamped to a traditional long ms shank. Happily, I have a decent diamond or two on a £100 T&C grinder and an undrilled faceplate on the lathe with diamond pastes( ex Vertex BSO dividing head)
Nothing more exotic.

So I'm following your your exploits with interest- and see an old man in a brown lab coat with completely black sleeves from iron dust and peering through a pair of Newcastle Brown Ale bottom specs and sweeping all the dustings away with both arms. :ddb:

I'm sort of dreading scraping the green mould off my villa in Spain- I feel for your pain!

Regards

Norman

Title: Re: Building a New Lathe
Post by: vtsteam on March 18, 2015, 10:54:21 PM
Green mold off a villa...... sounds good! Nothing green here yet, except envy of Spanish villas.

I didn't make my prediction tonght, still more scraping to do, almost there. Tomorrow morning for sure..... knock on wood. Boy this makes me want to work in wood. I think patternmaking is going to be the immediately following prescribed relief from this.

I probably could have cut 2 days out by really scraping with a vengance at first instead of fiddling with high spots after the first cut. I forgot what it was like a dozen years ago. You don't need to baby it, and hitting spots is only for the endgame. Now I remember again -- I used to get pretty rough with it, once I learned the hard way that you can either spend a week, or a day on a carriage slide, depending on your uhhhhh panache.

Tomorrow for sure....... :whip:
Title: Re: Building a New Lathe
Post by: awemawson on March 19, 2015, 03:27:20 AM
Steve, how does steel scrape? I'd imagine it's quite a different proposition to cast iron.
Title: Re: Building a New Lathe
Post by: dawesy on March 19, 2015, 04:53:14 AM
I envy you (sort of) the bed of the Churchill needs doing really but I'm not sure where I'd find a 6' straight edge to do it. Also how would one go about the 'V' sections?
Think a reground might be better in my case
Good work on yours though. I guess it's one of those jobs you don't rush.
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 08:42:43 AM
Andrew, I plead ignorance -- I've only ever scraped steel and aluminum. All the ways and slides on the Gingery are steel.

In my imagination cast iron scrapes as nicely as it machines -- happily if grey, and past the skin. But I dunno for real.

Cast aluminum needs a low angle and can take longer than you expect, even though soft. It can chatter and dig.

Dawesy, I don't know how they scrape long beds and prismatic ways (I think that's what they're called) but there's probably a video or web page devoted to it somewhere now. I have the opposite problem -- a 4 foot straight edge in a 6 foot by 8 foot shop, and a 2 foot lathe. :)

Actually, I've switched to a 2 foot cast iron surface plate which is better all around, for this bed -- it does 2 rails at a time, and shows twist without checking with machinist level, etc. I just hope the plate is true -- I bought it at auction and it looks venerable in age. Ive tried switching the bed around to different orientations, and the marking seems consistent. But that isn't an absolute guarantee. I thought of testing the straightedge and plate against eachother, but things are too cramped to be able to do that now.

A 6 foot straightedge must be quite a massive object..... how did they do 10 foot lathes? 20 ft lathes? There must be a way, with shorter reference surfaces.

ps.....didn't someone here cut down a straight edge awhile back? And scrape a whole kit of reference tools......that cut would take a lot of courage.....
Title: Re: Building a New Lathe
Post by: dawesy on March 19, 2015, 09:29:33 AM
The bed weighs about 200-300kg so a surface plate is out
I suppose there must be a way but my be has wear in the centre so I'd imagine id need to do the whole thing to get it flat and accurate. Prismatic ways sounds better than 'pointy edges '
Title: Re: Building a New Lathe
Post by: awemawson on March 19, 2015, 11:33:37 AM
I've had the beds of two Colchester Students, and my present Colchester Master 2500 slideway ground over the years, then had the saddles Turcited and ground, with minimal scraping to finish the job. And I spoilt myself on the current lathe and had all the cosmetic surfaces ground as well. No doubt the purists will howl me down but it seems a much better way of resurfacing a machine if a big enough slideway grinder is available. 
Title: Re: Building a New Lathe
Post by: BillTodd on March 19, 2015, 11:37:25 AM
Steve, after the welding have you normalised the assembly, heat cycle or whatever. If not is it not going to carry on moving for weeks?

Yes my thoughts exactly. Without heat treating to de-stress the welds you are wasting your time scraping. Even the machining will change the stress pattern and cause the whole job to move.

Title: Re: Building a New Lathe
Post by: Manxmodder on March 19, 2015, 11:49:06 AM
I've had the beds of two Colchester Students, and my present Colchester Master 2500 slideway ground over the years, then had the saddles Turcited and ground, with minimal scraping to finish the job. And I spoilt myself on the current lathe and had all the cosmetic surfaces ground as well. No doubt the purists will howl me down but it seems a much better way of resurfacing a machine if a big enough slideway grinder is available.

Andrew, grinding is the only method that can be used on lathes with induction hardened ways.

The Harrison models like mine,Mick's and John's all have induction hardened beds,is that thecase with the Colchester Master?....OZ.
Title: Re: Building a New Lathe
Post by: awemawson on March 19, 2015, 12:18:48 PM
Yes, but I thought that carbide scrapers worked ok on hardened cast iron :scratch:
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 12:59:58 PM
Most of us are wasting our time, Bill, and everything moves. Have you actually built and measured a bolted lathe bed of these dimensions and materials, with these size welds, peened and sequenced this way, so you can actually say what will happen? I haven't, and I'm willing to find out, and doing that isn't a waste of my time.

Before you tell me what to do with my time, please mike everyone on this forum's lathes and let me know what you find for an average tolerance. Then let me know when mine will warp past that point so I can switch it off in time.

Title: Re: Building a New Lathe
Post by: BillTodd on March 19, 2015, 01:06:30 PM
Most of us are wasting our time, Bill, and everything moves. Have you actually built and measured a bolted lathe bed of these dimensions and materials, with these size welds, peened and sequenced this way, so you can actually say what will happen? I haven't, and I'm willing to find out, and doing that isn't a waste of my time.

Before you tell me what to do with my time, please mike everyone on this forum's lathes and let me know what you find for an average tolerance. Then let me know when mine will warp past that point so I can switch it off in time.

No need to get shifty . it was simple friendly advice  :wave:
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 01:29:38 PM
Bill, when a guy is deeply involved in a project, the advice that what he's doing is a waste of time will likely not set well.

Let's get past it.  :wave:
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 01:41:51 PM
(http://vtsteam.com/Lathe/Scraping.jpg)
Title: Re: Building a New Lathe
Post by: RobWilson on March 19, 2015, 02:46:24 PM
Evening Steve


No sure if you mentioned it earlier ,but  will you be adding another length of material to the top of the scraped areas to form the ways ?     or do you have some other cunning plan ? 

Just looking at the bed , if two flats were added on top of the scrapped flats  to form a "T" shape it would be just like my Myford lathe bed .



Keep at it  :dremel:


Rob
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 03:54:12 PM
Yes, Rob, there are two pieces that go on top of the bed for the actual lathe ways. I've only been scraping their bedding here. The Gingery lathe was built the same way, though it was a single continuous piece on top, full width. The bed is first scraped and then the ways bolted down.

The present bed is through bolted together with 1/2" grade 5 bolts.  The square section tube is heavy wall  -- .25" and all members were milled and filed square and within one thou of each other in lenghth. There was no daylight when bolted and there is none now. The rails are hot rolled steel. The lathe bed was welded while bolted. The welds are only 1" long, and only located on top and bottom of the tubes, they were sequence welded and peened while cooling similar to cast iron welding practice to perform stress relief. Their function is to keep the cross members from shifting. The bolts and rails are the real structural connections. Both the top and bottom of the 3/4" thick rails of the bed were milled as an assembly prior to scraping.
Title: Re: Building a New Lathe
Post by: RobWilson on March 19, 2015, 03:58:57 PM
 :thumbup: So the bed will be very similar to my old Myford lathe Steve .

Two Square/flat  ways  :med:

Rob
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 04:20:41 PM
Similar to my Craftsman, too, Rob  :)  (and that micron tolerance lathe). The Craftsman has another feature I'll be borrowing, but we'll keep people guessing on that one til it's time to make it. Remember, early on I said this was going to be a combination of things I'd learned from both my lathes. :proj:  :scratch:  :beer:
Title: Re: Building a New Lathe
Post by: philf on March 19, 2015, 04:27:40 PM
:thumbup: So the bed will be very similar to my old Myford lathe Steve .

Two Square/flat  ways  :med:

Rob

And similar to the Schaublin 125 - a very fine lathe indeed. (I tried, but failed, to buy one from our toolroom when it closed down.)

http://www.lathes.co.uk/schaublin125/ (http://www.lathes.co.uk/schaublin125/)

Steve,

How are you going to fit the ways to the side rails?

Phil.
Title: Re: Building a New Lathe
Post by: mexican jon on March 19, 2015, 04:36:57 PM
Bill, when a guy is deeply involved in a project, the advice that what he's doing is a waste of time will likely not set well.

I used to think that a lot of things that people did were a waste of time  :scratch: but these days I'll send hours making or repairing something that would have been cheaper to buy  :loco: and when people ask why my normal reply is "Because I can"

Great work as usual  :D can't wait to see this progress  :nrocks:
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 04:42:52 PM
Phil, I'm going to set them upside down on the surface plate, epoxy as a bedding compound, let that kick overnight, and then drill and tap for countrsunk screws. That will keep things from shifting while trying to drill and tap, ensure eveness of the ways, won't depend on the epoxy except as a perfectly fitting bed, prevent the glue pressure from bowing the ways if it was screwed down while the epoxy was wet, prevent misalignment of the screw holes from bowing the ways, and probably a lot of other reasons I could think up.

If screw down in a day, the epoxy won't be absolutely rock hard (full cure takes a month for most epoxies) but will resist deformation at the screw pressure vs contact area not to depress the ways, yet there will be some tension in the screw holding the way to the bed.

At least that's my theory! :lol:
Title: Re: Building a New Lathe
Post by: vtsteam on March 19, 2015, 04:44:34 PM
Been thinking about making those screws, too.

Mild steel rod, the size of the head, turn the countersink shape and thread.

Kind of like a flathead screw still attached to the rod it was made from. Cut it off so it has a 1" long rod head.

If I screw that into a countersing hole with a wrench, I can then cut it off flush with a hacksaw while it's in place, file it down, then scrape.

Very similar to plugging screw holes when I was a boatbuilder, only the screw has its own plug built in.
Title: Re: Building a New Lathe
Post by: vtsteam on March 22, 2015, 05:11:04 PM
I cast some legs for the lathe yesterday, and today the lathe ways are being bedded down on top of the surface plate with a heat lamp over to cure in the tiny shop. I made a few small spacer gauges from scrap, filed to size, to hold the ways in alignment, and some others to check the overhang with. All looks good, now, I hope everything turns out okay tomorrow...
Title: Re: Building a New Lathe
Post by: S. Heslop on March 22, 2015, 08:46:23 PM
I'm enjoying reading this thread, and taking notes too for when I eventually get around to building a lathe.

Title: Re: Building a New Lathe
Post by: Joe d on March 22, 2015, 09:50:10 PM
Steve

I'm not sure that I will ever build a lathe, but I sure am enjoying following along.

Keep it coming!

Joe
Title: Re: Building a New Lathe
Post by: Zadig on March 23, 2015, 03:04:37 AM
I'm enjoying it too, great read.
Title: Re: Building a New Lathe
Post by: vtsteam on March 23, 2015, 09:21:41 AM
Thanks Simon, Joe, Zadig!  :beer:

It looks pretty good this morning -- the gap varies by only .004" over the full length, and the outside way width by .003" total. Within light scraping tolerances, so I hope to get through that process without a marathon of blue. Real happy with this construction so far.

With the electric heater and heat lamp on,  shop and lathe bed stayed warm overnight, Good thing since we dropped down to -13C last night.

(http://vtsteam.com/Lathe/BedBedded.jpg)
Title: Re: Building a New Lathe
Post by: Brass_Machine on March 23, 2015, 09:45:43 AM
Steve,

Was waiting to see how everything turned out. It is starting to look unmistakeably like a lathe bed. Quite nice. How much do anticipate this thing to weigh?

Eric
Title: Re: Building a New Lathe
Post by: PekkaNF on March 23, 2015, 09:49:55 AM
Nice one!

Really exited to see how do mount the headstock. I'm sure there is plan (sound effects here).

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on March 23, 2015, 10:06:39 AM
Thanks Eric, Pekka! :beer:

The bed now weighs exactly 50 pounds (22 kilos) and the headstock will be built with slides and gib and gib screws, just like the tailstock, so it can be bored while traveling along the ways. This makes the spindle bore parallel to the ways. Then it is bolted in position.

This also means that if the headstock ever needs to be removed, it can be replaced in proper bed orientation, as long as the gibs are tightened, without need for measurement. The slides in the headstock do not wear, nor do the ways where it is normally positioned.
Title: Re: Building a New Lathe
Post by: Manxmodder on March 23, 2015, 10:18:24 AM
Steve,you're doing a superb job on this. Good job on the alignment,hopefully that will reward you with a lot less scraping to get it all spot on.

As with most challenges it is the mindset that really counts,and what I see with this and many of your other projects is that you are a guy who applies himself to the project and problems really well.

Great job,keep it up. :thumbup:.......OZ.
Title: Re: Building a New Lathe
Post by: RobWilson on March 23, 2015, 01:36:17 PM
Aye !  , so were did the feet magic them selves from Steve ?   the foot fairy bring them through the night   :poke:


Its really is starting to look the part  :clap: :clap: :clap: :clap:


Rob  :D
Title: Re: Building a New Lathe
Post by: John Rudd on March 23, 2015, 02:41:43 PM
Only just read this thread...... :Doh:

What a fantastic job!  :bow:
I can't wait to see the machine finished and making its first turnings.....

What colour(color..... :D ) are you going to finish it in? Not some drab a Grey colour I hope.....

Keep it up..... :dremel:
Title: Re: Building a New Lathe
Post by: RobWilson on March 23, 2015, 05:10:45 PM

 Not some drab  Grey colour I hope.....



Dose that reminded you too much of Hull   John  ?    :lol: :lol: :lol: :)



Rob (BIG SMILE )
Title: Re: Building a New Lathe
Post by: John Rudd on March 23, 2015, 05:14:15 PM
Sadly it does Rob....never known such a xxxx hole......

Much prefer the more friendlier North Easterners from Gateshead or Newcastle.....or even Sunderland..... :)

I best go into hiding now....else the Hull mafia might come after me....
Title: Re: Building a New Lathe
Post by: vtsteam on March 23, 2015, 05:26:42 PM
Thanks so much OZ, Rob, John!! :beer: :beer:

Rob blieve it er not, them feet hopped right outer an old gas tank with with some plaster of Paris and some barbecue charcoal briquets in it! Here's a better pic:

(http://vtsteam.com/Lathe/Legs.jpg)

John, black, I think. It feels kinda old style so far.
Title: Re: Building a New Lathe
Post by: RobWilson on March 23, 2015, 05:31:01 PM
 :lol: :lol: :lol: :lol:  Its not that bad John , looked canny last time I was there  :thumbup:


 :clap: :clap: :clap: :clap: very nice Steve , they came out a treat  :bow: :bow:  ,,,,, aye Black is a good for a lathe  :thumbup:

All interesting stuff   this lathe building :med:


Rob
Title: Re: Building a New Lathe
Post by: John Rudd on March 23, 2015, 05:42:35 PM
Intrigued to know  what you going to make the head and tail stocks from?....saddle etc too?

Keep going.......lol :D
Title: Re: Building a New Lathe
Post by: vtsteam on March 23, 2015, 07:03:57 PM
John, I'll make the rest of the parts, but I did buy an upper tailstock casting for an Atlas 10" that I found on ebay. I really had designed the tailstock in my head already, but saw this one, and it was too cheap not to make an offer. It was priced  at $19, and I offered $13, almost hoping it wouldn't be accepted. But it was, and I received it today.

It's completely stripped, no internal parts, no base, all sold more luctratively by an ebay lathe breaker. But it saves me having to fabricate a tailstock body, and it's a nice heavy iron casting. Odd parts like this tailstock are cheap because of low demand, compared to the usual run of handwheels, change gears, etc. Not many lathes are missing a stripped upper taistock casting.

It's also larger than I'd planned -- I intended a 7 or 8" swing lathe, not a 10" but when I make the tailstock base I think I can lower the swing to 9", so I'll settle on that. This will be one of the very few 9" x 12" lathes extant, probably.  :loco:

I'm finishing the tailstock base pattern, now, and hope to cast it tomorrow.
Title: Re: Building a New Lathe
Post by: vtsteam on March 24, 2015, 09:53:17 PM
Casting the tailstock base

Pattern:

(http://vtsteam.com/Lathe/TailstockBasePattern.jpg)

The shake out. A simple combo sprue and riser right into the top worked. But just barely -- the metal nearly got sucked out of the sprue. This is Zamac, not aluminum, and its shrink characteristics are pretty impressive! Casting was perfect however. Casting is about 4" by 6" by 1" and used over 6 lbs of metal.

(http://vtsteam.com/Lathe/TailstockBasePour.jpg)

The other side. Some superficial sand fusion on the skin under the sprue where the metal was hottest exaggerated in the photo because of the lighting, but the casting is really perfect and is machining beautifully. It should be finished tomorrow.

(http://vtsteam.com/Lathe/TailstockBasePour2.jpg)
Title: Re: Building a New Lathe
Post by: mexican jon on March 24, 2015, 10:26:43 PM
Casting the tailstock base

Pattern:



The shake out. A simple combo sprue and riser right into the top worked. But just barely -- the metal nearly got sucked out of the sprue. This is Zamac, not aluminum, and its shrink characteristics are pretty impressive! Casting was perfect however. Casting is about 4" by 6" by 1" and used over 6 lbs of metal.



The other side. Some superficial sand fusion on the skin under the sprue where the metal was hottest exaggerated in the photo because of the lighting, but the casting is really perfect and is machining beautifully. It should be finished tomorrow.



Casting looks pro quality  :D

Can I ask  :scratch: what is the thinking behind casting a fairly simple part rather than using standard stock i.e. a piece of plate  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on March 24, 2015, 11:23:21 PM
Hi Jon, you could make it out of plate. But I didn't have any 1" thick plate. And more important to me, this time I wanted to use a better bearing pair than steel on steel. The Gingery lathe used aluminum and steel on steel for the slides. They work, but can be bettered. Bronze, brass and cast iron make good bearing pairs with steel. But I can't cast iron until warmer weather arrives here, and I didn't want to cast brass or bronze for this particular part, and wasn't sure I could with the small furnace (well found out I could later today as an experiment).

I bought some Zamac ZA-2 for experimenting and  building some small engines via lost foam casting last fall, and chose that particular alloy because I knew it had good bearing properties. It's not the usual choice for hobby greensand casters, but I wanted to try it.

Since I already had it, It seemed like a good choice here on the tailstock base. It's extremely tough (much higher tensile strength than cast iron in fact). Zamac and other zinc based alloys are commonly used in die-cast parts, which has given it a bad name, but those castings are usually very thin (often 1/8" or less) because it is so strong. In that thickness it can be shattered with a sharp blow. Because it is so thin, it's cheaap and used for mass produced products.

But it is a completely different material when cast into a heavy piece like this 1'" thick tailstock base. In a proper thickness, it's extremely tough, takes a great machine finish and in this case is a good bearing material. Very hard wearing, too. Seemed like a good idea under the tailstock.

Just how tough this stuff is was brought home to me when I spilled a small amount onto the ground today. it immediately ran down the slight grade. When cool I picked the splash up, and it was just a thin sheet of material. about 1 inch wide, 8" long, and less than 1/16" thick. I tried to bend it in half to break it into pieces, but I absolutely couldn't. If it had been cast aluminum, no problem. I put it in the vise and using vicegrip pliers, got it to bend double, but it still wouldn't break. I can only imagine what a 1" slab would be like.

It is also quite difficult to file -- it is fairly slippery, and also very tough at the same time. steel files much easier. Progress is really slow with zamac. This means it has very good wear properties.

Anyway a hard wearing, high strength, nice machining, good bearing material, which just happened to be on-hand, seemed like it was right for the job. So I used it.! :beer:

Title: Re: Building a New Lathe
Post by: bertie_bassett on March 25, 2015, 02:24:28 PM
looks like your making good progress!
Title: Re: Building a New Lathe
Post by: vtsteam on March 25, 2015, 03:52:11 PM
Hey Bertie, trying! So many interruptions today -- machined the outside of the base all over, gotta add some slots and things to fit the push peg for setover, the gib, the through bolt, and tap and thread the adjuster. Got a meeting at 5, so probably not today....

(http://vtsteam.com/Lathe/TailstockBaseMachined1.jpg)
Title: Re: Building a New Lathe
Post by: mexican jon on March 25, 2015, 10:21:57 PM
Hey Bertie, trying! So many interruptions today -- machined the outside of the base all over, gotta add some slots and things to fit the push peg for setover, the gib, the through bolt, and tap and thread the adjuster. Got a meeting at 5, so probably not today....


O metal porn  :lol:

That does machine nice  :clap: :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on March 26, 2015, 05:25:10 PM
Thanks John!

Kind of slippery to file though and hard. Nothing like aluminum or even steel. You really need a coarse file like a rasp to make any progress at all. I had plenty of practice flattening the ends of one of the clearance slots. Didn't have a small mill deep enough to do the ends.

I took lot of time over the slot that guides the top casting... it's all that keeps things square. I got a close sliding fit, so I'm happy. I just need to make the gib and add adjustment screws for that.

(http://vtsteam.com/Lathe/TailstockBaseMachined2.jpg)

Together:

(http://vtsteam.com/Lathe/TailstockBaseMachined3.jpg)
Title: Re: Building a New Lathe
Post by: tom osselton on March 26, 2015, 10:09:38 PM
Nice job!
Title: Re: Building a New Lathe
Post by: mechman48 on March 27, 2015, 05:01:21 AM
Sadly it does Rob....never known such a xxxx hole......

Much prefer the more friendlier North Easterners from Gateshead or Newcastle.....or even Sunderland..... :)

I best go into hiding now....else the Hull mafia might come after me....

What about your home county... Teesside... 'Smoggieland' or is that only where your inlaws live?... :wave:

George.
Title: Re: Building a New Lathe
Post by: John Rudd on March 27, 2015, 06:30:05 AM
George,
Pm sent....
John
Title: Re: Building a New Lathe
Post by: Fergus OMore on March 27, 2015, 06:58:23 AM
News just in!  Newcastle College is to open a Rail Academy in Gateshead. To replace aging old gits- if they can find them in the fog :beer:

Norman
Title: Re: Building a New Lathe
Post by: joshagrady on March 27, 2015, 07:08:51 AM
Hey Bertie, trying! So many interruptions today -- machined the outside of the base all over, gotta add some slots and things to fit the push peg for setover, the gib, the through bolt, and tap and thread the adjuster. Got a meeting at 5, so probably not today....

Out of curiosity, and speaking as an absolute ignoramus as far as casting is concerned, why didn't you include the slots in the initial pattern?  Even assuming that you left space for final machining, wouldn't that have saved some time and wear and tear on your body/tools?

I'm enjoying this thread, keep up the good work.

Josh
Title: Re: Building a New Lathe
Post by: vtsteam on March 27, 2015, 09:17:55 AM
Mostly impatience, Josh!  I thought about it and went, nah, just melt some metal.  :)

If I had to do it over, though, I probably would core it.

Two ways to do it -- either greensand core or baked sand core. The first is much faster, but trickier molding for a fairly narrow slot and requires a fair amount of draft. So much so that the slots are very tapered.

With a 1" thick pattern, and a 3/4" wide slot it gets questionable whether the core will break off when pulling the pattern. Rapping works well to create clearance for the perimeter of a pattern, but if there's a narrow core inside, it tends to shear the base. You want a lot of draft and just the right ramming. It can be done -- I have in the past, but it can be frustrating and take a lot of tries. Sand has to be just right.

A baked sand core is easier molding, but requires making a core box, and baking the cores and adding core prints to the pattern. Yes I know about sodium silicate and CO2, but that doesn't save most of this effort.

re sand cores, I'm the usual hard-headed low tech reactionary -- I don't mind 20 minutes of a nce molasses odor coming from a toaster oven. My wife is constantly baking, and they can go right in with the cookies, too. Baked sand seems surer to me -- my cores work every time and crumble properly. Seen a lot of failures online of the more sophisticated stuff, and I don't need the expense, shelf life problems, and the need and space for gas cylinders in the shop, etc. I just uhh borrow a tiny amount of simple materials from the kitchen and get-her done.
Title: Re: Building a New Lathe
Post by: Manxmodder on March 27, 2015, 07:14:30 PM
Steve,I just remembered where I recently saw this interesting home built lathe.
Check it out some of his ideas,might be some use to you.....OZ.

http://bbs.homeshopmachinist.net/threads/39202-Shop-Made-Tools?p=682515#post682515
Title: Re: Building a New Lathe
Post by: vtsteam on March 27, 2015, 11:02:48 PM
Well Oz thanks. Always interesting to see another hombuilt lathe.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on March 29, 2015, 06:16:15 PM
I finally got the gib fitted today:

(http://vtsteam.com/Lathe/TailstockBaseGib1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on March 29, 2015, 06:19:01 PM
And here's the tailstock casting in place on the lathe:

(http://vtsteam.com/Lathe/TailstockFit.jpg)
Title: Re: Building a New Lathe
Post by: Manxmodder on March 29, 2015, 06:38:29 PM
Looking good  :thumbup: I guess the process of drilling and countersinking the ways and tapping for the screwed anchor fixings must be coming soon.....OZ.
Title: Re: Building a New Lathe
Post by: vtsteam on March 29, 2015, 09:01:02 PM
Thanks Oz.  :beer: Been avoiding it, and having fun with the tailstock instead, since I have to lug the bed down to the cold big shop to drill and countersink on the mill, and make the screw plugs there on the Craftsman (if I don't just go with regular slotted screws).

Been warming up a little and the snow is shrinking and ice on the path is breaking up. I guess tomorrow I'll work on it. Thanks for the nudge!  :poke:
Title: Re: Building a New Lathe
Post by: Manxmodder on March 29, 2015, 11:11:04 PM
Steve, for what it's worth I'll share a little experience of my own with a similar fixing solution that I used on a homemade bench drill table.

The drill in question came to me without a table or support arm,so a round table was crafted from a 14" lorry engine flywheel.

The flywheel/table is fixed through the original holes where it was fixed to the crankshaft to a rotatable hub which is mounted into a boss on the support arm.

Firstly I countersunk the holes on the flywheel and used stock countersunk allen screws but it wasn't long before I realised that the hex key recesses were troughs for swarf to accumulate,and a nuisance constantly needing cleaning out so as not to interfere with the flush facing for the vice to set on.

It wasn't very long until I replaced the allen screws with some homemade flush topped ones and no more swarf trap problems since.

Just thought maybe you might encounter a similar problem when traversing the saddle along the bed if swarf gets in the screw slots/heads.......OZ.
Title: Re: Building a New Lathe
Post by: vtsteam on April 01, 2015, 08:03:45 PM
Oz, here you go.... Figured I'd better photograph them now before scraping, because I think they're probably going to be invisible after that:

(http://vtsteam.com/Lathe/WayScrews.jpg)
Title: Re: Building a New Lathe
Post by: Manxmodder on April 02, 2015, 09:02:17 AM
Spot on job  :clap: :clap: . Did you make the fasteners from barstock,or use of the shelf screws?.....OZ.
Title: Re: Building a New Lathe
Post by: vtsteam on April 02, 2015, 09:29:35 AM
Screws, Oz, countersunk to just have the slot come a hair above flush. These were wide head types. I don't know if I'll go back to scraping just now -- I feel like attacking the carriage pattern next...... :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on April 02, 2015, 02:01:06 PM
Wrong...............

started scraping again.
Title: Re: Building a New Lathe
Post by: RobWilson on April 02, 2015, 03:40:11 PM
 :clap: :clap: :clap: :clap: Looking canny Steve  :thumbup:


Any way I reckon your bed is way over engineered ,,,,,,,,,,,,, I mean using all that steel in all  :loco:   


Now this is a lathe bed  :)

(http://i1066.photobucket.com/albums/u410/RobWilson100/Technisches%20Museum%20Wien/P1000526_zpsohesdfqj.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Technisches%20Museum%20Wien/P1000526_zpsohesdfqj.jpg.html)

Notice the steel/cast iron ways set into the timber  :med:

(http://i1066.photobucket.com/albums/u410/RobWilson100/Technisches%20Museum%20Wien/P1000527_zps590umezu.jpg) (http://s1066.photobucket.com/user/RobWilson100/media/Technisches%20Museum%20Wien/P1000527_zps590umezu.jpg.html)

Just love the shape of those castings .


Rob





Title: Re: Building a New Lathe
Post by: vtsteam on April 02, 2015, 05:21:15 PM
I was just going to say, Rob, they really had a sense of beauty in everything they did. I imagine that when those timbers were new, the lathe was quite a sight. Just the clean lines of the pulley (not to mention the major castings) alone draws my eye.

Just up the Interstate from me in windsor Vermont at the Precision Museum they have a granite bed lathe. It's not as cleaned up as the one above, and not a clear photo, but you can see in the handwheel casting the same love of detail -- not to mention thin section casting ability!

There was also a cast concrete lathe in Model Egineer, made after the war, I don't remember which issue, but I thought it was really cool.

(http://i52.photobucket.com/albums/g8/lvanice/PM/DSC00234.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on April 02, 2015, 06:10:28 PM
I don't know if it's of interest to anybody, but here's what it looks like a little after beginning scraping. The blue is the high areas that need to be scraped. The left end is a little low also -- you can see the ends are un-colored. The total amount to be scraped until finish is probably only a few thousandths, but it's a long process getting there.  There's a lot of blue in this pass because I had just rolled the blue on the plate to start with.

(http://vtsteam.com/Lathe/Scraping1.jpg)
Title: Re: Building a New Lathe
Post by: Joe d on April 02, 2015, 06:14:34 PM
Don't know if it's of interest to anybody else, but I'm still following along and learning things...
never tried scraping yet, keep up with the tutorial, please!

Cheers, Joe
Title: Re: Building a New Lathe
Post by: tom osselton on April 02, 2015, 07:05:12 PM
Yep keep it coming one day I'll scrape more than my knee  :) I have found dad's scraper though it's just carbide braised to a old file. I'm thinking about a muller for casting season.
Title: Re: Building a New Lathe
Post by: vtsteam on April 02, 2015, 07:27:13 PM
Thanks Joe, I'm definitely learning from yours!

I'm far from expert at this but luckily, the difference between being really good at it and not so good is, I think, just how quickly you get the results you want. I bet a professional can get to the level I reach in a quarter the time, and probably carries on from there.

Anyway, the things I find helps are pretty simple. Don't go lightly to start with, dig in. There is a great temptation to scrape lightly to start and take every last bit of blue off. That's kind of finicky, and it means many, many more rubs and scrapes.

I'm a lot more ruthless now than I was at the start of the bed scraping. There are a lot of good videos for scraping, and one of them shows a pro with a scraper taking strokes that raise smoke each time!

Towards the end, you can start to get more careful and use lighter pressure. I find this time around that at the end of the day today I was a lot further along with the lathe ways than I was after 3 days on the lathe bed.
 
Stoning the work to remove burrs is important, as well as frequent sharpening (at least with a HSS scraper). Also being extremely careful not to get any tiny chips or debris clinging to the work when bringing it over to rub on the surface plate. Any  speck on the plate ruins the rub. Bits of scraping get under the bed each time you work on it. You have to brush the bench top off, and the work each time before rubbing it. But basically it's just a lot of time and repetition. Oh, imperative to wear gloves -- at least for me. I also frequently clean the plate with kerosene and re-ink.

Here's how far I got at the end of the day today. Quite a lot of progress for me compared to last go around:

(http://vtsteam.com/Lathe/Scraping2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on April 02, 2015, 07:31:02 PM
Tom  :beer:.  I bet that scraper works really well. And I wish I had a muller. Some day -- another project on the long list.
Title: Re: Building a New Lathe
Post by: Zadig on April 03, 2015, 02:50:37 AM
How many passes do you estimate it will take to get the top level? Nice colour on the blue, what brand are you using? Smashing thread.

Title: Re: Building a New Lathe
Post by: Kjelle on April 03, 2015, 04:53:09 AM
Steve, I have been watching people over at PM Practical Machinist) rescraping old lathes (and mills), but this is a whole new ballgame! There is this guy named Richard King that holds scraping classes who gives advice there too... (He went to Sweden last year (I think) and held a class! No I didn't go.)

I'm more than impressed by your work, I quietly watching, keep it up!!

Kjelle
Title: Re: Building a New Lathe
Post by: philf on April 03, 2015, 05:40:01 AM
Hi Steve,

Looking good so far.  :thumbup:

How will you get the underside of the ways parallel to your nice flat top?

Phil.
Title: Re: Building a New Lathe
Post by: RobWilson on April 03, 2015, 06:29:46 AM

Just up the Interstate from me in windsor Vermont at the Precision Museum they have a granite bed lathe. It's not as cleaned up as the one above, and not a clear photo, but you can see in the handwheel casting the same love of detail -- not to mention thin section casting ability!


(http://i52.photobucket.com/albums/g8/lvanice/PM/DSC00234.jpg)

Most interesting Steve , I had a look on there web site and it looks a good place to visit  :thumbup: ,the wife has been badgering me to go to the USA so  I may have to go and have a look see in person   .  :)


Rob
Title: Re: Building a New Lathe
Post by: S. Heslop on April 03, 2015, 06:49:05 AM
I don't know if it's of interest to anybody

It's definitely of interest to me.
Title: Re: Building a New Lathe
Post by: vtsteam on April 03, 2015, 08:43:56 AM
How many passes do you estimate it will take to get the top level? Nice colour on the blue, what brand are you using? Smashing thread.

Hi Zadig, thanks! I have no idea how long it will take me to get the top done. I just go at it until it is. The blue I'm using is an old tube of Prussian blue oil paint. I used to use Dykem Hi-Spot but it ran out. This isn't much different. The bluing is a little thick in the photo -- rolling it out thinner on the surface plate is better for detail, but I was just starting out.

Kjelle cheers! I saw a video where Mr. King is instructing a class on Youtube. He seems like a very nice guy -- and knowledgable, too.

Phil thanks ! I will have to do the bottom and all sides, too. And the carriage slides and tailstock. And the headstock too because it needs to slide for boring, initially. Everything that slides has to be scraped.

Rob a visit with you would be fantastic!  It's not a huge museum like that amazing German one you had pics of, but it is nice  restored mill buildong and has some interesting machines and displays. This area of New England (the Connecticut River valley) was once a great center of machining in the U.S. Now all but completely gone. But it was once called "The Precision Valley".

Simon, I'm really glad!  :beer:




Title: Re: Building a New Lathe
Post by: Zadig on April 03, 2015, 08:57:50 AM
I've just ordered a new tube of Dykem's blue. The tube I have used for decades is as old as I am and I'm in my fifties, it buggers me up trying to squeeze it out of the tube. It's biggest problem is that the witness is a little pale.
Title: Re: Building a New Lathe
Post by: vtsteam on April 03, 2015, 09:47:38 AM
Zadig, the worst thing about all these tubes is that they themselves are painted, and sometimes a tiny flake of the paint comes off onto my surface plate when I squeeze the tube, unoticed. Then do a rub, and find it messed everything up, and have to clean the whole plate again and start over. Any bit of debris is enough to support the ways high -- even the thickness of a flake of paint.

I noticed in the pro video I watched that he used a black spotting compound. I wonder what that was? It looked like it worked a lot better.

Also some pre-rub orange stuff that he called "orange". No idea what those were, but it would be great to try an alternative to the Dykem Hi Spot and artist Prussian artist colors. I think they could be improved upon -- and probably are.

Anyway, back to work....
Title: Re: Building a New Lathe
Post by: Joe d on April 03, 2015, 10:56:24 AM
Steve

If you want black, try some of this stuff...

http://www.kokopelliproducts.com/inlet.html

I've used it for inlay mortising on wood, works good!

Joe
Title: Re: Building a New Lathe
Post by: vtsteam on April 03, 2015, 06:04:25 PM
Since people  want to see these pics -- earlier today, progress, getting closer:

(http://vtsteam.com/Lathe/Scraping3.jpg)


Title: Re: Building a New Lathe
Post by: vtsteam on April 03, 2015, 06:07:24 PM
And at the end of the day, it was finished. That was better than last time. two days isn't too bad. but i think it was partly due to the fact that it had a good bed to start with.

(http://vtsteam.com/Lathe/Scraping4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on April 03, 2015, 06:10:19 PM
I tried the tailstock on it.

(http://vtsteam.com/Lathe/Scraping5.jpg)
Title: Re: Building a New Lathe
Post by: NormanV on April 03, 2015, 06:14:26 PM
Will it be the same tomorrow? I only ask from the frustration I have experienced from earlier scraping jobs.
Title: Re: Building a New Lathe
Post by: vtsteam on April 03, 2015, 07:15:45 PM
i don't know Norman, I can't predict the future! I certainly hope so. It was the same ths morning as it was last night......

Anyway, this evening I measured the thickness of the ways all around, inside and out along 5 stations and I wasn't able to measure a thickness variation -- my calipers are good to .001', so I can't tell any better than that. But i don't think I will need to do much if any scraping on the bottom of the ways. I'll know better when fitting the carriage. Maybe there will be a tight spot that needs a little work.

The closeness all over surprised me, because i knew i had taken more off in some areas than others. So I measured two cutoff pieces of the way stock -- They also measured the same all over. So it's pretty obvious that scraping really takes off a minute amount of material each pass. I probably did 20 passes and rubs and stonings over the last 2 days, thinking i did a lot. But not even a thousandth of an inch was removed.

Earlier today, I bought a 3/8" thick by 1-1/2" bar of hot rolled steel from Lester to make a narrow straightedge in case the underside needed scraping. A special straightedge would be the only way to check in there.

i also checked the widths of the ways gap and outside dimensions. The sides of the ways wll need some scraping as the tailstock is a tight fit at the ends. I knew the way stock was bowed very slightly when gluing up. It looks like about .004", worst case. That would be slow scraping on the top side, but should be faster on edge. I'll need to make the straightedge to start a reference edge on the ways.

(http://vtsteam.com/Lathe/TailstockFit2.jpg)
Title: Re: Building a New Lathe
Post by: RobWilson on April 04, 2015, 04:26:04 AM
 :bugeye: Now that lathe bed looks the mutts nuts Steve   :thumbup: , you must have the patience of a saint mate  :bow: :bow: :bow:



Rob
Title: Re: Building a New Lathe
Post by: Will_D on April 04, 2015, 05:33:06 AM
Also some pre-rub orange stuff that he called "orange". No idea what those were, but it would be great to try an alternative to the Dykem Hi Spot and artist Prussian artist colors. I think they could be improved upon -- and probably are.
I also watched that video and was wonering about the orange pre-rub?
Anyone any ideas?

I use Stuarts Micrometer Engineers Marking blue
Title: Re: Building a New Lathe
Post by: awemawson on April 04, 2015, 05:42:00 AM
Looking excellent Steve.  :bow:

Have you contracted 'Scrapers Elbow' yet  :ddb:
Title: Re: Building a New Lathe
Post by: bertie_bassett on April 04, 2015, 11:34:29 AM
blimey you've put some hours into that, looks great for it though!
Title: Re: Building a New Lathe
Post by: Manxmodder on April 04, 2015, 12:04:37 PM
:bugeye: Now that lathe bed looks the mutts nuts Steve   :thumbup: , you must have the patience of a saint mate  :bow: :bow: :bow:



Rob

He's just showing off with that scraping caper,what's wrong with using a block of wood and a bit of coarse sandpaper  :) :)...OZ.
Title: Re: Building a New Lathe
Post by: RobWilson on April 04, 2015, 12:15:50 PM
:bugeye: Now that lathe bed looks the mutts nuts Steve   :thumbup: , you must have the patience of a saint mate  :bow: :bow: :bow:



Rob

He's just showing off with that scraping caper,what's wrong with using a block of wood and a bit of coarse sandpaper  :) :)...OZ.


I would reach for the angle grinder OZ   :lol: :lol:     , Pete. sent me two carbide scrapers he had made himself , wow do they cut  :dremel:


Rob
Title: Re: Building a New Lathe
Post by: Fergus OMore on April 04, 2015, 12:48:28 PM
Also some pre-rub orange stuff that he called "orange". No idea what those were, but it would be great to try an alternative to the Dykem Hi Spot and artist Prussian artist colors. I think they could be improved upon -- and probably are.
I also watched that video and was wonering about the orange pre-rub?
Anyone any ideas?



I suspect that this is something called 'Burnt Sienna' which is an artist's colour and is a mixture of bauxite and iron oxides.

I've still the remains of a tube somewhere along with cobalt blue. I couldn't get the normal 'red lead' locally and settled for going to an artist's shop. At some car boot sale, I came back with the equivalent of rubber pickabuffer rollers( ex the spinning industry) and then made here at Gateshead.

Originally, there was family 'interest' in machine tools locally. Both went 'bust' then I began to look for places where there was the 'remains' of tooling and finally just gave up.

Then I found a very abused Super 7B and was going to send the bed to Myfords in Nottingham for grinding. Then someone suggested 'Blue Diamond' in Shildon who had a slideways grinder. They dropped the price to compete with the Myford one( who went into liquidation) and Blue Diamond slideways ground the bed and Turcited the saddle back to height.

The cost- apart from my transport to and fro- was a mere £250. I did the easy bits and gear cut the new gears.

Then the snows and wind came. Whipped the roof off the workshop. Then I got real problems with my wife's medical problems.

Nice to read about something pleasant. Thanks, Steve.

Norman
Title: Re: Building a New Lathe
Post by: Manxmodder on April 04, 2015, 01:05:29 PM
 Steve,you do realise that this machine could one day end up in be in a machinery museum collection somewhere.

So,maybe we need to give it a name now so those looking at it in future know some of it's history.

How does 'The Fletcher VT ladder lathe' sound ?  :)  Perhaps it should have a brass name plate attached with a Fletcher paw print included in the design.
Title: Re: Building a New Lathe
Post by: vtsteam on April 04, 2015, 05:46:48 PM
Holy cow, that's a lot of replies! Thanks boys, one and all!!! :beer:

I don't have scrapers elbow, but I do have the scraper's blues  :)

Angle grinder  :Doh: why didn't I think of that!!!!! (although, I do have to say that Bodger John's shaft finisher was pretty impressive.....)

Bertie, the time just flies when yer having fun! Some people go to the gym, I just lift a small lathe ways back and forth from the plate to the bench, and the bench to the plate, scraping a microscopic amount of metal off each time. A couple days of that, and shoveling snow seems like a nice break!

Norman, thanks buddy. I hope it does add something pleasant to read. Though it might get laughable yet because I haven't made the big screw up that is par for the course. My sig isn't there for nothing.

I don't know if it's raw sienna -- it looks kind of like a sort of wax in a tin, that "orange" -- pretty transparent for artists colors -- very pale orange. And it goes on before the rub -- I'll have to find that video and post a link so you can see it.

Sandpaper, Oz, well I'll tell ya........there's nothing wrong with filing during this stuff, even if you're scraping, as evidenced today.

Okay, so that brings me to today.  Remember I said I bought a piece of 3/8" x 1-1/2" x 27" hot rolled steel from Lester yesterday? Well today I painted some muriatic acid on it outside to take off the mill scale, but it was too cold work well, and it just did a partial job. I didn't have a container big enough to submerge it in either. So after a half hour of repainting it with the stuff and a large part of the scale gone, I rinsed it off and took it down to the big shop to mill one edge more or less flat, and brought it back to the tiny shop to scrape.

The idea was to make a small straightedge that I could use on the sides and bottoms of the ways to check and/or scrape them. I have a big 4' straightedge, but it's way too big!

So things were going swimmingly well -- it was nice to work with something light in weight, and that could be clamped in the vise. And sinc the edge was so narrow, it was really fast to scrape. But after getting ridof the initial hump in the middle and about 10 scrapes I wasn't making much progress. I tried scraping harder, but the blue just wouldn't move.

That's when I broke out the big heavy rasp and laid the scraper down. Ysee I finally remembered that 2 days work didn't even remove a thousandth of an inch (at least for me and my HSS scraper), so if there was 2 thousandths to remove........well I could do the math.

So, bottom line, don't feel committed to the scraper in moments like this, there's nothing wrong with filing the high part down if your blue isn't moving after some determined scrapes and trials.

I find that with a nice big file, no handle, laid flat on the work I can actually feel the high areas becaus the file has more bight there -- it sticks.

And a few minutes with the file really did the job. There was still scraping left to do. But not 4 days worth. I finished the straightedge this evening. It isn't pretty (yet).....but it's straight. It instantly let me find that the bend in the ways was really  mainly in one of the pieces, not both. So I started on the worst edge to turn it into a reference for the others. That way I can measure the variation and know where to scrape them to.

Again, I got only so far and then it slowed, so I broke out the file and went at it, removing several scraping days worth of material in a few minutes. By the end of the day I had my edge.

So that's the lesson fo the day. There's no shame in filing on a scrape job.

And also, don't put it off. Because if you go 10 scrapes and then file, you might as well have just done 1 scrape and then filed -- you're at the same point in the process either way. One might be a day quicker than the other!


Title: Re: Building a New Lathe
Post by: Fergus OMore on April 05, 2015, 03:44:13 AM
Always difficult to do 'long distance learning'. My experience WAS that hss scrapers were too poor and time consuming.
I bought one from Greenwood Tools in the UK which had detachable solid carbide blades( a couple). One was honed to do as you are doing- flat work whilst the other was ground on a green grit into a hook and again, finished on a diamond wheel. Actually, the wheel came from a commercial spectacle frame supplier and was for shaping lens blanks. It had become worn and I got it cheaply. It's still o my Stent grinder.

Not content, I salvaged a hollow leg from a pair of long pruning cutters to hold a piece of scrap carbide insert.
Most carbides are too blunt in small lathes but the advent of 'diamond' pastes and cheap so called diamond wheels came in. There was a lot of ballyhoo about carbon( diamond) and steel but I have never had problems.

What there was/ and perhaps is, is a write up in the Home Shop Machinist and Machinist Workshhop  for General and my date is 22/11/2005. There are 3 pages, I still have 2! In the body of the comment is reference to Projects Book 4- which I haven't got. Quelle surprise-stand by your ropes and fenders- I've found FIVE pages- then it all got light headed.

Probably, there is the opportunity to make up aluminium disks to take the various grades of paste.

---------------------------------------------------------------------------------------------------------------------------

My odd thoughts are unhappy about the safety aspect of Connelly's advice on making up pigments.
Heaven knows what the Health and Safety People would make of it today. I recommended buying a couple of artists tubes but making it-Hell, No!
-------------------------------------------------------------------------------------------------------------------------------

Again, 'Bob' one of my old mentors used to use 'soda water' or so he said when he scraped. I'll leave it at that

----------------------------------------------------------------------------------------------------------------------------

Have to wipe up the snots at the perhaps end of a bout of nasty 'flu'
Waiting to take tests now


Norman

Title: Re: Building a New Lathe
Post by: vtsteam on April 05, 2015, 07:24:29 AM
Well, Norman, I do appreciate that there are carbide and diamond for tools, but they hadn't yet descended upon the tiny shop from above, and a file, and old fashioned scraper and a bench stone were near to hand!

I remember once long ago in tidewater Virginia, we hopeful boatbuilder youngsters had a visit from an old master builder for a talk and instruction. One guy somewhat in awe, asked him what the best wood to use for framing was, in his opinion. "Why, white oak," he said. " Oh," said the apprentice, looking terribly unhappy, "I have a thousand board feet of oak I just bought. But it's red oak!"

"Well son, then that's the best wood to use for framing," said the old guy.



Title: Re: Building a New Lathe
Post by: vtsteam on April 17, 2015, 11:12:24 PM
A bit of a side excursion while I experimented with ideas for the electronic change gears, and I think I have enough of a proof of concept at this point. So I'm moving discussion here in this thread. It originally appeared in the "How Do I" forum under Elecronic Leadscrew thread.

As it stands now I have a FORTH program running on an Arduino board that will divide spindle encoder pulses and produce stepper movements to drive a leadscrew. And the ratios have been worked out to suit my intended leadscrew pitch, the encoder, and the stepper motor at inch thread pitches. I do need to test it at speed with the ordered encoder, but otherwise it seems do-able and everything works when breadboarded.

So back to the mechanical work on the lathe.
Title: Re: Building a New Lathe
Post by: vtsteam on April 18, 2015, 06:55:08 PM
I attached the new 600 line encoder to the toy motor and ran 375 rpm. The FORTH code handled the data rate fine all the way through 6TPI pitch - the coarsest I plan on. And likely requiring lower spindle speeds anyway, as it's usually found on larger diameter work.

However the stepper motor started to miss step at that spindle speed. Finer pitches worked fine.

It's a 20 year old used stepper. Not the motor that will go in the lathe. And I was only running 12 volts. I can run 24 v  and that will allow higher step rates.

So it does look like the high resolution encoder won't outrun the board. And the electronic leadscrew has a good chance of working out.
Title: Re: Building a New Lathe
Post by: vtsteam on April 20, 2015, 05:00:42 PM
Spent part of today scraping the edges of the bed ways . I finished the back outer edge and am using it now as a reference to scrape the front edge. After that is done, I'll work on the two inner edges.

Some things I learned long ago in woodworking are very useful while scraping an edge parallel with another. To correct a tapered board with a joiner, you drop the narrow end down onto the bed just past the cutter head, so a bit of uncut edge rests on the stationary table. This cuts progressively deeper at the wide end of the board. When parallel, you then take a full pass to remove the slight bump.

While scraping I realized that to bring an edge parallel to another edge you want to concentrate your scraping at the high spots closer to the wide end (if the high spots haven't fully reached either end). And leave the unscraped high area near the narrow end to support the straightedge. (Just like the stationary table on a joiner) .

Which seems anti-intuitive. The tendency is to want to scrape all the high spots off full length. The edge will then end up straight, but it will not be parallel, and you will eventually have to scrape to bring it in.

Instead, take off metal only near the wide end, and leave high spots near the narrow end untouched even though the narrow end hasn't been reached with marks. This will force the marking progressively down the wide end. Once the scraped portion is parallel by measurement, you can then continue to scrape evenly. all the high spots at both ends to bring the edge flat.

Hard to explain, but it does work. Anyway, thought I'd pass that on....
Title: Re: Building a New Lathe
Post by: rowbare on April 21, 2015, 11:51:34 AM
In one of the scraping DVDs I have (I think it is Richard King's) he describes scraping by zones to get rid of a taper. For example if you know that you usually remove about a tenth per pass and you are 1 thou high, divide the length into 10 zones. Starting from the high end, scrape the first zone. For the next pass scrape the first and second zones, for the third pass scrape the first, second and third zones and so on. Then once you have your alignment you finish scrape for flatness and bearing.

bob
Title: Re: Building a New Lathe
Post by: vtsteam on April 21, 2015, 12:25:30 PM
I think I might have seen that video years ago, Bob. Did it have a segment at the end showing the casting of straightedges?

Anyway, that method would work, too. I do kinda like mine -- it only takes occasional measuring, and no special marking. They both finish up the same way once parallel is reached.

I also want to reiterate from the scraping yesterday (with my tools) that on narrow work, one filing is worth ten scrapings, and if anything is more than a thousandth off I can cut down hours of work by grabbing a handle-less coarse file, laying it flat and going at the high spots until I reach a thousandth or so rough tolerance. Nothing wrong with files!
Title: Re: Building a New Lathe
Post by: vtsteam on April 22, 2015, 09:32:19 PM
I've finished scraping 3 of the 4 way edges today and the fourth is about half way done. Just a progress update. It will be nice to switch to pattern making and casting shortly.
Title: Re: Building a New Lathe
Post by: PekkaNF on April 23, 2015, 03:01:13 AM
This is a thread I follw with great interest.

Any informative pictures on color transfer and scraped marks?

Pekka
Title: Re: Building a New Lathe
Post by: Joe d on April 23, 2015, 07:58:14 AM
Sounds like you're making good progress Steve.

Looking forward to the first turning on the Model 1 Mark 1 Fletcher Ladder Lathe :clap:

Joe
Title: Re: Building a New Lathe
Post by: vtsteam on April 23, 2015, 09:25:02 AM
Thanks Pekka, Joe.  :beer: I keep thinking photos of scraping must be as boring to people as scraping itself. But I can see that maybe a couple pictures of the blue part might be useful, so I'll take them.

One point I want to make about files. They are NEVER flat in my experience. If you realize that you can use it to your advantage (and if you don't, they will mess up your work).

So, flip your files over when filing and get a feel for which side is cutting in the center and which side is cutting at the ends. imagine how that is cutting the work. And then use the appropriate side for what you want to do and apply pressure in the area you want to cut, as well as keeping the stroke length right not to cut into areas you don't want.

With a file laid flat, you will be able to feel resistance in it along its length, and know where it is cutting.

On this level of flattening things, filing involves a lot of visualization and feel, you cannot rely on just the idea that a file is flat and rub it over a surface, because, guaranteed you work will suffer. Is the file following a curve, or cutting the ends like a double-ended scraper, or rocking at the center. You must feel and imagine what the action is.

And of course frequent checking to make sure you really are cutting where you want. This is especially important if you are new to this. As you get more familiar, knowing what file face you are using for a particular high spot becomes second nature.
Title: Re: Building a New Lathe
Post by: Brass_Machine on April 23, 2015, 12:06:32 PM
Thanks Pekka, Joe.  :beer: I keep thinking photos of scraping must be as boring to people as scraping itself. But I can see that maybe a couple pictures of the blue part might be useful, so I'll take them.

Nah, not boring at all. I find it interesting and it helps some of us.

Keep up the good work!
Title: Re: Building a New Lathe
Post by: vtsteam on April 24, 2015, 08:43:16 PM
Okay, so here's the 4th edge blued up. It's been filed and scraped some already. the blue has begun to move on the left from a small spot to start with. the high area on the right is getting larger, too.

If the edge was also tapered and the right side was the wide side, I would  scrape everything blued except a small patch on the far left, which I would leave. When the straightedge was placed for a rub next go-round, it would ride up on the high spot on the left and mark high spots mostly toward the rght, which would force stock removal along a new straight line, angled inward more on the right.

Scraping those would have the effect of reducing the taper, yet maintaining a straight line. I'd repeat this process until the width of the scraped areas all along the ways measured the same -- in other words, parallel with the reference edge. Then I would continue scraping the whole ways, including the part left earlier to bring the whole surface into truth, and now parallel, too.

(http://vtsteam.com/Lathe/Scraping6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on April 24, 2015, 08:51:13 PM
Scraped in one direction:

(http://vtsteam.com/Lathe/Scraping7.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on April 24, 2015, 08:56:05 PM
Scraped back 90 degrees, before stoning off the burrs:

(http://vtsteam.com/Lathe/Scraping8.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on April 24, 2015, 09:02:13 PM
After quite a few more passes, progress. Most of the edge is getting blued. Only the far right is a bit shallow, and likely the next pass will show blue there,too:

(http://vtsteam.com/Lathe/Scraping9.jpg)
Title: Re: Building a New Lathe
Post by: S. Heslop on April 24, 2015, 09:14:02 PM
Hope I didn't miss something, but how are you measuring the taper? And how are you keeping it square to the top surface?
Title: Re: Building a New Lathe
Post by: vtsteam on April 24, 2015, 09:28:33 PM
I measured the width of the way piece in this case, since the other edge is the reference and I want them to be parallel.

As far as keeping it square, I did that by hand and eye.

Of course there's a bit of a hedge in doing this.  I removed a total of .004" in all of that scraping. The liklihood that I would be off by that much -- the max possible -- all to one side of a .375" width is nil.

Oh, also, the edge picked awhile back for the reference edge was the edge which, by measurement, was the most out of true. That one was trued up first, and then the others measured from that.

Title: Re: Building a New Lathe
Post by: vtsteam on April 29, 2015, 09:25:02 PM
It's been tough to work indoors now that warmer weather has started -- so much to do around the yard and house. But I have been taking a little time each day to do at least some small job on the lathe.

Here is a pattern I just finished for the carriage casting:

(http://vtsteam.com/Lathe/Carriage1.jpg)


Title: Re: Building a New Lathe
Post by: Brass_Machine on April 29, 2015, 10:48:44 PM
Looks nice Steve. I am anxious to see you finish this guy...
Title: Re: Building a New Lathe
Post by: vtsteam on April 30, 2015, 09:24:22 PM
Thanks Eric!  :beer: Might take awhile. It threatened to rain today, but I took a chance and did manage to get the part cast late in the afternoon. It's a somewhat tricky pattern with a parting line up a short way, and needing to be coped down in the center section, so I had to bed it in a false cope first.

Plus there's a greensand core that luckily held together. And  it just barely fit in my larger flask. I had only a half inch to the edge at the riser. I was worried it would break through. The whole thing worked out first shot, so I'm happy. And it didn't rain! A few drops now in the evening. The raw casting....about 7 lbs:

(http://vtsteam.com/Lathe/Carriage2.jpg)
Title: Re: Building a New Lathe
Post by: Brass_Machine on April 30, 2015, 09:41:01 PM
That's it, I am going to VT this summer so I can see some casting done in person.

Looks nice!
Title: Re: Building a New Lathe
Post by: vtsteam on April 30, 2015, 10:13:20 PM
Sure Eric! But I don't have much interesting high tech stuff.

That pattern was made of white pine scraps left over from building the bench. The casting was molded in plain sand mixed with fireclay (not even bentonite) -- ten years old, too. And melted in a plaster of Paris lined furnace, with a simple homemade half inch EMT tubing propane burner. And no blower. All this stuff detailed elsewhere on this forum in various places, so there's not going to be a whole lot new to show you!


Title: Re: Building a New Lathe
Post by: Brass_Machine on April 30, 2015, 10:46:53 PM
As much as I like to learn... I always do best with seeing it in action. Still exciting to me.

Title: Re: Building a New Lathe
Post by: awemawson on May 01, 2015, 01:50:54 AM
Very nice Steve, that's come out a treat
Title: Re: Building a New Lathe
Post by: Meldonmech on May 01, 2015, 03:15:36 AM
 
   Hi Steve
                              Nice sharp casting, looks great.

                                                                                     Cheers David
Title: Re: Building a New Lathe
Post by: vtsteam on May 01, 2015, 04:54:33 PM
Thanks Eric, Andrew, David! :beer: :beer: :beer:

Machined the slides and cleaned up the top some to get ready for adding the carriage way:

(http://vtsteam.com/Lathe/Carriage3.jpg)

Title: Re: Building a New Lathe
Post by: RobWilson on May 02, 2015, 04:08:18 AM
 :clap: :clap: :clap: :clap: Nice going Steve  :thumbup:


Cracking looking casting , the lathe is starting to look like a lathe  :med:


Rob
Title: Re: Building a New Lathe
Post by: awemawson on May 02, 2015, 10:20:36 AM
No, Steve told us early on in the project, "It's a ladder for the dog"  :scratch:
Title: Re: Building a New Lathe
Post by: vtsteam on May 02, 2015, 11:16:46 AM
Oh, right....forgot!  Poor Fletcher, I got carried away with the decorations. I'm just calling it a lathe -- because it sort of looks like one, not committing to anything. Just kinda putting pieces together to see if it might work that way, in case I do build a lathe some day.

Course, with all these geegaws on it now, I'm wondering how will I ever train him to climb up and paint the house?

Thank you kindly Rob! Might cast a decoration today sortof in the shape of an apron.

If I don't get roped into tilling the garden. Been hiding out in various locations until the family goes to town..... :whip:
Title: Re: Building a New Lathe
Post by: Manxmodder on May 02, 2015, 01:02:57 PM
Great job, Steve,it's looking really good  :clap:. Fletcher won't be too down hearted just yet,with the carriage and lead screw installed he probably thinks you've gone the extra mile and built him a mechanical dog lift rather than a basic ladder. I get the feeling he's gonna feel cheated and disappointing at a later stage though.....OZ.
Title: Re: Building a New Lathe
Post by: tom osselton on May 02, 2015, 02:46:04 PM
Looking good Steve!
Title: Re: Building a New Lathe
Post by: vtsteam on May 02, 2015, 03:04:47 PM
Thanks Oz, Tom!  :beer: :beer:

I got the apron cast, this time in aluminum since it doesn't have any sliding surfaces. I timed the melt -- it took 17 minutes from charging the furnace until i was pouring. Next time I'd like to weigh the propane tank before and after. I wonder how much propane I'm using? I don't think it's a lot through that small burner. and I'm running 7 psi at partial throttle.

(http://vtsteam.com/Lathe/Apron1.jpg)
Title: Re: Building a New Lathe
Post by: PekkaNF on May 02, 2015, 03:17:43 PM
This might be noob-question, but Why is there so litlle meat on cross slide casting on front shear? Looks awfully little surface area on this picture?

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on May 02, 2015, 03:36:14 PM
Pekka it's quite a bit of support in reality (pics don't show it as well) the shears are 9" long and made of zamak ZA-2, which is  stronger than CI. There will be 1/4" 1" x 9" steel underneath. We're talking 9" x 7/8" total thickness along the way for the front shear.

Also under the 3" wide center section, you're looking at about an inch of upper section thickness bearing on the way.

By contrast the Gingery has 2-1/4" wide center section, and no support wings, and is cast in aluminum. So, 2-1/4" of support along the ways.

I just judged it was sufficient. And a heck of a lot more support that the Gingery, on what is basically the same size lathe.  The rear shear was made thicker because it lacks width, but the front shear section is pretty wide so I didn't think it needed more support. Also I wanted to be able to tap and bolt nto the reaar shear -- that was already do-able in the front, past the sliding edge. There is 7 pounds of material in that casting, and I didn't want to pour more than I felt necessary with the crucible topped up as it was.

In other news.....here's the back of the apron in case anybody is interested. the points are from vents pushed up in the sand, and as you can see there isn't any shrink cavity, so should machine easily.

(http://vtsteam.com/Lathe/Apron2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 02, 2015, 05:59:07 PM
Here's how the steel retainer piece  (foreground) goes on. I've clamped it temporarily to bottom of the carriage. It gets screwed in place. Likewise the cross slide (sitting in place behind) is a slab of cold rolled steel and will be screwed down when the time comes.

(http://vtsteam.com/Lathe/Carriage4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2015, 01:37:29 PM
I've fit the slides under the carriage, the apron, the gib, the gib tightening screws, and the cross slide ways. The completed carriage now slides freely along the scraped ways without play in any direction.

(http://vtsteam.com/Lathe/Carriage5.jpg)

Title: Re: Building a New Lathe
Post by: philf on May 06, 2015, 01:54:36 PM
Steve,

Looking very nice I like the 'retro style' feet.

Has there been mention of the headstock? Is it to have plain bearings or ......?

Phil.
Title: Re: Building a New Lathe
Post by: RobWilson on May 06, 2015, 02:11:33 PM
 :bow: :bow: :bow: :bow: :bow: now thats looking real canny Steve   :clap: :clap: :clap:


Rob  :thumbup:
Title: Re: Building a New Lathe
Post by: Manxmodder on May 06, 2015, 02:19:55 PM
Yep,it looks a top job,Steve.  I'm well impressed with the standard of workmanship :bow: ,it's going to be a great asset when finished....OZ.
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2015, 02:29:05 PM
Thanks Phil! Roller bearings. I bought a new replacement spindle and matching bearings for a mini-lathe early in the thread, so will install those together in the headstock when the time comes.

(The lathe is just sitting on the feet now, not attached. Had to lift it up to higher to attach the apron.)

Thanks Rob, Oz!  :beer: :beer:

Title: Re: Building a New Lathe
Post by: Brass_Machine on May 06, 2015, 03:45:15 PM
Yup. That is looking good. I expect it will  out perform the Asian minilathes (like mine) without breaking a sweat!
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2015, 09:05:57 PM
Thank you Eric! I hope it will last me as the main machine for as long as I can make things -- if I'm lucky that's still a while yet. So I'm trying to make it solid and accurate, within my capabilities. If it looks any better than earlier stuff that's Rob's fault, because his work always makes me try to do better than I have so far.

And of course the encouragement people here are so generous with and the inspiration of their projects keeps me going back to the shop to make things and put up pictures.

Things don't always go well, of course, I had a disappointment this afternoon in trying to make a tap for acme 1/2" - 10 TPI. These cost $50 if you can find them. That's hard to justify, especially since I need to save for a chuck eventually.
So I've been collecting info on tap making.

I tried a method I saw on another forum after a web search, which showed a tap made by simply grinding 4 flats at the end of some threaded rod, set at a taper of about 30 degrees. This just didn't work for me. I tried it with various angles, and unhardened and case hardened (with kasenit) on a scrap piece of aluminum, I simply couldn't get it started. It would just chew up the aluminum and wobble out of line. I don't know what I was doing wrong.

Seems to me the thread is just too coarse for this kind of tap, even though the reference I read said acme taps made that way had been successful. The picture though in the post was of a very fine thread 60 degree tap, and the example had cut into brass, which I think would thread much cleaner and crisper than aluminum.

So tomorrow I will probably try again, but this time attempt a conventional machined tap, turned on the lathe to an entry taper, with flutes, and some rake angle.  And I'll case harden it from the start.

So, fingers crossed it will cut zinc alloy cleanly.

Title: Re: Building a New Lathe
Post by: awemawson on May 07, 2015, 02:13:19 AM
Steve, tapping coarse acme threads, I've always bored and threaded them undersized in the lathe then used the tap as a finishing pass.
Title: Re: Building a New Lathe
Post by: PekkaNF on May 07, 2015, 03:11:45 AM
Once I was thinking of buying a tap roughly same size trapezoidal thread 12 mm and 2 mm lead....One Brittish tap maker I called said that that they would need to charge about 140€ of it, it needs to be long, cut gradually and all in all it is hard to make one that will work manually and will not break.

I have been reading of people drilling oversize hole, using normal V-thread tap (same lead) to remove some metal firs. I believe it's not too easy.

Also that size internal threading will not be easy. When you substract thread part out of the diameter, there is not much left for threading bar core diameter.....Would probably need to be as short as possible and you many need to to make two bars to optimize thickness and cutting tooth lengt - bit like first cut / second cut tap. Helix angle and all. Did not want to go there

So, I'm designing that part a little fatter to make room for ready made nut. Left handed nut and trapezoidal bar are not cheap, but cheaper than the alternative.

Pekka
Title: Re: Building a New Lathe
Post by: awemawson on May 07, 2015, 03:25:25 AM
Have you considered a quashed Acetal nut?

Never done it but some swear by them - turn / bore your plastic blank with a core sized hole, place in suitable outer clamp over the acme male thread and warm and tighten. The plastic flows around the thread. You can then turn the o/d to suit. I believe a dusting of graphite powder is used on the male

http://bbs.homeshopmachinist.net/archive/index.php/t-43645.html
Title: Re: Building a New Lathe
Post by: Pete W. on May 07, 2015, 04:27:39 AM
Hi there, Steve,

This project is looking very impressive so far.

Regarding your problem with taps, I've just clicked my way through about twenty pages of the Model Engineer forum until I found this:

  http://www.model-engineer.co.uk/forums/postings.asp?th=103007&p=28 (http://www.model-engineer.co.uk/forums/postings.asp?th=103007&p=28) 

I knew it was there somewhere!  I hope it helps. 
Title: Re: Building a New Lathe
Post by: Will_D on May 07, 2015, 05:36:52 AM
What about a multi-stage casting process to end up with bronze nuts?
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 07:44:17 AM
Thanks Pete, Will!  :beer:

Will, In this case I need to tap the casting. It's a little different than the usual method of a cross slide leadscrew nut. Gingery style. Anyway, can't cast for this particular job, and impractical to internal thread on the Craftsman with the amount of overhang, so a tap, either made or purchased is the right tool for the job. Later I can cast nuts with threads, and will do that for sure with the half nut.

Pete, thanks. Those taps have a really long taper, which is probably a very good way to do it, I'm thinking. The problem yesterday was, I believe, too short a taper, and too shallow a rake angle -- which is a result of the particular unusual way of making a tap. Apparently it is a very old way of doing it -- but I just think t's not good for a coarse acme thread, and maybe my practice piece of aluminum wasn't th best choice to try it out on, or maybe these need a big clearance hole and have low thread engagement.

I don't know what was wrong in my case, because I do believe that the person who recommended it was successful in cutting acme threads. One of those cases where you have to see the tap and operation to know what was different about it from what you are doing, rather than just read a word description.

Well today, more tap experiments.......
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 08:31:23 AM
Oops, missed your replies Andrew and Pekka -- thanks for the suggestions -- and as I said this isn't tapping a nut, but the operator end of the carriage casting itself.

Pekka your tech description is helpful. I just remembered that I do have an acme tap, a 1" x 6 TPI (I think) , and it works fine, so I'd like to take a close look at that, check the rake angles, taper angle, relief, etc. since it cuts great. I made a drive nut for my horizontal mill with it in steel, just hand tapping. Seems like 1/2" x 10 should be a piece of cake by comparison, with the right tap.
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 08:44:13 AM
Here is one site I was looking at for tap making info.

http://mckgyver.pbworks.com/w/page/20654129/AcmeTap

Notice that the chart shows the tap rake angle as low as 0-3 for cast iron, and relatively low for brass (just as we typically reduce top rake angle for lathe tools, and flatten drill lips for that material) but relatively high rake angle for aluminum and zinc die castings.

That makes me think that the first tap I made, following the old style 4 bevel end on a coarse thread produces a very low rake angle, and while it might work for finer pitches in brass (as shown on the forum post I saw) or cast iron, would definitely not work with coarse acme in aluminum.

Since the ultimate use will be on zinc, I'm going to say a 10 degree tap rake angle would be minmum, according to that chart.
Title: Re: Building a New Lathe
Post by: Pete W. on May 07, 2015, 09:18:39 AM
Hi there, Steve,

The tap-making whose link (another Andrew!) I posted earlier was for a square thread, I guess acme ought to be easier.  I don't think he intended to cut many threads with his taps - his project is steerinng gear for a pair of traction engines (but quite big ones!!!).

Did you specify Right-hand or Left-hand, or did I miss that?

If all else fails, there's a firm here in the UK that sells Acme taps of feed-screw sizes to the Model Engineering market, I'd be happy to act as 'go-between'. 
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 09:46:10 AM
Thanks Pete, will try making one before buying -- pretty sure I can get them here, if need be. Right hand, so not too unusual.

I've been playing around with a drawing and one way of cutting the flutes to get a 10 degree angle might be to just offset an end mill from center and cutting to a specific depth -- at least it works out on "paper."

In this case, bring the edge of the mill in .155 from center, then mill to .293 depth. That should yield 10 degrees tap rake angle:

(Interestingly, the .293 depth determines the rake angle, the .155 just determines how much clearance you get -- I just guessed .094" might be enough for the tooth depth. Tapering the end of the tap just reduces clearance, but doesn't alter the tap rake angle  -- it is determined throughout by that .293 cut.)

There is no backed off relief in any of this -- hoping it will work well enough wihout it -- fingers crossed....

Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 12:46:25 PM
Cutting:

(http://vtsteam.com/Lathe/AcmeTap1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 12:48:02 PM
Fluted and stub squared:

(http://vtsteam.com/Lathe/AcmeTap2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 12:49:22 PM
Case hardened and tempered:

(http://vtsteam.com/Lathe/AcmeTap3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 12:51:10 PM
Test cutting some chewey aluminum scrap:

(http://vtsteam.com/Lathe/AcmeTap4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 12:52:52 PM
It works!  :thumbup:

(http://vtsteam.com/Lathe/AcmeTap7.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on May 07, 2015, 01:34:17 PM
Excellent Steve - and the zinc alloy should tap (hopefully) even better. What sort of finish did it leave on the aluminium?
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 02:13:58 PM
Okay, Andrew, but not as nice as the zinc. I just tapped a leftover zinc mini-muffin ingot from last pour to see what the thread looks like - here's a close-up:

(http://vtsteam.com/Lathe/AcmeTap8.jpg)

And the fit on the rod is pretty darn close. probably because a section of the rod was used to cut the thread. When I screwed one of the three foot rods in, it has only about a quarter inch of side play at the far end with the ingot clamped in the vise. Almost no play at all. But it's also an easy smooth turning fit. Basically it's a custom made thread to the rod.
Title: Re: Building a New Lathe
Post by: PekkaNF on May 07, 2015, 03:43:08 PM
Looking good.

The way you did the "rake" looks good, I startted think of it and I think that if you make "hook" it will change effective shape of the cut. Me thinks. :scratch:

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2015, 05:06:23 PM
Not sure what you mean Pekka.  No matter what shape the flutes, the screw can only make its own shape in another solid. A different shape flute relief will affect the ease of cut, only.

Commercial taps have radiussed relief cuts mainly to reduce notch sensitivity I believe, so the tap will break less easily.
Title: Re: Building a New Lathe
Post by: modeldozer on May 08, 2015, 04:29:10 AM
Well done.  Filed away for in case.  :clap: :clap:

 :beer:
Abraham
Title: Re: Building a New Lathe
Post by: PekkaNF on May 08, 2015, 04:44:11 AM
Not sure what you mean Pekka.  No matter what shape the flutes, the screw can only make its own shape in another solid. A different shape flute relief will affect the ease of cut, only.

Commercial taps have radiussed relief cuts mainly to reduce notch sensitivity I believe, so the tap will break less easily.

You are right. I was too tired when I was thinkking of this...like helix angle + side clearances and projections. Like gear cutter.

Any change of a separate how-to-thread with a little text and few picures on how you did that tap. I am specially interested on case hardening. There used to be many chemicals awailable here, but most seems to be either forbiten on unobntanium for hobbyist.

Pekka
Title: Re: Building a New Lathe
Post by: Will_D on May 08, 2015, 05:14:15 AM
Will, In this case I need to tap the casting.
My idea was more along the lines of:

Take a silicon rubber mould off of the thread.

Fill this with investment, remove silicon. Use the male invetsment as a core for the cast bronze.

Or similar using a lost wax master of the leadscrew.

Only trouble may be shrinkage!
Title: Re: Building a New Lathe
Post by: vtsteam on May 08, 2015, 03:51:11 PM
Thanks Abraham, Pekka, Will!  :beer: :beer: :beer:

Pekka, I used Kasenit to case harden the tap. I have a can of it bought a dozen years ago. I don't know if it's still available. Lookups on the net aren't showing it other than providing references to alternative products, or case hardening discussions.

Will, I meant I had to tap a hole in the carriage casting itself, rather than produce a separate leadscrew nut for the carriage. That's why I needed a tap.

Your method seems to imply making a new small part (like a leaadscrew nut), and so it's definitely possible to core a thread in that kind of thing. The Gingery lathe I built has such a casting -- the split nut.
Title: Re: Building a New Lathe
Post by: S. Heslop on May 08, 2015, 05:50:20 PM
Last week I was looking up the prices of acme/ trapezoidal taps and got a fright. I then proceeded to try find information on making taps and found nothing but garbage. So this stuff is very much appreciated!
Title: Re: Building a New Lathe
Post by: vtsteam on May 08, 2015, 07:28:25 PM
Simon, Pekka, there's a lot of reference online to homemade case hardening compounds. I haven't tried any of them because I already had Kasenit, though I'm very interested in simple materials.

It's hard to sift through all the claims and counterclaims, and I don't want to experiment with the ferro or ferri cyanides based on various sometimes opposing opinions.

And those recipes calling for many hours packed in bone, hoof, horn or leather (and there is disagreement about which is best) sealed in stainless boxes at yellow heat isn't practical for me.

It would be nice to have a tested way of case hardening even light depth that was both safe and quick, and involved available materials. I think Andrew, you once mentioned something along those lines -- can't remember.....

The other way to make a tap is to start with hardenable material like drill rod, then turn the thread, mill the flutes, and harden and temper.
Title: Re: Building a New Lathe
Post by: Jonfb64 on May 09, 2015, 02:54:36 AM
Yesterday while at the Harrogate model show I bought a tin of case hardening compound, the ingredients are as follows

Sodium chloride
Potassium ferro cyanide
Charcoal
Calcium phosphate

I forgot to ask how to use the stuff  :Doh:

Steve that lathe is starting to look really good. Are you going to go for direct drive for the spindle and use a motor vfd  combination?

Jon
Title: Re: Building a New Lathe
Post by: DavidA on May 09, 2015, 06:51:13 AM
VT,

The method we used at work to observe the depth of hardness with steel samples was to grind and polish the piece (say a section cut through a case hardened bar) Then immerse it in NItrol.  A mix of Nitric and Hydrochloric acid.
You could then see the depth to which it had been hardened.

In my job it was vital that I only used the original metal as samples, so I had to ensure there was no case hardening left.

Dave.
Title: Re: Building a New Lathe
Post by: awemawson on May 09, 2015, 07:05:05 AM
In WW11 British Prisoners of War used to successfully case harden mild steel to make wire cutters from nothing more complicated than sugar and a spirit lamp. They were distilling hooche and used the resultant neat alcohol on a cotton wad wick, blowing through the flame with a tube rolled from tin plate cut from 'Klim Tins' (dried milk tins).

The steel was heated to a bright red in the improvised blow lamp, then dipped in sugar which carbonised and formed a crust. It was then reheated for several minutes for the carbon to penetrate the surface to get a decent depth of case, then plunged into water. This made a glass hard case and the remnants of the carbonised sugar flaked off.

It just shows that if the needs must ..... simple processes get results !
Title: Re: Building a New Lathe
Post by: NormanV on May 09, 2015, 09:39:38 AM
I tried to case harden some steel using sugar, I'd never heard of anyone else using it. Sugar is carbon rich so I thought that there might be a chance that it would work but it didn't for me. The reheating might be the answer, I will try it.
Title: Re: Building a New Lathe
Post by: vtsteam on May 09, 2015, 10:16:00 AM
Thanks guys. I think this is an interesting enough subject to many of us that I'm going to start a separate Mod-Up, with the purpose of finding and trying useful DIY case hardening materials and methods. No prizes (other than possibly useful information) and I don't think it makes sense to have a vote or winner, but just for fun experimenting, with maybe some benefit from the results.

Also disproving any myths, answering arguments over what works and doesn't, and what is better or worse. My guess is that we'll find that method is at least as important as ingredients. Give me a few minutes to set that up......


Okay, here it is:

http://madmodder.net/index.php?topic=10681
Title: Re: Building a New Lathe
Post by: Manxmodder on May 09, 2015, 02:06:49 PM
I tried to case harden some steel using sugar, I'd never heard of anyone else using it. Sugar is carbon rich so I thought that there might be a chance that it would work but it didn't for me. The reheating might be the answer, I will try it.

Norman,sugar does work quite well. No matter what the carbon rich source is the reheat/heat soak phase is important as it allows time for the carbonising layer to penetrate to a greater depth and build in thickness.

For convenience I do use Kasenit compound fairly frequently,but other carbon sources like charcoal and soot will also work. I have also seen steel hardened with a sooty carburising flame from an oxy-acetylene torch......OZ.
Title: Re: Building a New Lathe
Post by: vtsteam on May 11, 2015, 06:05:40 PM
Cross slide casting. That was a tough one, too. Parting line was part way up the sides so false cope again, and that long thin extension way up in the cope. Messed up the draw twice and had to remake it. I should have made it a loose piece, but didn't. The crucible was absolutely brim full, but I managed without a spill. I thought it might pour short because I had a big riser to fill. Definitely thought I might be doing this one over.... but it poured perfect to the top with no leftover for ingots, and the casting came out fine. So no complaints here! On we go....

(http://vtsteam.com/Lathe/CrossSlide1.jpg)

(http://vtsteam.com/Lathe/CrossSlide2.jpg)
Title: Re: Building a New Lathe
Post by: Joe d on May 11, 2015, 06:21:22 PM
Well. that one came out looking good.  Like the one before it.  And the one before that....

think you've got this casting stuff down, Steve :bow: :bow:

Joe
Title: Re: Building a New Lathe
Post by: vtsteam on May 12, 2015, 05:03:50 PM
Thank you kindly Joe!  :beer:

I miled the top and the slides and rails on the bottom of the cross slide casting. And here's the ball handle I'll be using, which I cast earlier in brass. I didn't set a core in it, so the core print was cast, too, since the pattern had prints. I'll just saw it off and drill.

Tomorrow I'll start on the bottom slide retainers, gib and gib screws. I have meetings from 12:30 on until 6:00 so not sure how much I'll be able to get done.

(http://vtsteam.com/Lathe/CrossSlide3.jpg)
Title: Re: Building a New Lathe
Post by: tom osselton on May 12, 2015, 05:13:02 PM
Another good one! I haven't done any casting yet this year and still haven't tryed a false cope. I use a homemade 5 1/2 "square steel crucible 9" deep  for aluminum so its a little harder not to have enough metal. I use the clay graphite so far for brass and will hopefully give cast iron a go.
Title: Re: Building a New Lathe
Post by: vtsteam on May 12, 2015, 07:16:10 PM
Tom what kind of furnace for the iron? I do remember your first aluminum castings were perfect.  :thumbup:

The cross slide is an inch thick and weighs 10 lbs and the metal for that, the heavy sprue and riser truly filled the crucible. It was cast in Zamak again. I decided to use that for anything that has linear slide on this lathe, since it has really nice bearing qualities on steel.

I've been using a clay graphite crucible for the zinc alloy, a new one I bought, originally advertised for iron, but others of the type deteriorated quickly for that purpose so I had shelved this one, new. It is is fine at lower temperatiures for zinc however, and is in perfect shape after three pours.

For small brass crucible so far, I use a small cast iron plumber's pot lined with fireclay and sand mix.

Looking forward to seeing more of your casting! :beer:
Title: Re: Building a New Lathe
Post by: Meldonmech on May 13, 2015, 12:28:30 PM

  Steve, they are fine castings, I have only used a loose piece on a pattern once, but it was quite successful. The brass handle has come out well, did you make a pattern or use a modified original with the hole plugged?  I have now relined my furnace with 1600 degree C refractory, and am building up to a brass melt, just need a crucible. I did have a nice cast iron plumbers pot, but accidentally melted it during an aluminium melt. At least it proves the heat is there. I have quite an amount of scrap brass which is chromium plated, have you ever removed this from any of your scrap, if so how?

                                                                   Cheers David
Title: Re: Building a New Lathe
Post by: Andrew Wildman on May 13, 2015, 01:04:03 PM
not much to add - other than to say that I am enjoying the build.  One of the most practical and well thought out home built lathes I have seen.

Like the use of the Zamac material.  Looks like it could be very useful for a number of different applications. :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on May 13, 2015, 04:36:57 PM

  Steve, they are fine castings, I have only used a loose piece on a pattern once, but it was quite successful. The brass handle has come out well, did you make a pattern or use a modified original with the hole plugged?


I made a wooden pattern, David, quite a long time ago -- might have even been the first casting I did (aluminum version) for the Gingery lathe 14 years ago. Normally the core is a piece of steel rod, blacked with soot of a candle so it can be knocked out of the casting to leave a perfect fitting hole.

(http://vtsteam.com/Lathe/BallPattern.jpg)

Quote
I have now relined my furnace with 1600 degree C refractory, and am building up to a brass melt, just need a crucible. I did have a nice cast iron plumbers pot, but accidentally melted it during an aluminium melt.


WOW! that was hot!

Quote
At least it proves the heat is there.

I guess so!

Quote
I have quite an amount of scrap brass which is chromium plated, have you ever removed this from any of your scrap, if so how?

David, I've never removed it from brass. I have removed it from pot metal (diecast zinc) simply by melting the zinc out. Chromium has a pretty high melting point, and zinc quite a low one, so it wasn't difficult to separate the two on a small scale. The diecast metal puddled out of the plating which remained as a thin skin and was separated out with a slotted spoon.

I believe chromium vapor is hazardous, so one wouldn't want to melt that, but as I say, the difference in melting temp was great. I don't know about brass and how much leeway there is for the chrome. Might be do-able but you'd have to study up on temps and exercise more care. If your furnace melted a cast iron pot during an aluminum melt it sounds like you have a monster burner -- might be a consideration.
Title: Re: Building a New Lathe
Post by: vtsteam on May 13, 2015, 04:40:37 PM
Thanks kindly Anrew W. !!  :beer:
Title: Re: Building a New Lathe
Post by: tom osselton on May 13, 2015, 05:33:35 PM
Tom what kind of furnace for the iron? I do remember your first aluminum castings were perfect. 

I will try it with my forced air, propane/fiberwool furnace so it will be interesting to see if the blower will give enough air its ok with brass plus there is always the shopvac as backup.
I have to admit I have had good luck with my casting so far mostly using dad's patterns or 3d printed ones. I have been increasing my woodworking tools to get more into patternmaking and should get a better pair of gloves for the higher heat.
Title: Re: Building a New Lathe
Post by: vtsteam on May 13, 2015, 09:26:50 PM
Well, let us see how it goes with iron when you get to it. It was quite a learning curve for me. I haven't cast iron yet this year as conditions are not yet right -- first too wet in the spring, now too dry -- the whole state is presently under an outdoor burning ban.

It's funny, I started out this project thinking I was going to do most of the major pieces by fabrication in steel, but have ended up casting all but the bed.

I might just switch back to steel in doing the headstock. It's not a sliding component, except for initially boring the bearing recesses, and I'm running low on zamak. I don't favor aluminum here -- steel will give me more rigidity and mass in the same thicknesses, and I definitely want that in the headstock. Cast Iron is still not do-able for the above fire reasons. So steel might be the best choice.

Zamak has worked well for castings, but is difficult to work with -- especially with hand tools. Filing practically doesn't work -- it is both hard and slippery, and a file tends to skid across the surface, and won't bite in. It clogs grinding wheels, unlike iron or steel.

I would NOT recommend zamak castings to anyone building a first lathe like the Gingery. Or anyone who didn't own a milling machine to work it. I think aluminum is ideal for the Gingery lathe (except fof the half nut, which should be zinc alloy for wear resistance and bearing qualities). Dave Gingery suggested either alloy would work, but I think zinc alloy would be torture for a beginner with only a set of files and a homemade scraper. I doubt the lathe would be finished after a difficult start.
Title: Re: Building a New Lathe
Post by: mattinker on May 14, 2015, 05:41:01 AM
Steve,
I would NOT recommend zamak castings to anyone building a first lathe like the Gingery. Or anyone who didn't own a milling machine to work it. I think aluminum is ideal for the Gingery lathe (except fof the half nut, which should be zinc alloy for wear resistance and bearing qualities). Dave Gingery suggested either alloy would work, but I think zinc alloy would be torture for a beginner with only a set of files and a homemade scraper. I doubt the lathe would be finished after a difficult start.

I f I remember correctly, you are using ZA2? Zamak comes in several varieties, I made ZA12, which has 10% more Al (by weight) in it, which should be easier to file etc. I have never made ZA2 so I cant compare!

Regards, Matthew
Title: Re: Building a New Lathe
Post by: vtsteam on May 14, 2015, 07:45:07 AM
That could be a difference Matt, haven't tried ZA-12. I chose ZA-2 for a different project and its good bearing qualities, Maybe what makes it a good bearing (wear resistance, slipperiness) is what makes it challenging to file. I'll have to try za-12. Have used ZA-3 as well.
Title: Re: Building a New Lathe
Post by: Brass_Machine on May 14, 2015, 02:33:12 PM
...

Tomorrow I'll start on the bottom slide retainers, gib and gib screws. I have meetings from 12:30 on until 6:00 so not sure how much I'll be able to get done.

...

Sounds like the type of days I have... we work for the same company?  :lol:
Title: Re: Building a New Lathe
Post by: vtsteam on May 14, 2015, 02:56:18 PM
Volunteer work Eric -- training for teaching the next section of natural science demos in school (once a month), and then right after, school district union finance committee meeting in the next town.

Fabulous day outside today, trees leafed out flowers everywhere, makes the winter worthwhile!

Not getting much done on the lathe again -- too nice to go into my blockhouse shed!
Title: Re: Building a New Lathe
Post by: awemawson on May 14, 2015, 03:56:04 PM
I know that feeling Steve - I seem to have only a passing acquaintance with my workshop these days  :bang: Amazing how much time bottle feeding lambs can take up, but the spring springing all around makes it worth while  with thing bursting into life and at last the grass growing.

One possible benefit of this lack of time (but no doubt it'll cost me an arm and a leg) - I packed the digger with the hydraulic leaks off to a commercial transport garage to fix today. The 360 degree rotary coupling between the track base and cab assembly is the cause and needs pulling and new seals fitting, a friend offered the use of his HUGE John Deere tractor and flat bed plant trailer to get it there and while there they are replacing all (ten) track rollers and welding up the dozer blade for me. We caused a major traffic hold up in Rye when we got there in convoy  :lol: I'd given myself significant back ache crawling under doing the diagnosis so it's probably worth getting someone else to work on it. Anyway they have the right kit. It went straight onto a massive lorry lift, and was floated up in the air effortlessly - so much for aches and pains  :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on May 14, 2015, 10:41:37 PM
It will be nice to get it back in working order Andrew instead of making it another project when you've got five more on your mind! I think that was a good decision -- would have been frustrating otherwise.

More goldbricking for me tomorrow -- we teaching volunteers are invited upstate to a walk in the woods, nature drawing lessons, and other fun stuff plus lunch as an end-of-school year thank you, so I'm carpooling up there and won't get back til afternoon.

I think I'll be raring to get back on the lathe by Saturday. I need to put the bottom slide retainers on, and fit the gib and gib screws.

I've been looking at 3 jaw chucks on ebay. Can't afford anything fancy. Undecided whether it ought to be 4" 5" or 6" on the lathe -- lathe capacity is 9". The present cross slide might just by a hair fit under a 5" chuck. Not sure if it will. Certainly wouldn't clear the jaws if they protruded.

It isn't absolutely essential that a cross slide fit under the chuck, but I think it might prove handy some time. The 4" would surely do it. The 6" is thicker which reduces the bed length capacity, and adds to overhang and the possibility of chatter. It would be nice to have a 6" for capacity, but I think the turning drawbacks might be regretted later.

I'm thinking 5" probably....
Title: Re: Building a New Lathe
Post by: vtsteam on May 16, 2015, 10:26:45 PM
I have the retainers made up, drilled, countersunk, the carriage drilled and tapped. Put it all together with the need for only a single  ,001" brass shim on one side (normally I shoot for two on each side to allow adjusting down the road for wear).

But at supper time the carriage was still a little tight, so I'll need to adjust things tomorrow. I might have to give a little more relief in the carriage sides  for the retainers, because I think one of them is just touching on one side. And maybe add another shim. Then I need to make a gib. I sent for some socket head screws to use as gib screws.

I ordered a 5" 3 jaw plain back chuck.

I'll be making a backing plate. I'm thinking of recessing in it the entire spindle flange, not just the spindle flange register. That would shift the backing plate back and reduce overhang, and if it's a shrink fit, I think it might be stronger than just the bolts alone. It would just look like a bigger flange on the spindle.

I do regret that I didn't look more carefully at the mini-lathe spindles before I bought one -- I didn't think about the fact that they don't have a screw mount, but have bolt mounts instead. I guess it's more involved changing chucks as a result.

I was curious to see if there were any backing plate adapters for mini-lathe spindles that had a male threaded section for using threaded back chucks, but they don't seem to exist.
Title: Re: Building a New Lathe
Post by: vtsteam on May 17, 2015, 09:39:42 PM
Cross slide is working smoothly now, but I don't have gib screws for it yet.

I spent some time today trying to decide what to about the cross slide upper surface. I thought about tee-slots but I didn't like the thought of weakening the nice 3/4" thick surface I have now. If it was an inch thick to start with, I might have milled the slots in.

I could add more metal and fabricate tee slots that way, as I did for the Craftsman boring table I made a couple summers ago. But that raises the table itself, so you can't do as much with it.

I'm considering just drilling the top with a regular grid of tapped holes. Those leave the table much stronger than tee slots, and it gives me a big flat surface to mount things on as well as keeping the table lower.

I'm also thinking carefully about what kind of tool post I want. I already have both lantern style and a round post Norman QCTP with toolholders made up for both the Craftsman and Gingery lathes, so it would be logical to go with that QCTP.  style.

But I've long wanted to try out the style of tool holders and system written about by Robert M Rose in M.E (Nov 1972: 3452, 3453, setting Aug 1972: 3446). These are just simple tall blocks that clamp directly onto the cross slide (or top slide) no dovetailed QC tool holder or round post and block holders.

I like the simplicity and flexibility of positioning, and the fact that they do a better job of supporting the tool than the post and block type can, yet take up little space and are easily removed for other kinds of table operations

Another advantage I see in trying to figure the geometry of where to mount things along the cross slide-- It is easier to move these toolholders anywhere along the table to keep the cross slide clear of wide diameter work. I like the design of the base of the toolholder resting directy on the cross slide when the topslide is not needed. There is total support with no bending force on a post.

Much of what I've done in designing this lathe is to increase the rigidity and support of every part, and I think these toolholders will advance that philosophy. They are slightly less convenient than the usual types of QCTP, but for a small lathe like this I think they have the advantage of minimal overhang and solid bearing. A larger lathe can feature a massive enough QCTP that rigidity is not an issue, but I believe a small lathe like this can see a benefit.

Another nice thing about both the grid holed table, and the Rose style toolholders is that both are even easier to make than the usual types we see these days.
Title: Re: Building a New Lathe
Post by: PekkaNF on May 17, 2015, 11:48:16 PM
Toolpost rigidy is an issue and I noticed huge difference when I replaced the topslide with a sandwich block. I made two screw holes to mount QC toolholder to two different locations, other location allows tool well towards the tailstock (for boring and max diameter turning) and the other to bring the tool tip to front shear and right over cross slide way for maximaal stiffness. I had before huge problems with parting off, now motor power is more of an issue than toolholder/post.

Pekka
Title: Re: Building a New Lathe
Post by: awemawson on May 18, 2015, 03:02:25 AM
Steve,
A matrix of holes is very versatile in that you can mount sub-tables with t slots or special fixing as you wish..
It also keeps a degree of 'post design design' letting you change your mind as the project develops
Title: Re: Building a New Lathe
Post by: vtsteam on May 18, 2015, 09:33:00 PM
Thanks Pekka, Andrew  :beer:!

Andrew making bolt-on upper tables eg. T-slot type is something I hadn't thought of! That might come in very handy for a few things I've been mulling over.

For instance, I'd like to maintain the maximum vertical distance between the cross slide and the lathe center in order to be able to bore pieces that are fixed to the slide, using a fly cutter on an arbor mounted between centers. Looks like I have 2.5" + distance for that, now.

But for lathe tool holders clamped to the table (as in the Rose system mentioned earlier) 2.5" is excessive for the tool holder height. I'd rather they were say 1.5" maximum. If I bolt a short 1" thick auxiliary table to the carriage top, I can now reduce that distance by an inch, and also gain the advantage of T-slots for positioning the clamp.

Likewise I could make an auxiliary table with large round recess to take the foot of the topslide ways, so it can be rotated.  Normally that would be a recess cut into the cross slide, again, reducing stiffness -- so the cross slide normally must be heavier sectioned to accomodate it.

But with a bolt-on table top, the cross slide/boring table can be thinner (as it is here @ 3/4'), yet stiffer than a thicker section with a recess, plus the bolt-on topslide fixed base adds to it instead of subtracts from its thickness.

I like it! Thanks Andrew :bow:
Title: Re: Building a New Lathe
Post by: vtsteam on May 19, 2015, 05:37:10 PM
I drilled and tapped the cross slide for gib screws today, made up the cross slide gib, and installed some temporary long round head screws. I could then align and lock the cross slide to the carriage. With that in place, I could mark the centerlines for height and and horizontal location of the cross slide leadscrew.

I then pilot and step drilled the leadscrew holes in both cross slide and carriage. This was all done with an electric hand drill by eye while they were mounted on the lathe bed. I spent a lot of time checking with straightedge and square as I was going  for all the drill steps.

Once I'd opened the carriage out to the tap drill size, it was time to bring out the homemade acme tap and start tapping. Again checking frequently with square and straightedge to start with and making corrections to get a good start:

(http://vtsteam.com/Lathe/Carriage6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 19, 2015, 05:44:33 PM
The tap cut beautifully and surely, and I was extremely pleased to see the leadscrew center all the way through the channel, and turn by hand with a slight resistance (no handle) and no feeling of play or backlash. I doubt I could have got a better alignment with a drill press setup, trying to drill the carriage end-on vertically, even if I had enough range on my drill press -- which I didn't! 

A great relief that things all worked as well as I could have wished!!  :ddb:  :beer:

(http://vtsteam.com/Lathe/Carriage7.jpg)
Title: Re: Building a New Lathe
Post by: DMIOM on May 19, 2015, 05:56:54 PM
The tap cut beautifully and surely, and I was extremely pleased to see the leadscrew center all the way through the channel, and turn by hand with a slight resistance (no handle) and no feeling of play or backlash. I doubt I could have got a better alignment with a drill press setup, trying to drill the carriage end-on vertically, even if I had enough range on my drill press -- which I didn't! 

A great relief that things all worked as well as I could have wished!!  :ddb:  :beer:

 :clap:  :clap:  :clap:  :clap:  :clap:  :clap:  :clap:   :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on May 20, 2015, 09:22:10 AM
Thank you Dave.  :beer:

I have to teach today, but hope to get a little more done on the ledscrew after.

Title: Re: Building a New Lathe
Post by: RobWilson on May 20, 2015, 02:23:29 PM
 :clap: :clap: :clap: :clap: Just loving this project Steve  :thumbup: 


Rob
Title: Re: Building a New Lathe
Post by: vtsteam on May 21, 2015, 07:11:59 PM
Thank you Rob! :beer:

Today's bits:

Made use of the core print in the ball handle. I turned it to 7/16" O.D. and drilled and reamed to fit the reduced end of the cross slide lead screw. Then 2 pieces of scrap brass bar were turned, and one drilled and reamed to fit the lead screw, and the other to fit the ball hande shaft. A set screw was put into the ball handle and a flat milled on the leadscrew to match:

(http://vtsteam.com/Lathe/CrossSlideLeadscrew1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 21, 2015, 07:26:34 PM
And putting them together this is pretty much how I think it will go. The inner disk will be the bearing and pointer, screwed to the carriage, and so, stationary. The other disk will be graduated. Leadscrew is 10 tpi, so i need 100 graduations.

I don't have a working dividing head. I do have a 5C spin indexer, but it is divided in degrees, and 100 into 360 isn't a go.

Today it ocurred to me I could probably take the graduated collar off of my mill carriage and rig it onto the lathe spindle, set up a pointer, and then cut the graduations with a tool in the tool holder. The mill dial also has 100 graduations, and it is several times the diameter of the new lathe collar, so it should be reasonably accurate, if I have me glasses on!

(http://vtsteam.com/Lathe/CrossSlideLeadscrew2.jpg)
Title: Re: Building a New Lathe
Post by: Joe d on May 21, 2015, 08:12:01 PM
I like the looks of that one, Steve! :thumbup:

Of course, it's brass.  Brass parts are like puppies, impossible not to like....

Joe
Title: Re: Building a New Lathe
Post by: vtsteam on May 22, 2015, 10:52:57 AM
Thanks Joe!  :beer: I've been hoarding half a nail keg full of scrap brass and bronze odds and ends bought at auction that I've hardly touched in 6 years. I decided lately I'd better stop storing it and start using it, or it wouldn't ever amount to anything but scrap!  :wack:

Thought a little more about simple dividing to 100 divisions, and decided I didn't even need to pull the division ring off the mill handle. Just work up a 100 division circle graphic in Sketchup 7, print it out, and contact cement it to a sheet of aluminum, thin ply, or acrylic. This gives a direct division plate, and it can be screwed to a collar to fit an arbor with a setscrew, or whatever.

Figured someone else here might find it useful, too, so I made a pdf of it, attached below. This prints to a 6" circle if you print from acrobat reader with no scaling and no "fit to page". You can scale it smaller, if need be in Acrobat reader. Or just print it out full size and cut it down with scissors.

6" gives divisions about 3/16" (5mm) wide so it should be possible with a pointer to direct divide by eye reasonably accurately. I'd say to within a tenth of a division or better. (Or in my case, +- .0001" in slide movement -- probably less than the thickness of the engraved line itself on the collar.)
Title: Re: Building a New Lathe
Post by: awemawson on May 22, 2015, 11:28:33 AM
Now if you had a 100 tooth change gear all you'd need would be a detente.

Nice handle and shaft Steve  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on May 22, 2015, 09:06:10 PM
Thanks Andrew!  :beer: No gots on the gear. Drove tractor most of the day mowing and tilling.
Title: Re: Building a New Lathe
Post by: vtsteam on June 02, 2015, 08:13:23 PM
Yesterday I cleared some space under the shed roof extension so I could cast with the propane furnace. Today because it was still raining, I couldn't continue work with the tractor. So back on the lathe!  :thumbup:  I did a quick casting of some stock for some needed bolt-on bearings in ZA-2.

To save metal, greensand and time, I decided to cast it as its own sprue, in a soup can as a flask. No taper on the pattern. I just rapped it as I filled and packed the flask, so it was never too tight. Then I continued rapping as I drewthe pattern out -- very carefully. I had packed the sand quite tightly because as an open mold, it was naturally vented through the top. It left a very good impression in the greensand:

(http://vtsteam.com/Lathe/BearingMold.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 02, 2015, 08:27:04 PM
I overpoured because ZA-2 shrinks quite a lot just before freezing, and there is no sprue or riser to prevent a cavity in the part. This worked and using the method I got a very sharp casting with good clean corners using the tin can. It was very quick to ram up a mold this way, and used about a fifth of the greensand and no sprue. Without draft there is less machining necessary and less allowance needed, also saving time and material. I was very happy with this quick casting today. The part will yield 2 or 3 bearings when sawn into sections:

(http://vtsteam.com/Lathe/BearingCasting.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 04, 2015, 01:06:37 PM
Another casting, this time in copper alloyed aluminum. It will serve as a mount for the stepper motor attached to the shears at the headstock end of the lathe. I used aluminum here because of its good heatsinking properties.

(http://vtsteam.com/Lathe/BedEndPiece.jpg)
Title: Re: Building a New Lathe
Post by: mattinker on June 04, 2015, 02:00:41 PM
Another casting, this time in copper alloyed aluminum. It will serve as a mount for the stepper motor attached to the shears at the headstock end of the lathe. I used aluminum here because of its good heatsinking properties.



You should find that it machines nicely without the "gummyness" of the pure Al.

regards, Matthew
Title: Re: Building a New Lathe
Post by: tom osselton on June 04, 2015, 04:21:37 PM
That is a nice surface on your casting.   :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 04, 2015, 04:37:53 PM
You should find that it machines nicely without the "gummyness" of the pure Al.

regards, Matthew

Yes, it did Matthew. Slightly "crunchy" with very granular swarf that I noticed last time. It still isn't harder than any other aluminum I tried scratching it against, but should be if heat treated (which I won't do), as I discovered last experiment.

(http://vtsteam.com/Lathe/BedEndPiece2.jpg)

Tom, thank you!  :beer: I've been reducing draft down to nothing and getting away with it lately by rapping "artfully". It works in these castings so far. Sand has been just on the borderline of dry for my usual ram up. So I have a lot of cleanup sometimes. But it seems to be working to give very sharp square corners -- really cuts machining alowance down (and machine time, too). I'm liking this!  :headbang:
Title: Re: Building a New Lathe
Post by: vtsteam on June 07, 2015, 09:10:35 PM
I had a little time today to work on the lathe. I driled and tapped the aluminum stepper mount end bracket and temporarily bolted it in place so I could work on the leadscrew and leadscrew bearings.  I'm waiting for arriival of 2-1/2" long socket flat head screws by mail to permanently mount the bracket.

The Acme leadscrew stock was turned down at the ends, and the cast bearings were bored to fit. i clamped them in position to make sure I had the length right, and to check clearance to the carriage, and measure for location the half nut.

That was it for the day.

(http://vtsteam.com/Lathe/LeadscrewBearing.jpg)

(http://vtsteam.com/Lathe/Leadscrew1.jpg)
Title: Re: Building a New Lathe
Post by: RobWilson on June 08, 2015, 02:42:27 PM
Loooookin mighty fine Steve

Your castings do turn out well  :clap: :clap: :clap:  , I have some ally casting to do later this month  :ddb: 


Rob
Title: Re: Building a New Lathe
Post by: mexican jon on June 08, 2015, 05:52:24 PM
I had a little time today to work on the lathe. I driled and tapped the aluminum stepper mount end bracket and temporarily bolted it in place so I could work on the leadscrew and leadscrew bearings.  I'm waiting for arriival of 2-1/2" long socket flat head screws by mail to permanently mount the bracket.

The Acme leadscrew stock was turned down at the ends, and the cast bearings were bored to fit. i clamped them in position to make sure I had the length right, and to check clearance to the carriage, and measure for location the half nut.

That was it for the day.

(http://i786.photobucket.com/albums/yy150/vtsr/vtsr/Shop/LeadscrewBearing.jpg)

(http://i786.photobucket.com/albums/yy150/vtsr/vtsr/Shop/Leadscrew1.jpg)

I'm loving this thread  :thumbup: I get a little disappointed when I sign in and there isn't an update to read  :( Keep up the great posts and the excellent build  :bow: :bow:

P.s. Do you not think your clamps need a little bit of the love and care that is being lavished on the lathe  :lol: :lol: :lol:
Title: Re: Building a New Lathe
Post by: vtsteam on June 08, 2015, 06:15:37 PM
Thanks Rob! :beer:  You're going to be happy as a clam (as my New Orleans grandmother used to say) casting again!  :thumbup: :clap:

Jon thanks kindly, :beer: I hate to put it off, too -- it's not like the winter anymore and so many things I need to do before the next bout of cold weather, but I'm going to try to work on the lathe a little every other day between chores. Half nut looks to be the next needed part on the lathe.

Haha, agree totally about those clamps, poor things. I remember buying 20 of them for $1.50 each in 1972 when I was building a 27' catamarran to sail the coast in. Never did finish that boat, but I still have the clamps. They've been everywhere, including the bilges of the houseboat, holding things tgether in the rain. They're covered in not just rust but that and layers of epoxy, etc. You're right, they deserve better. Maybe one day the'll get dunked in washing soda, electrified, re painted and oiled -- straightened where necessary, too. But they still work well, have a deeper reach all around than my nicer cast iron C clamps, so they suffer everywhere......terrible case of tool abuse.  :whip:
Title: Re: Building a New Lathe
Post by: S. Heslop on June 08, 2015, 07:43:11 PM
It's already looking real professional and sturdy. Can't wait to see what you've got planned for the headstock.
Title: Re: Building a New Lathe
Post by: vtsteam on June 08, 2015, 10:24:35 PM
Simon, I have a "sorta kinda" idea in mind for the headstock but it will probably boil down to just working it out in PineCad 3D.

In other words putting pieces of scrap wood together right on the ways to see what is going to fit, accept the wings of the carriage without interference, cover the stepper bracket,  at the right height, accept the roller bearings, room for pulleys, and with slides, and look beefy enough, etc. That will then be the pattern.

Not sure if I will cast it in zinc or iron -- kinda depends on how much metal it will take (limited iron crucibe capacity) and whether all my iron gear is in shape. My iron sand got waterlogged and I have been spreading it out on plastic sheet in the sun trying to dry it out.

But, I gotta do the half-nut first so I can get the carriage working on the leadscrew. No point casting the headstock until I have the means to bore it..
Title: Re: Building a New Lathe
Post by: PekkaNF on June 09, 2015, 01:49:57 AM
Simon, I have a "sorta kinda" idea in mind for the headstock but it will probably boil down to just working it out in PineCad 3D.
:lol: that was very good!


Not sure if I will cast it in zinc or iron -- kinda depends on how much metal it will take (limited iron crucibe capacity) and whether all my iron gear is in shape. My iron sand got waterlogged and I have been spreading it out on plastic sheet in the sun trying to dry it out.

My first lathe had a headstock/tailstock and all but bed made out of "special alloy". Alloy and plastics on all the wrong places. Some ideas were fine and finish was good but 1/4 of the elastic module of the steel and 1/4 of the quality lathe.

Pekka


Title: Re: Building a New Lathe
Post by: vtsteam on June 09, 2015, 09:14:19 AM
To be honest, Pekka, the zinc alloy would probably have higher properties and be better for the purpose than cast iron. Check the properties for za-12, including tensile strength and damping. If I cast it in iron, it would be more a matter of using my big furnace and melting iron once again for the fun of it -- and coming full circle in using so many different fabrication methods and materials on this one project.

The problem with most commercial die cast zinc alloy products is that the material and method were chosen to minimize cost, by using very thin sections and high speed production methods. Zinc alloys are so strong and easiy injection molded into thin webs that such are the norm. It's possible to find machine tools with 2 mm sections and complex webbing in ZA because it can be formed and used this way. You'd never be able to do that in iron, it doesn't have the tensile strength or easy injection molding capability.

ZA cost saving is not a priority in a home-shop built small lathe -- I'm only making one, and it's easier to just cast a thick section than a thin web. The cross slide on my lathe is 25mm thick ZA by comparison. It's stronger, stiffer, and more vibration absorptive than an equivalent thickness cast iron, part -- both are overkill, however, because of the need to be able to bolt accessories to the table through either Tee slots or tapped holes. So it doesn't really matter from a design standpoint, the thickness is determined by practical fastener depth requirements.

For the headstock, I'd say ZA has the edge, because of tensile strength requirements around the area of the bearing housings, and in general torsion on the whole at the center height for cutting and the pull of the drive belts, plus vibration damping qualities, re chatter. I'm sure both will produce good headstocks if properly sectioned, but if i were just to stack up materials properties for the same headstock sections, I'd say ZA would be better.
Title: Re: Building a New Lathe
Post by: PekkaNF on June 09, 2015, 03:43:06 PM
I have packed that lathe away to resist selling it to anyone, because it is that bad.

I have become so allergic to any zink alloys that it might influence on my views, but that lathe is soo bad. Maybe I should take head stock away and take some photos. The casting don't look even as thick than economy cast iron. If it were solid it might have fared better.

Also slides were this wonderfull zink alloy.

I don't think that ultimate strenghth is issue here, but I wish it were more rigid. Turning iron metals with it was like trying to peel rotating wiener with a carrot. Turning tool had to be razor sharp or piece was escaping at front of it. Like everything was flexing.

Wish they would have had sense to build it right, it might have worked better.

That said,  you don't need to wring out every gram of it and cut all the corners, therefore I believe you are going to succeed.

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on June 09, 2015, 09:36:59 PM
Well Pekka, this is new territory for me, too. Maybe I won't like the zinc for some reason or other, down the road. In which case I'll just replace the part with another one in iron, or whatever. That's the nice bit about being your own manufacturer, customer, and customer service department! No arguments.

I did have only one part in zinc alloy on the Gingery lathe. I lookied at it about a month ago and it appeared as good as it was when cast 13 years ago. And a very high wear part at that: the half nut.

It's amazing how tough that has been. I see more wear on the steel ways and slides than on that half nut. I wonder how many miles of leadscrew thread have passed through it? And sometimes at pretty high pressure, with swarf. That toughness is one of the things that impressed me and got me thinking about using some alloy on this newer lathe. We'll see how it works out in practice.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 13, 2015, 05:11:09 PM
Waiting a couple days for a call back from the sand and stone delivery guy, so at a halt on th4e cistern, so back on the lathe!

I made a pattern and cast the half nut using a piece of threaded rod smoked with a candle as a core, and casting in a steel arbor.

(http://vtsteam.com/Lathe/Halfnut1.jpg)
Title: Re: Building a New Lathe
Post by: mattinker on June 13, 2015, 05:14:21 PM
Looking good Steve, the ZA alloys are great!

Regards, Matthew
Title: Re: Building a New Lathe
Post by: vtsteam on June 13, 2015, 05:15:57 PM
Zinc and sand eat end mills, and the only carbide ones I have are too big for this, so it was mostly hacksaw chisel and file for this one, though I did have a carbide lathe tool to turn the rim. Anyway, here's the nut cleaned up some. The core left the thread prints.

(http://vtsteam.com/Lathe/Halfnut2.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on June 13, 2015, 05:59:55 PM
Thanks Matt!  :beer:

And trial fit to the leadscrew -- it works!  Holding itself up here because the fit is very close since it was cast on the actual screw core rather than tapped.

(http://vtsteam.com/Lathe/Halfnut3.jpg)
Title: Re: Building a New Lathe
Post by: Meldonmech on June 14, 2015, 06:39:11 AM
Hi Steve,

                   The nut turned out well, I have never had the need to use a smoked steel core, but will give a go next time I am casting. Was the core difficult to remove?

                                                                           Cheers David
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 08:23:27 AM
Yes David, It was fairly difficult to remove because it was well locked in by parts of the casting that had to be removed themselves, and it was zinc. But not because the casting adhered to the core. Once freed of the temporary fillets, it popped right out when tapped with a drift. But chopping away the zinc with a chisel was slow going, and it was difficult to get a grip on this particular part in a vise that could take a good hammer blow on the chisel.

There are quite a few smoked steel cores in the construction of a Gingery lathe, as well as permanently affixed arbors (no smoke) as in this one. This design half-nut is basically the same as used on the Gingery lathe, with a change in dimensions, and the use of a much coarser acme thread and bigger leadscrew. I did wonder how that might work out. But it has very well here.

A steel core can be removed when the bury is up to about an inch, when driving out lengthwise for a full hole, at least in aluminum. it gets harder to do above that length. The resulting fit is always very close.

A half section, as in a split bearing half, is much easier to remove, and a half casting like that is essential on a threaded piece for removal ...I would think. I've never tried to unscrew a full cast thread. Maybe it could be done....don't know.
Title: Re: Building a New Lathe
Post by: PekkaNF on June 14, 2015, 02:02:25 PM
That looks pretty good (and sounds a little laborous).

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 02:53:23 PM
Thnks Pekka! :beer: Maybe it sounds worse than it was -- I probably spent an hour on it.

Today I made a feed lever from a piece of scrap stainless and brass. The half-nut opens and closes. I just need to make a spring loaded detent to complete the carriage.

(http://vtsteam.com/Lathe/FeedLever1.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on June 14, 2015, 03:03:29 PM
Looks really good Steve  :thumbup:

Don't let it get wet, that zinc and brass will fizz away and produce a nice (not so little) battery  :bugeye:
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 03:21:19 PM
Nah, salt not fresh water! And I promise not to dunk it in the ocean.  :lol:

Or a lake for that matter. Aluminum and brass or bronze, bronze and steel, aluminum and steel, stainless and bronze all form galvanic couples in salt water, and yet are routinely used in combination on all kinds of equipment. And equipment a lot more exposed to the elements than this lathe will ever be.

Anybody out there using aluminum bolts for even your all aluminum projects? Even aircraft routinely mount aluminum with steel AN fastenings.
Title: Re: Building a New Lathe
Post by: awemawson on June 14, 2015, 03:27:08 PM
No salt in your perspiration then?
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 03:30:44 PM
Andrew you can't be serious!

You really think a couple of brass handles and perspiration are going to seriously degrade this lathe......in how many years do you figure -- so I know when to start another one?
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 03:37:23 PM
Of course there's an even better reason not to get a lathe wet. And it doesn't even need a galvanic couple....the ferrous parts rust.

Of course we all try to prevent that with this other substance called oil. Works on brass and alloys too.
Title: Re: Building a New Lathe
Post by: mattinker on June 14, 2015, 03:48:41 PM
Anyway, it looks very nice! Sort of maritime!

Regards, Matthew
Title: Re: Building a New Lathe
Post by: awemawson on June 14, 2015, 03:51:10 PM
loosen up Steve, it was a joke  :thumbup:

But you know, there are some engineers who know that they have 'rusty hands' and I'm sure it's that they perspire more salt.
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 03:59:06 PM
Heh, you did get me going Andrew -- the idea that it would "fizz" away like a big battery if wet didn't uhhhhh hold water, so in humorous spirit then back at ya, don't sweat it! :lol:

As you know  brass IS zinc and copper combined, and gets wet without fizzing away, and likely won't mind keeping company with zinc as much as some other metals it's routinely mounted on.
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 04:22:34 PM
Anyway, it looks very nice! Sort of maritime!

Regards, Matthew

Thanks Matt!  :beer:

That reminded me of a marine steam engine I have -- over 60 years old -- of brass and aluminum construction. Between steam and water, it definitely was wet for a lot of its useful life, and since it was built in Baltimore, might even have seen salt water. It's a beauty and proud posession, in very good shape, and still runs:

(http://vtsteam.com/Lathe/steamtwin.jpg)
Title: Re: Building a New Lathe
Post by: RobWilson on June 14, 2015, 04:38:15 PM
That's a Canny wee engine you have there Steve  :thumbup:

Lathes looks like its coming on a treat  :clap: :clap: :clap: :clap:

Rob
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 04:59:30 PM
Thanks Rob!  :beer: :beer: It's a pretty good sized engine, Rob, bigger than it looks in the picture -- one of two that I bought about ten years ago at a model engineering show at the Precision Museum in Windsor, VT. Very similar engines are mentioned in an old Model Engineer, built by Arthur M. Balling of Balimore (issue 3308), and I'm certain this one was built by him. The seller did mention Baltimore, also. You can see the raw sand casting in some areas --n he built a big series of these as experiments to test out different valve gear.

Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2015, 11:02:20 PM
Tonight I spent a couple hours out in the workshop, and made the halfnut detent arm and spring, and filed grooves on the halfnut rim to accept them. I shaped everything until I liked the feel of the snaps, both engaged and disengaged.

I found I had a little play in the half nut engagement with the leadscrew, yielding backlash, because it wasn't quite thick enough to contact the back of the apron, by .024", measured with a feeler gauge. It was cocking slightly with a change in direction. It is supposed to bear against the apron, so I made up a shim washer that thickness, and then there was no more play at all. The backlash disappeared.

Everything was a little stiff, so I chucked an electric drill onto the tailstock end of the leadscrew and moved the carriage end to end 20 times times to wear the halfnut in a little. Then I checked again the position of the engagement detent to adjust if necessary, but it was fine. The carriage moves smoothly now, the halfnut stays engaged, and clears when disengaged.

I moved the carriage near each end in turn and adjusted the leadscrew bearings up or down to eliminate any bow when engageing the half nut. I haven't drilled for the bearing mounting bolts yet, but they now are both correct in height and clamped, ready for drilling. I might slot them anyway so they can be adjusted up or down if needed.
Title: Re: Building a New Lathe
Post by: awemawson on June 15, 2015, 02:44:01 AM
Steve I'd be tempted to slot them and when I was sure that the adjustment was spot on, drill and ream for a roll pin.
Title: Re: Building a New Lathe
Post by: RobWilson on June 15, 2015, 04:37:53 AM
Thanks Rob!  :beer: :beer: It's a pretty good sized engine, Rob, bigger than it looks in the picture -- one of two that I bought about ten years ago at a model engineering show at the Precision Museum in Windsor, VT. Very similar engines are mentioned in an old Model Engineer, built by Arthur M. Balling of Balimore (issue 3308), and I'm certain this one was built by him. The seller did mention Baltimore, also. You can see the raw sand casting in some areas --n he built a big series of these as experiments to test out different valve gear.

Arrh , I do remember you mentioning the engine find now. Looks a well made engine  :thumbup:


Rob
Title: Re: Building a New Lathe
Post by: vtsteam on June 21, 2015, 03:50:38 PM
The headstock pattern has taken a lot more time than I thought to plan out and build -- it's a pretty simple shape, by the end, but getting there took it through all kinds of contortions! There a deceptive number of requirements since I'm working from an existing spindle and bearings, and bed, and I wanted to use a greensand core instead of making coreboxes. and placing cores. Plus I wanted to add a full length bearing cap, The headstock rides inside the ways, rather than outside. Then adding draft, machining allowance, etc. Yet keeping it within the melting capacity of my furnace. All kinds of things fighting each other....

Anyway, here is the headstock base pattern, with, I hope, everything I wanted together and sized right with allowances. It will need 3 new flasks, and I might have to make a bigger crucible. But those things are handy to have, so i don't mind.that part. The bearing cap pattern is started, but not done yet.

(http://vtsteam.com/Lathe/HeadstockBasePattern.jpg)
Title: Re: Building a New Lathe
Post by: mattinker on June 21, 2015, 06:12:31 PM
It's surprising how the apparently simple patterns can be very complicated!

Regards, Matthew
Title: Re: Building a New Lathe
Post by: RussellT on June 22, 2015, 04:03:04 AM
Hi Steve

That looks very solid.  :clap:

Where is the drive going to be?   :scratch:  I'd assumed that since you were using bearing caps to make the spindle removable there would be a belt between the bearings - and that making the spindle easy to remove would make belt changes simple.  It doesn't look like that's your plan - unless you're going for underdrive.

Russell



Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 07:38:10 AM
Very true, Matt!

Russell, drive is at the aft end -- variable speed DC motor. I split the bearing housing for reasons other than belt changes:

Quote
It  would be nice to be able to remove the spindle assembly without having to use a puller. It would also mean I could do the casting in two parts, and more easily fit a heavy casting pour in the crucible capacity I have.....

...Another helpful aspect if I can split it is that I can probably use the same boring bar and setting to bore both bearing recesses at front and back without changing anything. Each recess has an inside lip, and the boring bar can't make it through that, but if the cap was removed the tool bit could face up, slide through to the other side, and then replace the cap, and bore the other recess.

I would definitely prefer to do it that way than remove the boring bar from the boring jig setup, or move the tool bit in and out to cut both recesses.

I might also make up more than one spindle for this lathe down the road. I'm not too enthusiastic about the design of the  7x14 mini-lathe spindle. I made several swappable spindles for the Gingery lathe.
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 08:04:21 AM
This is the bottom view. That is going to be a difficult greensand core to preserve. I'm going to have to cope down for the 4 projections you see here. The flask has 3 parts -- the center part is exactly as tall as the pattern.

The bearing journal area will also be pretty interesting to try to mould with all the other stuff going on -- two part sprue, etc. and probably several rolls. Though i keep thinking it through, I haven't got it completely thought out yet. I expect the first time molding will just be a practice run to reveal what I should have done, and I'll have to start over. Lets hope it isn't more than three times! Working outside the sand dries out if you take too long to get something molded, and then you get drop outs and sand in the casting. This baby is going to be heavy to roll, and carry, too. Should be interesting!

(http://vtsteam.com/Lathe/HeadstockBasePattern2.jpg)
Title: Re: Building a New Lathe
Post by: mattinker on June 22, 2015, 08:24:13 AM
Why don't you want to make it with a core? Your pattern is almost a core-box in it's self. For difficult "green sand" cores (petrobond in my case!) I've found nails or short pieces of small section re-bar usefull.

The best of luck with it, regards, Matthew.
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 09:53:15 AM
Well Matt I don't particularly like making hard cores if i don't have to -- they are more additional work than making the pattern and part itself, and consume more materials. There are more things that can go wrong with the casting as a result. Off gassing, too hard a core, too soft, misplaced, softened in greensand by delay.

I don't mind cylindrical baked cores, since I can make and bake them easily in split pipe shells that I already have. But building complex highly finished core boxes (if they can be avoided by design) and baking cores feels to me like a delay. Production has different needs than I do, and hard cores can be made by the dozen (or hundred) to ease casting there. I'm impatient, and I cast practically everything one-off (unless I mess up!) so I design patterns for greensand cores where possible.

Besides I like a challenge in simplifying designs to use the minimum of materials and process complexity. This is a simple pattern, really. I may have a tricky time molding this piece because I don't do it every day, but I'm sure an old time sandcrab wouldn't think twice about assembling this mold. Who knows it may come out easier than I think -- will be casting today.....
Title: Re: Building a New Lathe
Post by: awemawson on June 22, 2015, 12:05:56 PM
... do it Steve - just need some chaplet pegs to support it :

http://www.gsfoundry.co.uk/chaplets.html


Incidentally, talking of loose bits in patterns, how do you like this Perkins 2 cylinder digger engine casting where they have obviously screwed a plate on the pattern for variable information, giving perfect impressions of the screw heads  :lol:
Title: Re: Building a New Lathe
Post by: NeoTech on June 22, 2015, 01:49:49 PM
This is a brilliant thread Steve.. just awesome. =)

 :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 02:48:19 PM
Well here we go, I'll give you a blow by blow photo shoot of today's attempt.

I taped closed the rough journal -- a little trick I've used once or twice. The journal is way undersized for machining allowance, so not critical. I've done this before on smaller castings and it has worked well. Tape has zero effective thickness, and you can sort of shape the sand with it by pressing while molding to yield draft.

Well, better for something this big would have been to make 2 loose pieces to fit the journal sections, and included draft for the ends. But hadn't thought of it ahead of time, and like I say, the journals are undersized so not a big deal if the ends aren't perfect -- they are just added so I don't have to bore off so much metal, and to reduce the size of the crucible needed to fill this mold:

(http://vtsteam.com/Lathe/HeadstockBasePattern3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 02:57:15 PM
Pattern in the middle one of the 3 flasks, a section of sprue -- flask and sprue are the same height as the pattern.

It was a beautiful day, but not for molding outdoors! Lots of sunshine and wind they dry out the sand fast and you have to work quickly, especially opening up 3 sections and with a hanging greensand core (the journals) and coping down. Not possible working fast and taking photos, but Madmodders deserve a looksee so we did the best we could under the circumstances!  :mmr:



(http://vtsteam.com/Lathe/HeadstockMolding1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:00:23 PM
Ramming up:

(http://vtsteam.com/Lathe/HeadstockMolding2.jpg)
Title: Re: Building a New Lathe
Post by: Eugene on June 22, 2015, 03:02:37 PM
Steve,

Just a plea ... if you do have to make a new crucible, could you give us a run down? I can see one on the horizon.

Eug
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:04:40 PM
Rammed up and molding board rubbed in:

(http://vtsteam.com/Lathe/HeadstockMolding3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:10:15 PM
Sure Eugene. Unfortunately, I didn't this pour...... more later....:beer:

Middle flask, first roll:

(http://vtsteam.com/Lathe/HeadstockMolding4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:13:51 PM
Coped down to pattern and cleaned up:

(http://vtsteam.com/Lathe/HeadstockMolding5.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:18:29 PM
Dusted with parting, drag set in place ready for filliing:

(http://vtsteam.com/Lathe/HeadstockMolding6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:23:45 PM
Drag rammed up, molding board rubbed in, second roll.

I had to cope down here a little, too and clean up:

(http://vtsteam.com/Lathe/HeadstockMolding7.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:29:36 PM
Cope flask in place, dusted, second sprue pin added, riser added, ready to ram up:

(http://vtsteam.com/Lathe/HeadstockMolding8.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:38:02 PM
Rammed up the cope, rapped the sprue pin and riser and pulled both, pulled the cope off. I had a little break out at the journals, but nothing to bother with -- sand is drying too quickly to try to repair -- just more to bore out when the time comes.

Next time I'll probably fill similar journals with two loose pieces with drafted ends.

(http://vtsteam.com/Lathe/HeadstockMolding9.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:44:26 PM
Carefully lifted the middle flask to reveal the pattern on the drag:

(http://vtsteam.com/Lathe/HeadstockMolding10.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:51:50 PM
Carefully removed the pattern to leave the greensand core. Top of core is a little ragged, but that will just be flash -- no casting there. Good corners, nice prints in the drag, and you can see where the pattern was coped down -- there's a raised sand base. Not bad for the first try!

(http://vtsteam.com/Lathe/HeadstockMolding11.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 03:58:30 PM
Gates cut,  beginning to reassemble:

(http://vtsteam.com/Lathe/HeadstockMolding12.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 04:02:12 PM
Riser gates cut, cope on, pouring basin smoothed, ready to pour:

(http://vtsteam.com/Lathe/HeadstockMolding13.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 06:04:22 PM
And after cooling, first view with the drag removed looks promising. I'm a bit worried because I had a short pour and didn't fill the riser, even though I melted 18 lbs and absolutely filled my largest crucible to the brim. Metal is home mixed ZA-12 using pure zinc ingot and 11% 6061 aluminum:

(http://vtsteam.com/Lathe/HeadstockCasting1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 06:08:42 PM
The bottom of the casting looks good, no problems evident and the core stayed together:

(http://vtsteam.com/Lathe/HeadstockCasting2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 06:17:55 PM
The top looks a little rough, but might be okay. There's a lot of flash because the sand dried out and i lost a bit of the edges and corners in re-assembling. And the half filled riser didn't prevent some shrink cavities, but they don't look too deep. It may be that i gave enough machining allowance to remove them, we'll have to see. And the journals filled with some material, but we knew that would be happening. This casting might work out. I'll have to rough mill the base to get a idea how far I can go to bring that top surface down....

(http://vtsteam.com/Lathe/HeadstockCasting3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 06:35:50 PM
After chipping out some of the journal and casting flash with a chisel and rough milling the bottom and top flat and parallel, there are only two shallow shrink cavities on the top surface. Setting the headstock on the lathe and checking centers with the tailstock it looks like I'm still .063" high, which will probably allow me to mill those cavities completely out. The journal will be bored quite a bit deeper and steps for the bearing added There's plenty of allowance to clean up the outside, too. So we'll pronounce this casting successful!  :med:

(http://vtsteam.com/Lathe/HeadstockCasting4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 06:43:57 PM
A look inside the bottom shows the greensand core worked very well -- a clean interior with sharp corners. I didn't use chaplets, but would have if I'd run into trouble removing the pattern:

(http://vtsteam.com/Lathe/HeadstockCasting6.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2015, 06:55:31 PM
And a belated thank you to Andrew and Neo!  :beer:
Title: Re: Building a New Lathe
Post by: mattinker on June 22, 2015, 06:56:53 PM
I think this looks like you deserve the special honorary old sand crab award for this casting!

I'm glad you got it first go, regards, Matthew.
Title: Re: Building a New Lathe
Post by: RobWilson on June 22, 2015, 07:03:19 PM
 :bow: :bow: :bow: :)  Belting series of photos Steve  :thumbup:

And glad to hear the casting is a keeper  ,  :ddb:  looking forward to seeing it machined up  :dremel:


Rob
Title: Re: Building a New Lathe
Post by: tom osselton on June 22, 2015, 07:25:16 PM
Well done! I haven't tryed that yet I'm still getting tools to make patterns with, almost there though just a good sander to go! I bought 130 lbs of aluminum scrap and about the same in brass from a buddy today so I'll be pouring ingots for a while!  :D
Title: Re: Building a New Lathe
Post by: awemawson on June 23, 2015, 03:06:26 AM
It came out nicely Steve

As the base isn't sliding, but just bolts down, it doesn't really matter if those cavities remain.
Title: Re: Building a New Lathe
Post by: vtsteam on June 23, 2015, 10:03:49 AM
Thanks, Matt! :beer:

Rob, thanks! The draft can be machined off of both ends. Walls are 7/8" thick. Thinking about how to make a boring bar for this -- not sure if this stuff will need carbide.  :scratch:  :beer:

Tom, thanks, you should be happy casting with all those materials!  :beer:

Andrew, actually, the headstock does slide -- driven along the ways while being bored, and will be fitted with slides and gib just like the tailstock. But the view shown with the small shrink cavities is the top of the base, where the bearing cap goes. The bottom has no casting defects. The top will probably be final machined off, eliminating the cavities altogether (I hope).  :beer:
Title: Re: Building a New Lathe
Post by: mattinker on June 23, 2015, 11:38:40 AM
Steve, you don't need carbide! ZA12 machines beautifully with high-speed steel, the sensation I have is sort of half way between mild steel and Al, Al with the crispness of steel, when I first read about ZA12, it was described as "machining like a dream" well honed sharp tools with what would be too fragile for steel points work well. It is softer than one would think from filing it. Sharp coarse files work better than fine ones, the coarse ones can get into the surface whereas the fine ones load up and skate. For machining, the same is true, you need them sharp and coarse, points that can get into the metal!

I think your going to enjoy the next phase, I'm looking forward to hearing about it!

Regards, Matthew
Title: Re: Building a New Lathe
Post by: vtsteam on June 23, 2015, 10:37:34 PM
Thanks Matt -- daughter birthday, relatives, 4th July, etc all requiring time out of shop, so haven't had time to test well yet. I did notice a lot less shrinkage on cooling than ZA-2, so maybe will have different qualities machining, too.
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2015, 06:10:45 PM
I managed an hour today and cleaned off the outside of the headstock. I need to mill the base so it will drop down between the ways next and make the slides and gib.

(http://vtsteam.com/Lathe/HeadstockCasting7.jpg)
Title: Re: Building a New Lathe
Post by: shipto on June 27, 2015, 05:43:01 PM
Cant believe I missed this thread for so long. Excellent job  :thumbup:
Title: Re: Building a New Lathe
Post by: krv3000 on June 27, 2015, 06:03:40 PM
brill you is making good progress  :clap: :clap: :clap: :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on June 28, 2015, 11:44:54 PM
Dwayne, Bob, thank you kindly!  :beer: :beer:


Title: Re: Building a New Lathe
Post by: NevadaBlue on July 13, 2015, 01:48:08 AM
Very impressive for sure! I jumped from page 5 to here... now to go and digest the rest.


Most fun to watch!  :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2015, 12:00:26 PM
Thanks Nevada -- sorry I didn't say so sooner -- been away from the project for a few weeks, with chores and a little wood dabbling. Will be back to this after the break from it gets old....
Title: Re: Building a New Lathe
Post by: trapper on July 29, 2015, 11:43:28 AM
Hi,if you lived in England l would offer you this machine its rated highly in America but ignored in this country,every bit as good as the Boxford but at Auction they make peanuts whilst the Boxfords make fortunes.I was told by my American friends that these are a joy to be worked on, and they are a very smooth cutting lathe highly underated but l think its simply lack of knowledge about this machine.Its a 10ins Leblond Regal aged 72yrs old gears are imaculate and out live any owner
Title: Re: Building a New Lathe
Post by: vtsteam on July 29, 2015, 03:22:23 PM
HI Trapper, thanks for the thought! Yes indeed LeBlond's are highly rated over here. I once secured a large newer LeBlondfor the firm I worked for and transported it in a big rental truck during a massive snowstorm from Rochester, NY to Vermont. Full day and evening there and back -- quite a ride!!

Of course I'm enjoying building my own lathe by now -- taking a break from it during the summer, but will pick it back up when the weather cools. Tons to do right now outdoors.

Thanks for the thought though, and it certainly would be a nice acquisition! :thumbup: :beer:
Title: Re: Building a New Lathe
Post by: trapper on July 30, 2015, 09:15:54 AM
l look forward to your progress and the finished results a nice and interesting project, could end up with a nice machine to suit your needs
Title: Re: Building a New Lathe
Post by: vtsteam on July 30, 2015, 09:06:09 PM
I'm really looking forward to it. And I have an interesting (I think) take on a milling attachment for this one, different than anything I've seen. The carriage has been laid out wth this in mind. Everything has been thought about with the idea of making my tiny nearby winter shop sufficient to do reasonable size engine work on a lathe/milling combo this small. Stiffness and rigidity in a small homemade lathe have been a priority.
Title: Re: Building a New Lathe
Post by: Manxmodder on July 31, 2015, 10:03:47 AM
agree with you,trapper,LeBlond lathes are very much worthy of consideration as a workshop lathe.

Steve,I am also looking forward to you picking up with the lathe build project,it's been a great thread to follow so far.....OZ.
Title: Re: Building a New Lathe
Post by: trapper on July 31, 2015, 02:30:35 PM
The way some people on here can improve/rebuild things a Leblonde could be turned into a rolls royce of a lathe,especially at the prices that they can be bought-there was one for sale last year and l felt really sorry for the guy selling it.It was in a family buisness and they had it for 50yrs(rarely used) it was the next size up from mine 14ins(7ins billet)He was buying a colchester to go in the space so he had it on at £350 plenty of assesories and it was in really nice looked after condition still had the original paint on and even that looked good,I t didnt sell,relisted didnt sell again,told me if it didnt sell second time he knew someone who wanted it for free,So one mans loss another mans gain,he got it for nothing-and l can tell you this he has got a lovely lathe,Mine cuts ally and stainless without effort and the excellent finish is automatic,at its best l had a coolant system on,an inverter,a dro,these are now on my other lathe and the Leblond has its original single phase motor back on.As everyone knows its much better 3phase.These machines become available now and then at give away prices and anyone looking for a well made lathe couldnt go wrong with one-ideal if you havnt got a fortune to spend
Title: Re: Building a New Lathe
Post by: Homebrewer on June 22, 2017, 01:32:30 PM
I'm new around here but last night I read every page of this build log.  I was curious if you were able to finish this lathe up?
Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2017, 07:49:47 PM
No, sorry, but maybe after I clear up some necessary projects around the house i can come back to it. The interest is definitely coming back for machine work. It had waned for awhile. Reading here is helping rekindle it. Thanks for asking! :beer:
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 26, 2017, 04:24:04 AM
2 time reading this build, and still being impressed at the work you do  :thumbup:
some years back i went down the diy route my self, building a milling machine, though in my search for a cross slide table, i found a cheap machine and purchased that, now where i am on number 2 machine, i still regred that i dident finished the diy version, since it actualy was better than what i have now (lux drimill ry20)
who know, maby some day i will build one again  :zap:
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2017, 07:48:08 AM
I hope you will Neubert, and show us pics, while you do!

I've had the same experience in the past of buying a machine and then realizing the disappointment of no longer needing to make one.

I know I will finish this lathe, when I can, and I originally intended to make it a halfway decent mill of it, too. I planned to sell some of those other machines when this one proved out.

There's a big difference for me in satisfaction in using a tool I built, and having it just what I need, the way I imagined it. The Gingery lathe and attachments were like that. This one was designed to be a much more rigid machine, but not much larger in footprint.

I do own a 12" x 36" Craftsman lathe, but I don't need the 36" length. This machine has the same ways dimensions and rigidity as that one, but will be sized closer to the Gingery in footprint. So I hope it will be capable of some reasonable milling, and solid turning without as much concern over chatter.
Title: Re: Building a New Lathe
Post by: vtsteam on June 27, 2017, 09:26:42 AM
Well, funny, it's been exactly 2 years to the day since I stopped working on the lathe. Re-reading this thread and you guys' comments (and a rainy day) have got me headed out to the tiny shop to clear off space around the old project. I'll take a look at what I've got, and think about the next step I need to take in finishing it.  If I devote a half hour or so out of the day or more when things are slow, maybe we can get this lathe up and cutting this summer.

Anyway, off to do shop cleanup......  :beer:
Title: Re: Building a New Lathe
Post by: NormanV on June 27, 2017, 10:24:54 AM
 :D
Waiting with anticipation!
Title: Re: Building a New Lathe
Post by: vtsteam on June 27, 2017, 06:55:54 PM
Thanks Norman! :beer:

I cleared off the lathe's bench in the tiny shop, but first had to work on the bench. Several drawers I needed to put away tools and other odds and ends in were sticking.

So I found my block plane, but found it was dull. So I went back to the house to get my Japanese waterstone, but found its surface clogged from too many kitchen knife sharpenings. So I went back to the shop for a piece of 80 grit wet or dry sandpaper, and cleared the grain and straightened the stone on a flat surface. Then I sharpened the plane. Then I went to work on the sticking drawers.

Once they slid okay, I decided to make drawer handles (long overdue), so I did that (pic in the Tiny Shop thread). And had a lot more joy putting things away.

I finally dusted off the bench under the lathe, and swept out the shop floor. All was in order, finally!

So, where was I last on the lathe? What was going to be my next step? Working without drawing plans has its disadvantages!

Looking at the headstock, my best guess was that I would have made a pattern and cast the headstock cap. But I'm not ready to resume casting yet -- sand is all dried out, and all the casting stuff needs to be organized.

So I think I will start with machining the headstock base, where it will slide on the ways. After machining I'll need to make a retaining plate, a gib, and drill and tap for gib screws. The headstock will slide on the ways just like the tailstock. This will facilitate boring it for the bearings. I'll need to make the headstock cap and fasten that to the base with a few shims in place for future adjustment before boring

After boring, it will be fixed in place permanently with clamps and through bolts at the end of the lathe.

Title: Re: Building a New Lathe
Post by: Homebrewer on June 27, 2017, 10:46:44 PM
Hey, you needed an excuse to go organize the shop, right?!

Sent from my SAMSUNG-SM-G900A using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on June 28, 2017, 07:07:31 PM
Homebrewer, this is true! :dremel:

Today we finally cut metal. I milled the bottom of the headstock where it slides and the rectangular bosses that will bear against the inside of the ways while boring for the spindle bearings. There were a lot of things to think about -- how much space needed for a gib, whether the headstock was centered and at the right height relative to the tailstock and ways, whether there was clearance for the cross slide shears, whether the bosses had enough depth, etc.

But we managed to get through it all. One help was sighting through the tailstock bore at the far end. The reduced size hole at the hand wheel end acted like a scope, and helped me check centering. All in all a satisfying hour of messing about with metal, between mowing sessions with the tractor. Rain predicted for the next few days, so maybe more time for the lathe.

(http://vtsteam.com/Lathe/HeadstockSlide1.jpg)

Trial fit in place:

(http://vtsteam.com/Lathe/HeadstockSlide2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 29, 2017, 09:13:44 PM
Today I milled to finished depth the headstock slide bosses, and marked them out for the gib screws. I drilled to suit a 10-24 tap.

The holes were a little tricky to drill because the headstock is tapered towards the top, so I had to block it square. My drill table in the tiny shop is very small, so no way to clamp the headstock down. I just had to hold it in position and hope for the best. Worked out well, though.

Zinc alloys tap very nicely. I used a little kerosene as a tapping fluid, and the holes were finished in short order. I had to shorten some stainless socket head cap screws so they would fit between the slide bosses. And I had to relieve the casting a tiny amount to clear the screw heads, using my electric die grinder. But it all worked out.

(http://vtsteam.com/Lathe/HeadstockSlide5.jpg)

Next I looked for some steel to make the bottom slide retainer plate. An old rusty piece of flame cut metal was all I had of large enough size and appropriate thickness so I had to grind off the dirt and rust, band saw it to rough size and mill it all over. After filing It will be drilled and screwed to the 4 headstock slide bosses. The screws will just clear the gib screw holes -- the latter were offset to the outside of the bosses for that reason. You can see the offset in the photo, above.

Below is a photo showing a scrap section of the 3/8" way material sandwiched in position between the headstock and the new slide retainer plate. The bosses were milled 3 thousandths lower than the way thickness, so that some 1 thou brass shims can be inserted to adjust for a close sliding fit.

I'm undecided on whether to actually make gibs. Since the headstock will only be sliding temporarily for the spindle boring operation, I'm thinking that the gib screws may be all that's needed. The headstock can be adjusted now to slide on the ways without play, and quite freely, with just the gib screws. I'll think about it.

Anyway here's a pic of the assembly as it stands now:

(http://vtsteam.com/Lathe/HeadstockSlide4.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on July 01, 2017, 11:00:33 PM
Drilled and tapped for the plate, made up the shims and mounted the headstock on the ways. It fits without play, yet slides nicely along the full length.

(http://vtsteam.com/Lathe/HeadstockSlide6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 01, 2017, 11:29:51 PM
This afternoon I had some time to work on the lathe during a thunderstorm. I decided it was time to mount the leadscrew bearings. This meant drilling and tapping the lathe bed, which is 3/4" thick hot rolled steel.

Tapping the first hole:

(http://vtsteam.com/Lathe/LeadscrewBearing1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 01, 2017, 11:35:11 PM
After tapping all the way through -- very slow going with this tough steel and working horizontally -- I mounted the cast bearing, which I'd drilled earlier for mounting holes and an oil hole. I locked the carriage to the leadscrew, as I had earlier when marking the first hole position. I used a transfer punch to mark the second hole;

(http://vtsteam.com/Lathe/LeadscrewBearing2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 01, 2017, 11:41:49 PM
Tjen it was a matter of step drilling for the other hole first with a 1/8" spotting drill, and later with the tapping drill, and then tapping again. I took it all slowly, no rush, to make sure all was in alignment, and especially avoiding breaking the tap. Sometimes it took only an eighth of a turn before I felt it was too tight and had to back out and clear it.

Spot drilling:

(http://vtsteam.com/Lathe/LeadscrewBearing3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 01, 2017, 11:44:56 PM
Finally the bearing could be mounted.

(http://vtsteam.com/Lathe/LeadscrewBearing4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 01, 2017, 11:51:08 PM
The front bearing mount was much easier, as it goes into an aluminum extension that serves as a cover and heatsink for the internally mounted stepper motor, which will drive the leadscrew.

Finally the leadscrew was fully mounted in the bearings.

As a check, the carriage slid along the ways without contacting the half nut, while it was open. And closing it locked it in good alignment with the leadscrew. There was no need to slot the bearing screw holes for adjustment. I'd measured carefully with everything clamped in place before starting to drill the mounts. I'd hoped that's how it would work out, and it did.

Both bearings mounted:

(http://vtsteam.com/Lathe/LeadscrewBearing5.jpg)
Title: Re: Building a New Lathe
Post by: tom osselton on July 02, 2017, 12:06:40 AM
Looking good! :thumbup:
Title: Re: Building a New Lathe
Post by: PekkaNF on July 02, 2017, 04:19:38 AM
I must say that I enjoy watching this. Like the work and rationale. many just show what is done, without telling the reason or thought process.

The head stock adjustment provision. Not sure if I got it right. Are you boring it in situ or planning to mount it somewhere middle for boring through? Planning to use same size shimms all over, during boring?

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on July 02, 2017, 09:22:29 AM
Thanks Tom, Pekka!

Pekka the headstock will only move for a short time while being bored, after that it will be slid to its final position and bolted in place.

The shims only adjust the tightness on the ways while sliding. Not the headstock height. They are located under the slide retaining plate where it is screwed on.

The shims in the headstock are probably unnecessary, assuming you are exact in getting a perfect sliding fit when surfacing the "legs" (bosses?) at the bottom of the headstock. Not too sticky a sliding fit, and not too loose. But I'm used to doing it this way, and it is a simpler matter to make the legs a few thou short, and then pad back to a perfect fit on the ways thickness with shims. (remember also that the ways thickness was actually determined by scraping -- not a generic .375" any more)

For regularly sliding lathe parts (like the carriage)  the shims also serve the purpose of allowing you to adjust for wear over the lifetime of the lathe. With one thousandth of an inch brass shims, you can remove one at a time to adjust out wear the same amount. With four separate shims at corners, like I have on this lathe, you can also adjust one corner at a time to remove a small amount of rocking if you have any..

But again, this is all unnecessary for the headstock, as it won't wear over time. Just my habit, and very simple to cut the legs a little short, and pad back to a good fit with shims.

Just a word on why the headstock is made to slide. When boring, I will use the tailstock as a boring bar holder. It will be fixed in place. I will temporarily mount a pulley back there and use the tailstock as a headstock.

The real headstock will be attached with a nut to the leadscrew and move while boring.

By doing it this way, the tailstock and headstock will end up with concentric bores. And also the bore will be exactly parallel with the ways, since the direction of movement is constrained by sliding along those ways. Since I started out with a pre-existing finished tailstock casting, I am operating in the reverse of the normal procedure. Which would be boring a tailstock using a headstock to hold the boring bar.

When boring the spindle location by sliding the headstock over the ways, even if the boring bar is slightly canted, the bore will be parallel to the ways. Canting would just introduce a very slight elliptical shaped hole, but still exactly parallel to the ways. Since I will be very careful to align the boring bar first, any elliptical error will be negligible. It would take a fairly big and obvious angle to make a problematic degree of ellipse. If you do the math for a couple degrees off, it still produces a very small circular error.
Title: Re: Building a New Lathe
Post by: vintageandclassicrepairs on July 02, 2017, 05:03:57 PM
Hi Steve,
I glad to see you are back at the lathe build  :clap:
You could have made the excuse that the castings were "curing"  LOL
Honestly, I missed your contributions to the forum

Keep up the good work
John
Title: Re: Building a New Lathe
Post by: vtsteam on July 03, 2017, 08:23:20 AM
Thank you, John.  :beer: I've slowed a little -- yesterday's project time allotment was spent thinking about the headstock cap -- which I'm going to have to make a pattern for and cast. Fitting it to the bearings, and also bolting it down is a little tight for clearances due the lower casting dimensions --- already fixed. This will be the first thing I've ever made with tapered roller bearings. They take up a lot of room.

I'm hoping I can squeeze in 5/16" cap bolts instead of 1/4"..... they both seem a little small, by eye.
Title: Re: Building a New Lathe
Post by: vtsteam on July 03, 2017, 08:39:01 AM
I know to set the axial pre-load when installing the spindle, but I'm wondering how much installed radial load, (if any) is usual for tapered roller bearings?

The question comes about because I am going to have a split housing. I don't want to compress the bearing more than necessary with the cap. The bearing space will be bored with the cap in place, and a few shims between, for adjustment, although hopefully unnecessary..

Is a slightly tight fit all that is necessary, or is there usually a required minimum interference fit spec for pressing them into a normal (un-split) bearing housing?

I know from replacing bearings in existing equipment (and replacing wheel bearings), you need a puller, but re-installing there seems to be just a light interference fit. If it isn't critical, that should be pretty straightforward to achieve.
Title: Re: Building a New Lathe
Post by: krv3000 on July 03, 2017, 01:59:46 PM
in a word brill
Title: Re: Building a New Lathe
Post by: PekkaNF on July 03, 2017, 04:15:31 PM
You want rings fixed on seat and on shaft. If the outer ring moves, it will rotate slowly and soon it will be loose. Therefore sometimes the ring is glued if it can't be pressed. There are some variations, but this is the main rule.

Still wondering this headstock booring. I have a Gingery's book and I am familiar with the principle. Was wondering if you considered using the tailstock to bore bearing for fixed steady, that could be put permanently behind of the head stock for support when ou are boring the head stock?

This is most interesting project in long time.

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on July 03, 2017, 05:02:54 PM
Thanks Bob!
I miss seeing you restore an indicator every once in awhile! I have one that I am working up the courage to work on a .0001" version with a very yellowed lens and zero off to one side. Cheers!  :beer:

Pekka, that makes sense, and since I have a cap with shims, adjusting a for little pressure on the outer bearing ring to keep i from spinning will be easy.

I see, re the boring bar -- make a boring bar with the cutter in the center instead of a cantilevered bar and support the far end in a temporary steady behind the headstock. Good idea -- I like it! The boring will go faster because chatter will be reduced to allow a deeper cut.  :thumbup:

 :mmr:

Title: Re: Building a New Lathe
Post by: vtsteam on July 03, 2017, 06:54:41 PM
No work on the lathe today, I'm building my daughter a playhouse for her birthday. Dropped a hemlock tree, and hauled a section to the sawmill, then cut siding for the structure, and nailed it up by dinner time. Too tired to go out to the workshop.
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 04, 2017, 03:52:00 AM
I hope you will Neubert, and show us pics, while you do!

I've had the same experience in the past of buying a machine and then realizing the disappointment of no longer needing to make one.

I know I will finish this lathe, when I can, and I originally intended to make it a halfway decent mill of it, too. I planned to sell some of those other machines when this one proved out.

There's a big difference for me in satisfaction in using a tool I built, and having it just what I need, the way I imagined it. The Gingery lathe and attachments were like that. This one was designed to be a much more rigid machine, but not much larger in footprint.

I do own a 12" x 36" Craftsman lathe, but I don't need the 36" length. This machine has the same ways dimensions and rigidity as that one, but will be sized closer to the Gingery in footprint. So I hope it will be capable of some reasonable milling, and solid turning without as much concern over chatter.

If i build one i promice to take lots of pictures, but time will tell if i build one.
I do have one picture of the mill i build, only with a tiny proxxon cross slide table on it, and a 24 volt motor for testing purpose.
at the moment i am talking with a guy on a danish machinist forum, that when he is done using it, has offered mea scaltools bk45 mill drill at a verry fair price.
its a gearhead, barley used mine for 6000Dkr, cost from new in Denmark 30.000Dkr

But for sure it is a big satisfaction to use a tool that one has made by him self  :thumbup:

My lathe is okay, but far from a good one, its a weiss wm250v
Title: Re: Building a New Lathe
Post by: RussellT on July 04, 2017, 07:16:54 AM
Hi Steve

It's good to see you back on this project and forum.

I would have thought the main consideration with your proposed bearing design was that the outer race shouldn't be squashed out of round - which it might be if you removed shims from a round bore.  I think Pekka's suggestion of taking up clearance with some glue might be better than shims.

Russell
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2017, 09:39:05 AM
Neubert, great to see your homemade mill! I do love that kind of thing. It's the true MadModder style! How about a thread about it, if you have construction photos (or is there one already that I missed?)

Thanks Russell, good to be doing something here again!

I'm not worried about squashing bearings for several reasons. First is that I hope to bore to a good interference fit in the first place! Second is that, I would never compress a cap to the point of "squashing" a bearing. It's fairly easy to tell if it's deforming if you feel for any resistance as you twist the spindle back and forth while tightening the cap bolts.

All split bearings ever built, including very thin automotive plain bearing shells, have the same potential theoretical problem, but work in practice, IF the fit is reasonably close to start with. The bearing housing limits side expansion of the shell, which would create ovaling.

In the present case, besides a good fit, the adjustment range is .0005" per shim, since you can remove a .001 shim per side. Anyway let's not buy trouble, and hope for the best. Absolute worst case scenario of a terrible bore pass, I'll cast new parts, and learn a lesson!   :lol:
Title: Re: Building a New Lathe
Post by: awemawson on July 04, 2017, 10:15:07 AM
Steve,

You look to have ample meat around the spindle, that if things went pear shaped you could bore out over  size and fit a bush

Looking excellent so far  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2017, 10:28:53 AM
Maybe, Andrew. I suppose you could shim the circumference too, if oversized. Many possibilities. We'll see how ham-handed I am with the boring..... :wack:

Pekka, I'm still thinking about the steady rest behind the headstock idea .....I just realized something. I think I already have one to fit this lathe, since I made the ways the same dimensions as my Craftsman lathe! How simple!   :ddb:

I have to go check.........
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2017, 12:24:00 PM
Well, no, after measuring it was originally for an 11" lathe, I had made a riser block to suit it to the 12" Craftsman, but removing the block didn't bring it down to suit the 9" new lathe. I could mill the base down, but don't want to.

However, I also had once made a steady rest for the Gingery lathe, mine is a 7-1/2" dia. So bolting a 3/4" riser block to that steady is just a matter of casting one, and I can suit it to the new ways width. Easy mod. And I actually like the Gingery steady better than the bigger cast iron version. So, yesss!  :ddb:

The Gingery steady sitting on the new lathe:

(http://vtsteam.com/Lathe/SteadyRestonNewLathe.jpg)
Title: Re: Building a New Lathe
Post by: PekkaNF on July 04, 2017, 03:38:28 PM
That looks like a plan!

Pekka
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 04, 2017, 06:19:23 PM
Neubert, great to see your homemade mill! I do love that kind of thing. It's the true MadModder style! How about a thread about it, if you have construction photos (or is there one already that I missed?)

I would love to make a thread about it, but i do only have that one picture, and the mill is long gone, in exchange for first an x2 mill and since the lux drimill ry-20 that i have now. :Doh:
Title: Re: Building a New Lathe
Post by: vtsteam on April 29, 2018, 05:56:41 PM
This winter and spring really took a toll on the little shop -- lots of rain alternating with deep cold froze ice onto the floor. It's all now just thawed, but still very damp in there. Lots of surface tool rust to deal with, and my furnace lining got wet and crumbly and will need to be renewed. BUT, I'm going to work on the lathe again -- just read through this whole thread to get my bearings again, so to speak. I think the next step I had planned was casting the headstock cap. I'll need to repair the furnace for that.....
Title: Re: Building a New Lathe
Post by: Neubert1975 on April 30, 2018, 10:09:03 AM
Good to see you back on the lathe build  :D

In December the guy who had offered me the scantool mill drill contacted me to let me no that i could now get it, and even at a lower price than first (now around 800 usd)
it is now sitting in my workshop and waiting for me to get ready to make some metal chips again  :med:

Hopefully it will happen soon, though helf is setting the pace for me unfortunately.
Title: Re: Building a New Lathe
Post by: vtsteam on May 05, 2018, 09:47:29 PM
Finally something new accomplished. After rehabilitating my Tiny Furnace, I had time today to make a pattern for the headstock cap.

(http://www.vtsteam.com/Lathe/HeadstockCapPattern.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2018, 06:46:14 PM
Not a promising day or time to begin casting -- it's rained all day, and I finally cleared a little space under the open shed roof and located most of my stuff, weighed out some zinc and some 6061 aluminum to alloy with it (Zamak-12 -- 11% 6061). I had to run out and get propane as I was out of charcoal. No bench to work on, just the concrete floor. But cast I must! It was 4:30.

Stooped over flippin flasks isn't ideal. But anyway...... Also I realized I hadn't put core prints on the pattern, and I didn't want to machine away the lathe spindle passage. So I thought I'd be clever and try a simple half core, baked and laid on the drag. I decided to experiment and just ram and bake some greensand as the core, rather than the old tried and Gingery molasses and walpaper paste mix. Lots of new variables!

Anyway, here's the start:

(http://www.vtsteam.com/Lathe/CapPatternOnDrag.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2018, 06:48:09 PM
Here's the baked greensand half core on the drag. Actually I was quite pleased with the way that baked out. Decent amount of strength and easy to place. BUT, it was a little too long, as you can see here and I had to cut out the cope a little to accommodate. Unfortunately by doing without core prints, I couldn't invert the flask and make this the cope, because the piece is loose. That reduced the head pressure I could achieve above the casting.

(http://www.vtsteam.com/Lathe/CapBakedGreensandCore.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2018, 06:55:40 PM
Here is the cope ready to replace. A little ragged around the sprue, because I'm working stooped over, and my back is under the shed roof dripline...but, hey I'm casting! You can see where I've relieved the end of the pattern hollow to accept the slightly too long core.  :wack:

(http://www.vtsteam.com/Lathe/CapCopeReady.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2018, 06:58:58 PM
And the pour. I had forgotten how extreme shrinkage is with Zamak. The sprue and riser were both topped up completely before it began to cool.

(http://www.vtsteam.com/Lathe/CapPour.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2018, 07:00:15 PM
Now that's shrinkage!

(http://www.vtsteam.com/Lathe/CapSprueShrinkage.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2018, 07:01:37 PM
Always hopeful at this point -- first sight of metal in the sand:

(http://www.vtsteam.com/Lathe/CapCastinginCope.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 06, 2018, 07:08:36 PM
But no cigar. Nice casting otherwise, but a giant shrink cavity in the center!  :wack:  I should have added core prints and done a proper baked core. Then the flask could have been flipped again putting the casting in the drag instead of the cope, and plenty of head pressure and molten metal to feed it.

Oh well, first time back casting after a couple year lapse, and my planned molding bench would have eased the back ache. But hey I POURED METAL today, and better things to come... :ddb:

(http://www.vtsteam.com/Lathe/CapShakeOut.jpg)
Title: Re: Building a New Lathe
Post by: Homebrewer on May 06, 2018, 11:37:53 PM
Glad to see you pouring metal again.  Can't wait to see this one running!

Sent from my SM-G950U using Tapatalk

Title: Re: Building a New Lathe
Post by: awemawson on May 07, 2018, 01:40:37 AM
A bit of 'bondo' and it'll be fine  :clap:

Seriously though I know the frustration of working without the right facilities. I remember when we moved here and all my tools were stored elsewhere the issues it raised
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2018, 04:47:39 PM
Thanks Homebrewer.  :beer: Don't give me any obviously workable heinous ideas Andrew! There's a can of Bondo in the shop.  :drool:.

No, no, get thee hence..! :whip:

Title: Re: Building a New Lathe
Post by: awemawson on May 07, 2018, 05:00:10 PM
All right use Devcon aluminium putty and you don't even need to paint it, it'll polish up nicely.

Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2018, 07:59:03 PM
I've decided to fill the entire casting with Zinc alloy. By re-casting!

So, second try, more comical than the first...... uh, well it started out good. I clamped a board to the pattern and drilled in from both ends to create a half hollow when taken apart. Then, you'll like this Andrew, Bondoed the rough wood finish that my paddle type bit left.

Fired up the furnace and placed the last casting back in the crucible, conditioned the greensand and laid the pattern into the drag, rammed, and rolled it:

(http://www.vtsteam.com/Lathe/CapSecondTry1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2018, 08:07:57 PM
A bit tight in there as you'll notice, above. But blithely continued on, rammed up the cope, pulled the sprue and riser bits, waited  for a melt, and poured. The sprue stayed nicely choked until the riser filled, and then suddenly they both plummeted back down while zinc poured out the parting line!  :bang:

Classic mistakes: too small a flask for the job, not weighting the cope down.  :wack:

I had forgotten that zinc weighs a heck of a lot more than aluminum, and will definitely float a small cope. Well, I suppose it's possible I got away with it because I saw a small amount of the pour  left in both cavities. But not very likely. Anyway, waiting for it to cool, so I'm posting this.  :beer:

(http://www.vtsteam.com/Lathe/CapSecondTry2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2018, 08:50:23 PM
Looked pretty good when I first broke some sand away:

(http://www.vtsteam.com/Lathe/CapSecondTry3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 07, 2018, 08:53:13 PM
But no such luck. That's a pretty short sprue!

I also noticed the surface finish wasn't much to write home about -- my sand was a little dry. I've re-hydrated for tomorrows attempt. I've only been able to cast after work at 5:00 PM, so once a day is about the limit.

(http://www.vtsteam.com/Lathe/CapSecondTry4.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on May 09, 2018, 08:49:21 PM
Third try this evening after work. I plopped sprue and riser right on top of the pattern. That put the two channels in from the flask edge, and put the hottest metal at the base of each for feeding the casting as it cooled.
Also weighted the cope down.

Much better looking pour....

(http://www.vtsteam.com/Lathe/CapThirdPour.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 09, 2018, 08:50:54 PM
Better looking shake out, too.

(http://www.vtsteam.com/Lathe/CapThirdPour3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 09, 2018, 08:53:45 PM
Top looks good. I hope tghere won't be any surprises when I cut the sprue off -- deep hole in the sprue -- I watched it sink down over several minutes. It was overflowing at the start. Zamak shrinkage is amazing compared to aluminum and cast iron.
Anyway, fingers crossed....  :med:

(http://www.vtsteam.com/Lathe/CapThirdPour2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 10, 2018, 09:32:15 PM
No such luck. A fairly deep hole directly under the sprue.

(http://www.vtsteam.com/Lathe/CapHole.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 10, 2018, 09:38:46 PM
This time however, I decided to try to repair it. The hole is nowhere near the bearings or cap bolts, and I could see the bottom. So I thought I'd just try melting a small amount of the same material, and pouring it into the hole. This is a lot easier with a low temperature melting alloy like Zinc. I figured there was nothing to lose, and the hole wasn't in a structural area anyway.

When I poured it full, I noticed immediate shrinkage beginning, so I topped up the hollow. That shrunk, too, so I dripped a little more on just to make sure!, Didn't want a repair with a hollow!

Here's the result:

(http://www.vtsteam.com/Lathe/CapHoleRepair.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 10, 2018, 09:42:21 PM
Machining it all back down the repair was all but invisible. I'm shining a light on it at the right angle to make it visible in the photo here -- the color is slightly different, and machine marks are different, but there is no visible seam. It looks like the metal actually fused.

So we'll call this experiment a success.  :ddb:

(http://www.vtsteam.com/Lathe/CapHoleRepair2.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on May 11, 2018, 02:26:55 AM
Excellent Steve :thumbup:

Good isn't it that with castings, however bad they are they can contribute to the next melt !
Title: Re: Building a New Lathe
Post by: vtsteam on May 11, 2018, 10:50:47 PM
Thanks Andrew! Yes and this poor 5lb lot of metal was poured three times  :zap:.

BTW, here's a photo of the same repair in daylight -- it's nearly invisible.

(http://www.vtsteam.com/Lathe/CapHoleRepair3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on May 11, 2018, 11:18:43 PM
So I dug out the spindle -- since I'm getting close to boring the headstock. I had sent for this one, standard Mini-lathe replacement, on sale from Little Machine Shop, and I must say I'm not enamored of it. Originally the idea was to save some time and machining by using a ready made, ground spindle, with morse taper , etc. But I really don't like that big hub on the end, behind the flange. It's not a bearing land, the bearing sits behind it. Therefore it adds 7/8" of overhang past the bearing.

(http://www.vtsteam.com/Lathe/Spindle.jpg)

If you add in the flange and an adapter plate to fit my chuck, we're talking 1-1/2" of overhang, not including the chuck thickness, which I think is about 4". My whole aim with this lathe was to increase stiffness wherever possible, and reduce chatter.

Another disadvantage is the loss of turning length that nearly 6" of overhanging components yields on this relatively small lathe.

So I've been thinking of cutting part way into that hub and moving the bearing closer to the flange. The only fly in that ointment is the spindle wall thickness getting too thin around the mouth of the morse taper (about 23mm ID) -- which is why I think the step is there.

So I've been thinking about increasing the journal land and bearing ID there. The original bearings for the nose of the spindle are spec'ed as 30206 rollers of 30mm ID. That gives roughly 4mm wall thickness at the bearing where it is located further back.

If I go to 35 mm journal, step up to a 30207, roller and move it forward I'll have 6mm wall thickness at the bearing, and lose 17mm of overhang. So I think that's going to be the plan.

Also, thinking about the whole flange, plus adapter plate, plus chuck thickness overhang, I'm considering eliminating the adapter plate and building the existing flange out to match the chuck's needs for register and attachment. That would probably mean brazing a ring onto the existing flange, and then turning it to suit.

In fact I've even considered extending that idea of flange improvement into a 9" faceplate, and just making a means to attach the chuck to the faceplate. I like faceplate turning -- most of my career on the Gingery lathe was faceplate turning, and I have a myriad of simple chucks and attachments for doing all kinds of work on that. I've seen people grip one chuck with another -- why not similarly grip a chuck on a faceplate?

Faceplates give the shortest overhang possible for gripping large work.

Maybe an ideal for me would be a faceplate and ER collet system, and dispense with the 3 jaw altogether. Anyway, things to think about.........
Title: Re: Building a New Lathe
Post by: Pete. on May 12, 2018, 01:35:34 AM
That wide land is there to allow space to fit the nuts on the chuck mounting bolts.
Title: Re: Building a New Lathe
Post by: mattinker on May 12, 2018, 02:53:38 AM
Excellent Steve :thumbup:

Good isn't it that with castings, however bad they are they can contribute to the next melt !
Steve,

The only draw back when re-casting the zinc alloys is zinc evaporation!

I have an Emco lathe that uses the same flange as the spindle you have. Instead of using a back plate to mount my four jaw, (a myford 7 one) I made the mounting recess directly into the chuck making things both shorter and lighter!

Regards, Matthew
Title: Re: Building a New Lathe
Post by: vtsteam on May 12, 2018, 08:30:49 AM
That makes sense Pete. They also use a 9mm thick plastic ring/bearing cover, inset into the headstock on the Mini lathes, and part of the spindle shoulder fits into that, so the overhang isn't so apparent. But it's still there.

Since I'm building a new headstock, quite different than the Mini-lathes, bolting the chuck or other accessories won't be a clearance problem. For one thing, the bearings and spindle can be easily removed because the headstock is split, with a cap. In fact I could swap spindles, w/bearings that way for some kind of specialty situation.

But also, my headstock cap is circular in section, and my 5" chuck mounts with a much wider bolt circle, that clears the headstock cap. So I don't need to fit an allen wrench between the headstock and back of the chuck.

I've though quite a bit about the spindle this morning, and I think I'm finally going to stay with the designed bearings, and instead of reducing the shoulder, I will turn off the present chuck mounting flange and register, and continue the shoulder diameter all the way out to the face of the spindle.

Then I'll make a faceplate to fit that journal diameter. The 5" three-jaw chuck will simply bolt flat to that faceplate with three bolts. These can be easily reached outside of the headstock cap.

I'll just start the bolts, indicate the chuck true by turning and taping it into position with a wooden mallet, and then tighten. Very quick to do, in my experience with my Gingery two jaw chuck.

By turning off the spindle flange and register, and mounting the faceplate flush with the spindle end, I will have eliminated the thickness of an adapter/backing plate.

Also, when I went to measure my chuck, turns out it is only 2-1/4" thick, not 4", a pleasant surprise. So I think I've got a plan to give the shortest overhang with what I have to work with, along with a fair amount of chuck and faceplate convenience for the way I work, and I will still be using the stock bearings I have on hand. The only operation to the spindle will be turning down the mounting flange to equal the shoulder diameter.
Title: Re: Building a New Lathe
Post by: vtsteam on May 12, 2018, 08:51:35 AM
Excellent Steve :thumbup:

Good isn't it that with castings, however bad they are they can contribute to the next melt !
Steve,

The only draw back when re-casting the zinc alloys is zinc evaporation!

I have an Emco lathe that uses the same flange as the spindle you have. Instead of using a back plate to mount my four jaw, (a myford 7 one) I made the mounting recess directly into the chuck making things both shorter and lighter!

Regards, Matthew

That sounds good about the chuck, Matt!

I don't think I lost any zinc by evaporation (except the figurative "evaporation": spills and such  :wack: ). It wasn't liquid for more than a minute, and I never heat zinc to fuming. (Brass is another matter - hard to avoid sometimes)

In almost all casting, I pour as soon as the last solid chunk disappears in the melt as judged by a stirring rod -- I'm not a great believer in super-heating unless occasionally trying lost foam casting. Excess heat or too long in  the furnace just makes for more shrinkage, and a worse surface finish.
Title: Re: Building a New Lathe
Post by: awemawson on May 12, 2018, 08:53:55 AM
Certainly stewing aluminium longer than strictly necessary is a recipe for absorbing hydrogen and getting aero chocolate like castings.
Title: Re: Building a New Lathe
Post by: vtsteam on May 12, 2018, 09:00:58 AM
We won't be doing that.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on May 13, 2018, 08:34:50 PM
I used a die grinder and files on the new headstock cap. Took awhile, zinc is very tough stuff.

Most of this weekend however was spent on setting up a casting bench and organizing things under the tiny shop's attached lean-to roof. Casting will definitely be easier soon.

The shop is no longer damp after a winter with ice on the floor. The new lathe has a few spots of surface rust, though happily, not on the ways. But I decided to start painting things, maybe a few pieces of the lathe a day. So I started with the headstock and tailstock. I still need to attach the lathe's feet, so the bed painting will have to wait for that.

(http://www.vtsteam.com/Lathe/FirstPaint2.jpg)

I'm thinking about making a boring bar and fixture for machining the headstock. I have a piece of 3/4" hot rolled steel, and a 3/4" bore cone pulley, so I think I'll use those.
Title: Re: Building a New Lathe
Post by: vtsteam on May 14, 2018, 09:29:47 PM
Spent this evening trying to make a Ironman style oil burner for the Tiny Furnace. I have a lot of used cooking oil I'd like to burn instead of buying propane. I also want to melt brass (quite a bit higher temps than Zamak or aluminum for that matter) for the next few melts of handles and such for the lathe, so I thought I'd take the time to work up a new burner. Not much success using a makeshift version I came up with after work in the few minutes I had before dark to try it out, but I think I can make improvements to get it going properly......we'll see tomorrow.

While I have a very successful Kwiky style atomizing burner on my larger oil burning iron furnace, I'd like to do away with the compressor, as that one needs, and use a blower-only as Ironman does. But I do need to scale his down for the tiny furnace and brass, both in heat output and size.

Also today, stopped down at Lester's old time machine shop and bought some 1-1/4" hot rolled, and 1-1/8" cold rolled -- the latter for the tailstock ram.
Title: Re: Building a New Lathe
Post by: vtsteam on May 21, 2018, 08:02:38 PM
I stopped down at Lester's old time machine shop. Found Lester in the back and we jawed for a half hour or so. Eventually I mentioned I wanted some hot rolled 1-1/4" round stock to make a boring bar, and my tailstock ram with. I'm using a tailstock casting that I bought from Ebay for a Craftsman lathe. Lester said why didn't I want cold rolled? I said well the bore is actually 1-1/8" and I'm not sure how worn it is, might need to turn it to an odd dimension, etc.

He said, well, I have some 1-1/8 cold rolled. Had it for a long while. I don't use it much. Okay I said, I'll take about three feet of both, then, just in case. So he cut me the hot rolled bar, and hunted up the cold rolled, which was on a shelf in an ancient cardboard tube, that just fit it. When he pulled the bar out, it was just under 3 feet, so I said that was fine. He charged me $22, and I could probably make six tailstock rams with that if I wanted to. He gave me the cardboard tube, too.

Well when I got it home, it was all coated up with sticky preservative stuff. I cut off 7" of it and cleaned it up with kerosene. Imagine my surprise when I saw it was ground polished stock! And the fit in the tailstock was absolutely perfect. perfect sliding fit. Like they were ground for each other.

So I guess I lucked out on that one. Maybe that's why it was in that protective cardboard tube. Thank you Lester!

The ram blank in the tailstock:

(http://www.vtsteam.com/Lathe/TailstockRam.jpg)

Title: Re: Building a New Lathe
Post by: awemawson on May 22, 2018, 03:59:32 AM
. . . just sometimes all the stars line up, and things work out well  :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on May 23, 2018, 11:35:20 PM
Thanks Andrew.  :beer:

I haven't been able to work in the shop the last few days as I'm also working at a job full time (temporarily only -- back to retirement June 1).  But evenings I've been working an hour or so at the kitchen table making up a bluetooth DRO for my mill using a Texas Instruments MSP430 Launchpad evaluation board, one Igaging style scale, and two digital calipers (I hope).

I've also thought of a new scheme for cutting threads simply (and mechanically) on this lathe, without the Arduino electronic leadscrew I had worked up earlier. I'm kinda excited to try it out.  :smart:  :zap:
Title: Re: Building a New Lathe
Post by: vtsteam on May 29, 2018, 10:40:37 PM
Got a minor bit done tonight -- bored the tailstock spindle  5/8" dia., 2" deep to accept a boring bar I'll have to make up.

You may have noticed I've removed the carriage -- I'm not going to use it to drive the headstock. Instead I'll temporarily connect the headstock to the leadscrew with a bracket. This shortens the length of boring bar I will need, which is all around better for this job. The tailstock ram, temporarily over-long, will be driven round -- acting as part of the rotating boring bar, and the tailstock casting will be its bearing. After the headstock is bored, the tailstock ram blank will be cut down to size, morse taper added, and threaded for the ball handle spindle at the rear.

(http://www.vtsteam.com/Lathe/BoringBar1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 01, 2018, 04:06:26 PM
But after playing around with it for a bit, I decided that I didn't like that idea. A cantilevered boring bar worked fine on the old Gingery lathe for a number of reasons that don'tapply here.

So I re-thought the whole process and decided to make a long boring bar that turned in the tailstock ram at one end, and a temporary support at the other end.

First I found a length of 5/8" rod and turned a 60 degree taper on one end. I removed the tailstoick ram and cut it shorter at the front, mostly removing the hole I had bored. Then drilled the other end with a center drill, and reversed the ram in the tailstock.

The new boring bar fits into the center drilled taper. A 5" pulley is slid onto the bar;

(http://vtsteam.com/Lathe/HeadstockBoring1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 01, 2018, 04:09:59 PM
Next I made up a temporary support at the other end and center drilled an old cast block of aluminum to take the other end of the boring bar.

(http://www.vtsteam.com/Lathe/HeadstockBoring2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 01, 2018, 04:12:42 PM
Then I drilled the 5/8" bar where the cutting tool should be, to clear both ends of the headstock when it slides.

I silver brazed on one side of that location a small piece of water pipe, to pad out the thickness for adding a set screw.

Then I filed the hole square to fit a 1/4" tool bit. And added a set screw.

(http://www.vtsteam.com/Lathe/HeadstockBoring3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 01, 2018, 04:14:06 PM
Finally this is what the whole setup looks like, so far. I slid the pulley away so you could see things better, but in use it will be close to the tailstock. The carriage has had the cross slide removed and sits behind the headstock. It will be attached temporarily and push the headstock along the ways. Making everything clear on this short but rugged lathe took a little head scratching and positioning for tool bit, and supports, but I should be able to bore both ends of the headstock for the roller bearing recesses without disturbing the setup.

(http://www.vtsteam.com/Lathe/HeadstockBoring4.jpg)
Title: Re: Building a New Lathe
Post by: PekkaNF on June 01, 2018, 04:57:13 PM
Pretty good indeed! You have it mostly sorted.

Have you considered the side loading (shift on cutting bit rotation axis) with belt tension? Probably you will move that wheel as close to tail stock point as possible and but drive on front side to bring the error to turn fintting taper.

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on June 01, 2018, 09:52:10 PM
I don't quite understand the last part of what you wrote, Pekka, but the gist seems to be worry about belt tension and shaft bend. I think things will be fine. I have a relatively thin belt, and I don't plan on horsing down on the pulleys with lots of tension. Basically they can be relatively loose in practice -- they just have to avoid slipping to a halt. The cutter and depth of cut will be small. Not a lot of resistance to the belt, so, not much tension needed.

If the initial cuts seem problematic, I can always modify the setup. There's a LONG way between the present diameter and the final diameters. Plenty of time to stop and alter. But I think we'll be okay. And of course, I've already done all this before with the Gingery lathe.  :zap:
Title: Re: Building a New Lathe
Post by: WeldingRod on June 02, 2018, 08:00:04 PM
Ah, yes.  I, too started a milling machine build when was at Rice, and had keys to the shop.  I welded and ground a beautiful square way column with two riser blocks.  My mentor gave me an old mill g machine head which I proceeded to graft big tapered roller bearings onto with a shrink fit extension.  I machined an R8 spindle, but I screwed up on the threads for the preload nut.  Still worked, though.  I don't know tha t i got the taper perfectly concentric, though.  I scratch built a brushless dc driver for a 3/4 go m9tor I took out of something.  Blew the crap out of the pass transistors twice with the brake function.  Argh.  Someday I might get back to it.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on June 02, 2018, 10:16:49 PM
This isn't a milling machine.  :scratch:
Title: Re: Building a New Lathe
Post by: PekkaNF on June 03, 2018, 06:00:00 AM
Steve, I have confidence in you, I followed the Gingery lathe build and your previous adventures. I', pretty sure that you will pull it trough with that setup with minimal problems. My rambling are more in the line of "Plan B/C", I'm eternal pessimist on my own projects.

What I ment that the margins are small on this kind of setup. I does not take much side load to bend this slender shaft that is pressed between centres and has cross drilling on the middle. Even without drive it cutting bit will make hula hoops (small) + cutting force will retard the bit a little and then you have a little drive force.

Grinding between centres illustrates this and usually (if precision is the driving force) centres are dead and drive is with separate drive plate, that rotates on it't own bearing to separate the drive as much as possible from the shaft. I relaizi that shaft grinding is a diferent process from linebooring, but setup has few parallels.

Consider this:
http://www.harigmfg.com/lectricctrs.html

Antoher thig....if the slender shaft is a bit more stable when it is on tension, vs. when it is compression. Easy to understand when you think machine ball screws, they are always pre tensioned, not only to prevent play (preload), but also to dampen vibrations and to make then more true. My memory might be failing me, but orginal Gingery setup had a boring bar in tension? Did it?

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on June 03, 2018, 12:30:16 PM
Pekka I appreciate the concern, but as I said, I think it will be fine. That's just personal estimate based on my own experience, and the fact that I'm working with the real thing instead looking at a photograph on a forum. You're free to interpret things pessimistically. Maybe I'm wrong. If so it won't be a big deal, as I've said, I'll alter to suit.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 03, 2018, 03:11:47 PM
Cutting shims from an aluminum iced tea can. These are .004" thick and 5/8" wide. I'll pack them under each side of the headstock cap before boring. I have thinner (.001") brass shim stock on hand. So if I over-bore, I can actually reduce in half thou steps.

(http://www.vtsteam.com/Lathe/CuttingShims.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 03, 2018, 09:33:40 PM
Catching up on other small but necessary chores before boring the headstock. I cast a clamp piece for the tailstock from some mixed scrap zamac sprues. I was able to use the clamp for my Craftsman lathe as a pattern since the bed and way proportions are the same on the new lathe, and I am using a Craftsman casting for the tailstock.

Using an existing part as a pattern was a little tricky. Normally I use a wood screw as a handle for withdrawing a wooden pattern. This cast iron pattern was very hard to grasp -- I tried tweezing it out with small artist's spatulas but it was too heavy and dropped back into the mold, damaging it. The metal was ready to pour. What to do? I ran back into the shop and grabbed an old hard drive magnet, and that worked well as a handle for the pattern. Quickly repairing the cavity as best I could with spatulas, I closed up the flask and poured.

Here's the result after shake out:

(http://www.vtsteam.com/Lathe/ClampCasting.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on June 03, 2018, 09:38:57 PM
After a quick hacksaw and file session to get rid of the sprue, flash and vent wires, the result was better than I expected, or deserved after damaging the mold. Actually perfectly usable copy, and after trying a securing bolt -- the head was properly trapped in the slot, just like the original.

If I'd done a better job, I probably could have picked up the part numbers, but I was happy just to get a proper fitting part after. I'll remember the magnet trick in future. :med:


(http://www.vtsteam.com/Lathe/Clamp.jpg)

Title: Re: Building a New Lathe
Post by: eskoilola on June 03, 2018, 11:21:01 PM
The hard drive magnets are quite strong and I assume they may also damage the mold when they snap on the pattern. I suppose dropping the pattern back into the mold is far more worse though.
Title: Re: Building a New Lathe
Post by: vtsteam on June 04, 2018, 08:35:39 AM
Man I'm starting to understand why Rob abandoned fora.
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 04, 2018, 11:46:57 AM
Hi
Nice work, looks like you will soon be ready for the first tests of the new lathe  :beer:
Title: Re: Building a New Lathe
Post by: NormanV on June 04, 2018, 12:28:48 PM
I miss looking at Rob's welding!
Title: Re: Building a New Lathe
Post by: eskoilola on June 04, 2018, 01:34:35 PM
Pheewwww....

Have been reading this 3 year old thread for some hours now. Enjoyed every minute of that. I am quite impatient, so You should consider this as a statement.

I actually like the boring setup for the head stock. This way it is guaranteed that the head stock will become perfectly aligned with the tail stock.

From my very short experience on machining I would suspect some vibration. Bending the rod is not an issue as one can take thin cuts and use a razor sharp tool to do that. My experience on line boring is equal to no experience. I will be following this thread as I do have a use for this kind of a setup.

How did You set this up ? I mean, how accurately does the support behind the head stock need to be aligned? I would have a lot of difficulties in getting the rod aligned with the ways (I suppose this is how it should be).

After reading Your thread I assume You know all the common tricks to dampen vibration on this setup. Probably You also know a few not so common too. Mind sharing those with us? Asking this without knowing anything about zinc alloy vibative properties.

All in all - nice and partly really funny thread. Pleasure to read. Thanks !

P.S. Sorry about the snapping magnets. I just happen to have a bunch of those hard drive linear actuator magnets and those are very attracted to anything and especially wit each other. One can hurt fingers with improper handling of those. Why do I have a lot of those ... I am an DWH specialist ... go figure.
Title: Re: Building a New Lathe
Post by: vtsteam on June 04, 2018, 05:28:22 PM
Norman, me too. I miss everything he did. Always amazing and interesting.

Eskoilola, just put something other than fingers in between magnets and what you want to pick up. You can glue sheet rubber onto one face, or leather, and vary the thickness to vary the amount of attraction. You can also transfer magnetism down a rod at reduced levels to pick things up. Lots of ways to skin a cat. If you turn the magnet on edge, and it's still attached to its backing plate, as mine was, you can also reduce the snap. I was wearing leather gloves to pick up the cast iron clamp, so I was able to ease it down that way, and didn't mind trapping a little of the glove under. I had hot metal ready to pour and did what I needed in a "pinch".  :lol:

Got 'er done. :dremel:
Title: Re: Building a New Lathe
Post by: vtsteam on June 04, 2018, 05:31:05 PM
Thanks Neubert.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 04, 2018, 05:41:07 PM
And to all......it's hundred times better to do something than theorize about what could possibly happen if you did. Discussing results before boring, is well.....boring.

Ya know, there's a wasp nest in the ceiling above the shop, and maybe while I'm cranking the leadscrew, a wasp might sting me on the eyeball, and I'd then start cranking too fast and not notice I was boring too deep, or if it's raining lightning could hit the lathe and melt the zamak at a different rate than the steel, and I'd have wished the lathe had been cast in iron.....or rubber. Or an earthquake might swallow up my whole shop before I had that headstock bored, and then where would I be? In the "other place" where I belong, no doubt.

Or I could just wait and see what happens when I actually start making a hole in the metal I want to make a hole in.  :lol:
Title: Re: Building a New Lathe
Post by: vtsteam on June 05, 2018, 09:52:45 AM
Okay, back to doing things. First we cut out a couple of pieces of scrap galvanized steel sheet:

(http://www.vtsteam.com/Lathe/Gauge1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 05, 2018, 09:55:37 AM
Then clamp them together over the lathe bed near the tailstock, and contacting both the side and bottom of the boring bar. The tab at the bottom should be tight to the front way edge. Apply a few drops of super-glue to the mating sheet edges.

(http://www.vtsteam.com/Lathe/Gauge2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 05, 2018, 10:07:11 AM
And we now have a gauge for setting the other end of the bar. This is a variation on the Gingery lathe boring gauge -- that one is a single piece gauge, and is cut to the desired center height of the lathe minus half the boring bar diameter.

In my case I had an existing tailstock of presently unknown center height that I want to match in boring the headstock, so I used a two piece gauge fabricated against the existing lathe components. No measurements involved. And it should be possible to set the other end of the boring bar to exactly the same height using this gauge, which I will keep as a permanent tool for this lathe.

Oh, also, it gives me the actual center height, by calculation. Not that I will use it to set the boring bar -- a gauge is far more accurate -- exact, in fact.

But for information purposes, the gauge measures 4.210" in height where the boring bar touches it, and the boring bar measures 0.622" in diameter there, so taking half that we get 0.311". Adding 4.210", we get 4.521" true center height. So we're on target for a 9" swing lathe - plus a whisker.  :med:

(http://www.vtsteam.com/Lathe/Gauge3.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on June 05, 2018, 10:21:43 AM
Very neat trick Steve  :thumbup:

How did you ensure that the sheets were perpendicular to the lathe ways?
Title: Re: Building a New Lathe
Post by: vtsteam on June 05, 2018, 10:24:40 AM
Wiggle 'em.

Just like calipers.

Feel for it. Feel the force, Luke.  :zap:
Title: Re: Building a New Lathe
Post by: ddmckee54 on June 05, 2018, 03:52:34 PM
Cool, you built your own version of a telescoping gage.

Don
Title: Re: Building a New Lathe
Post by: vtsteam on June 05, 2018, 09:53:29 PM
Hi Don, pattern fitting, which is what this really is, is a prehistoric method. I wouldn't mind a set of telescopic gauges, though.

Today I dug out of the depths of my tiny shop my treadmill motor and DC controller -- a "Cycletrol 150." Both bought used 3 years ago on Ebay. Both subjected to way too much moisture. I had my doubts they would work.

After finding a schematic and manual online, I tried for hours to get that motor to turn, but no luck. There were 8 DIP switches, 3 potentiometers on board and lots of screw terminals with inputs and jumpers. Nothing worked. The schematic called for a 5K ohm external pot, for the speed control, and I had squirreled away a linear I had bought for this purpose from Radio Shack before it closed. That's how old all this stuff is.

(Cyclotrol Model 15303 Manual attached below)

One obvious problem was that the red "Brake" LED was always on. I tried everything, and was about to give up, when I tried just disconnecting the 5K pot altogether. Suddenly the motor ran. I tested the pot -- it was fine, double checked my jumper wires...they were fine. Finally I tried the only other pot I could find in my electronic junk box, a 1 megohm type. Oddly enough, it worked -- after a fashion. The motor would start, and I had some control over speed.

I started to play with the onboard trim pots -- one adjusted the minimum motor speed, and one adjusted the maximum. With these I was able to adjust a full range of RPM for the speed pot. So all was working finally. Only spent all day on it! No further work on the lathe

But I really don't understand why the 5K pot the mfr. called for didn't work, while a 1 megohm pot did. I mean how could it be that far off??? I substituted back the 5K ohm pot, and the same problem returned. I even found a 10K pot in an unused piece of computer gear, pulled that out, tried it with the speed controller and again, no go.

Well, I guess I ought to just be happy it works finally. It's just a puzzle to me. But onward with the lathe.



Title: Re: Building a New Lathe
Post by: eskoilola on June 06, 2018, 10:44:52 AM
....
But I really don't understand why the 5K pot the mfr. called for didn't work, while a 1 megohm pot did. I mean how could it be that far off??? I substituted back the 5K ohm pot, and the same problem returned. I even found a 10K pot in an unused piece of computer gear, pulled that out, tried it with the speed controller and again, no go.
 ....

From experience I would say that the impedance on pin 9 (SP1) is way too high. When placing a high impedance potentiometer the voltage on pin 9 does not drop. But when the potentiometer is the specified 5K then the voltage suddenly drops. The brake light might be a part of this syndrome - it is my assumption that the light will go on when the voltage on pin 9 is lower than a given limit.

If You have a voltmeter, You could measure the voltage availble at pin 9 with the 5K pot and the 1M pot.

Since I do not have the schematic on hands I cannot give suggestions on where to seek for the fault.

For me that sounds a lot like a cold joint on emitter follower transistor collector.

The voltage in pin 9 should be really low impedance, probably something like 1-10 ohm. Now it is at least 100K or perhaps even more. The normal way to lower the impedance on a place like that is to use a simple emitter follower. I believe this is a last millennium device.

It is also possible that the voltage in the pin 9 is regulated with a beck then normal 78xx series regulator. Schematics would be really helpful and take the guess out of guesswork.  :coffee:

Edit: Actually - it could be a bad joint somewhere in the circuitry supplying voltage to pin 9. Check the joint along the trace starting from the pin 9 and see if there are any suspicious solder joints. A suspicious joint can be quite innocent looking. For example some through hole resistors can get a nice oxide layer inside the solder joint.

Another edit: Example of a really suspicious joint

(http://kirppuja.fi/Public/madmodder/IMG_0844_small.jpg)
Title: Re: Building a New Lathe
Post by: ddmckee54 on June 06, 2018, 03:26:51 PM
Vsteam:

I got an in-expensive set of telescoping gages off Ebay a couple of years ago.  The set is 6 gages and it's good for 5/8" to 6".  Best part is I didn't have to sell any body parts to afford to get it.

I wouldn't try to build a rocket engine or nuclear reactor with it, but for what I do it's good enough.

Don
Title: Re: Building a New Lathe
Post by: eskoilola on June 06, 2018, 04:05:19 PM
Snap gages are quite fun to use. I bought mine well beaten Starrets two years ago. Those are still giving consistent measures.

I have to thank mr. Booth for inspiring me to use them. I actually spent one evening just measuring diverse tubes and trying to get consistent measures. Then I bored a few steel tubes and aimed to some imaginary dimension. For some funny reason I learned to do the actual snapping my eyes closed just listening to my fingers. At the end of the day I was actually able to get 5 very similar results in a row.

However, in this particular context I would also prefer using some sort of a jig. Using snap gages to measure the boring bar height would be horrific and trying to set it up horizontally next to impossible using the gages. I suppose that jig should also be used in the listen-to-your-fingers mode.
Title: Re: Building a New Lathe
Post by: vtsteam on June 06, 2018, 06:59:38 PM
Thanks for the electrical troubleshooting info Eskoilola, I'll check that later tonight.

Thanks Don, I may get some as soon as I get everything else I need to get the lathe going.

I had to work today, so very little time for the lathe, except I did braze a bit of scrap 1/4" water pipe to the treamill motor's base to serve as a hinge when mounting it. I was afraid to arc weld it, in case the arc affected the motor's permanent magnets. Wasn't sure on that, but figured better safe than sorry. And I didn't want to overheat anything, since there is a plastic end cap and brush holders, so just a few blobs of braze and then a dunk. But it should hold.

(http://www.vtsteam.com/Lathe/MotorHinge.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on June 07, 2018, 02:45:35 AM
You are brave Steve!

I'd have brazed that pipe to another bit of plate then bolted it to the motor foot.

 . . . But then I'm a coward
Title: Re: Building a New Lathe
Post by: vtsteam on June 07, 2018, 07:58:21 PM
Hardly, Andrew, from what I've seen you take on!

After work today I welded together a U-shaped bracket out of 3/8" x 1-1/2" hot rolled steel to take the motor pivot. I made it extra long because the belt I have for the initial boring job is a bit too long. Even so, after welding I realized I wouldn't be able to bolt it to the lathe bed because it interferes with existing cross bolts. Instead I'll just temporarily bolt it vertically on the bench and I will have to bolt the lathe down as well.

I'll cut it shorter and measure for a new belt, once the boring is done, and move the motor bracket to the headstock end.

Only a couple more jobs left before boring -- attach the headstock to the carriage with a piece of angle Iron, and attach the left side boring bar support at the right position, checking with the gauge I made. The support was bolted together with slots for adjustment of the boring bar position.

Oh, one more thing....I think I'm going to add a "ram" to it -- basically just a bolt with a center-drilled head, which will screw into the support block. A stop nut will lock it. The boring bar end will ride in the bolt head, not in the block, as I have it now. I will be able to adjust and snug the bar that way, if needed.

Getting close to boring day -- probably the most important single event in this whole process, and the one that, when finished will turn this glorified dog's ladder into a lathe.
Title: Re: Building a New Lathe
Post by: awemawson on June 08, 2018, 02:25:46 AM
Hardly, Andrew, from what I've seen you take on!


And it's all starting again Steve :bugeye:

That Beaver CNC lathe is being picked up on Monday, all 6.25 tons of it. It may well not be delivered to me the same day as its coming as a 'part load'

Excellent progress with yours and good luck with the boring  :thumbup:
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 08, 2018, 06:30:05 AM
when finished will turn this glorified dog's ladder into a lathe.

And what a nice ladder/lathe it will be :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on June 09, 2018, 04:04:04 PM
Thanks Andrew, Neubert!  :beer:

I'm back to retirement as of today, so on with the show....

I just realized I also needed a ball handle for the leadscrew to traverse the headstock over the boring bar. So, I found some old propane valves that I'd removed from tanks used for other purposes (like building the tiny furnace). Popped them into a crucible and put it in the tiny furnace.

(http://www.vtsteam.com/Lathe/BrassParts1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 09, 2018, 04:10:43 PM
It surprised me how quickly the valves melted -- I barely had time to ram up a mold. This is with a purely atmospheric propane burner I built -- quite small actually. I did augment the draft with a length of stovepipe perched on top of the furnace lid.

The melt wasn't quite behaving right -- a little pasty, by the time I was ready to pour, so I guessed I'd lost some zinc in the long time it took me to make up the mold.. I decided to drop in a couple of the thin frozen zinc spills from prior pours-- less than an ounce I would guess. And yes the melt became nice and fluid soon after. I skimmed and poured.

Here's the result when I separated the flask. Besides the ball handle, I also cast a locking lever for the tailstock ram. and a very small oil dipper that it also takes. That last one didn't quite fill with brass -- you can see the impression of the post at the end is not quite filled.

(http://www.vtsteam.com/Lathe/BrassParts2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 09, 2018, 04:15:18 PM
Here they are liberated from the sprue, and rough cleaned. I'll probably just drill the oil dipper, and add a bit of brazing rod for its post. Surprisingly easy to cast some useful bits in brass today. Very pleased!

(http://www.vtsteam.com/Lathe/BrassParts3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 10, 2018, 10:02:28 PM
Today I drilled the ball screw to fit the leadscrew, and added a set screw. The carriage ran a little tight at first, but I had not tightened the screws adequately on an aluminum bed extension that serves as an attachment point and heat sink for a stepper motor -- should I decide to go with the electronic leadscrew I worked up a couple years ago. Anyway, the extension also carries the left side leadscrew bearing, and it turned out that the extension was rocking slightly and throwing the bearing out of line.

What was really needed was countersinking its attachment bolts, and fully tapping the corresponding blind bed holes -- which had never been fully bottom tapped. Once this was accomplished, the extension could be firmly bolted in place, and the leadscrew and new ball handle drove the carriage sweetly along the full length of the lathe.

Next to receive attention was the headstock. It also bound, about halfway along the ways. It slides on the inside edges of the two way pieces, while the carriage rides on the outside. I finally traced the binding to the fact that the headstock's retaining plate was contacting a slight high spot on the heavy steel bed bearers.

To solve that, I milled the retaining plate on the binding side about 0.030" narrower so it wouldn't contact the bed rails, just the ways. The headstock then slid sweetly along the full length of the lathe.

Finally I drilled a couple holes in short length of angle iron to attach the headstock to the carriage. Then transfer punched those locations and drilled and tapped the two moving parts. Finally the carriage and headstock are connected, and the leadscrew now drives the headstock down the ways. No binding, and the ball handle moves everything easily. I adjusted the two gib screws under the headstock, and hit them with some Loctite.

All that's left to do before boring is attach the left side boring bar support, fasten down the lathe and the motor bracket, connect the speed controller, and ......go.
Title: Re: Building a New Lathe
Post by: vtsteam on June 11, 2018, 09:34:37 AM
The cross slide has been removed, and the headstock has been screwed to the carriage temporarily with a bit of angle iron.

(http://www.vtsteam.com/Lathe/HeadstockAngleIron2.jpg)
Title: Re: Building a New Lathe
Post by: NormanV on June 11, 2018, 10:01:44 AM
Steve, when do you sleep?
Title: Re: Building a New Lathe
Post by: vtsteam on June 11, 2018, 10:31:37 AM
Heh, Norman, any time someone turns on a television, during company meetings while employed, when dragged to any recent movie involving male superheros or Johnnie Depp, while visiting friends for dinner if the conversation turns to Apple products, cell phone plans, or health issues, etc.  :)
Title: Re: Building a New Lathe
Post by: krv3000 on June 11, 2018, 05:56:34 PM
 :D brill

Title: Re: Building a New Lathe
Post by: vtsteam on June 11, 2018, 09:41:23 PM
Thanks Bob!  :beer:

For an adjustable pivot, I faced off a bolt and center drilled it. Tapped the support block and added the bolt. The boring arbor fits there, and I can take up the slack with the bolt. The nut is for locking it.

(http://www.vtsteam.com/Lathe/BoringPivot.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 11, 2018, 09:42:39 PM
Setting up the bar with the gauge made previously:


(http://www.vtsteam.com/Lathe/BoringSeting.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 11, 2018, 09:44:33 PM
And finally, boring the headstock!  :ddb:

Uhhh....this is going to take awhile.......


(http://www.vtsteam.com/Lathe/Boring.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 12, 2018, 02:25:17 PM
Verrry slow going. I have to re-sharpen the HSS bit every pass. Unfortunately, I have to enlarge the diameter by 0.5", just for a clearance bore. I'm probably only cutting .010" per pass.

The recesses for the bearings are larger than the clearance bore. The are not full depth, however, so they should go more easily.

Also, I'm still at an interrupted cut stage, and there are undoubtedly sand inclusions in the cast skin in the bore. Once that's all gone, and the interrupted cut is over with, I hope the bit will stay sharp longer and things will go more quickly.
Title: Re: Building a New Lathe
Post by: NormanV on June 12, 2018, 05:26:04 PM
I am confused by your problems. When I bored the tailstock of my lathe, similar setup, I was hand cranking it and had no problems with tool sharpness. I was particularly surprised as I was machining the split collet (steel) at the same pass and found it a bit tight. When I examined it afterwards I found that the collet had managed to move between each pass of the cutter but fortunately on the last pass it all seemed to be ok. I can't show a photo as everything is packed up for an imminent house move.
Title: Re: Building a New Lathe
Post by: vtsteam on June 12, 2018, 10:38:30 PM
Norman, BIG difference between cast aluminum and cast Zamac, or even steel and cast iron. I too found boring the aluminum headstock and tailstock castings for my Gingery lathe a piece of cake, by comparison.  They were also a lot smaller radii than this one where I'm boring a clearance hole over 2" in diameter, not to mention the even larger recesses for roller bearings. That alone means more much more metal to take off than a tailstock, and I have a full half inch to go on the through bore -- not a close bore to start.

Both metals were sand castings, and I can't exactly explain why if the holes had been the same size this one would be so  different in cutting ease than the other, but the fact remains, they are.

One noticeable difference to aluminum I've found is that the tool grind angles have to be much sharper with Zamac because it is both slippery and very very tough, and the necessarily fine edge needed to cut it doesn't last well. Zamac machines beautifully, but not necessarily easily, and I'm working with a home concocted Z-12, not commercial quality. Filing and hacksawing also are noticeably more difficult than with sand cast aluminum, and those dull quickly as well, on the same types of jobs I would do with aluminum.

This particular casting really wants a carbide tool with sharp angles and top relief, but I don't have anything suitable that I can use with this boring bar. So it's slow going with HSS. And frequent re-sharpening. I do think that when the skin is fully removed from the bore (it was quite irregular and there are still patches of as-cast skin) that I won't have to sharpen as frequently.

No problem, really, Norman,, I'm patient, and I'll get there. I hand scraped the ways over several days, and I don't see that it's a big deal to take it slow boring either. All part of the game...

Title: Re: Building a New Lathe
Post by: awemawson on June 13, 2018, 01:38:34 AM
Steve, could you possibly have remaining sand inclusions in the skin that are dulling your tip?
Title: Re: Building a New Lathe
Post by: vtsteam on June 13, 2018, 08:08:43 AM
Definitely Andrew, what I was trying to say., last two posts The bore was dirty and irregular shaped if you go back to my original casting photos, necessarily -- it was a difficult casting to get everything right.

Because the bore is irregular and has hollows, I can't just get rid of the entire skin in one cleans swipe -- it will take removing another quarter inch of material to get completely rid of it. One small patch will dull HSS instantly.

But I also do think that this Zamak 12 is really recalcitrant anyway, by nature. You can get a good surface finish with carbide, but it's really tough on ordinary tools -- noticeably so on hacksaw blades and files. And chisels -- I did try chiseling off some of the flash. Nothing like as easy as even mild steel. I'd far rather hacksaw a 1/2" thick slab of steel, than the same size slab of Zamak. I think it's the combination of slipperiness, with high tensile strength, yet relatively soft qualities. It's both sticky and slick, and nothing less than a perfect edged tool tends to plow it to the side rather than chip it off. Or just slide over the cut. It is nothing like brass -- though you would think it's similar. The last thing you'd want is to stone back the inside edge of a drill. Cutting tool angles have to be more acute not to just ride over the cut.
Title: Re: Building a New Lathe
Post by: vtsteam on June 13, 2018, 04:53:56 PM
I was curious to see how much skin was left, so I decided to pull the bearing cap off and have a look. Quite a lot, since there were hollows in the core impression. 

So I got out a Dremel and chucked up a carbide burr, and went at all the grainy looking areas I could find. When I put the cap back and resumed boring, I noticed a definite cutting improvement. I'm still sharpening the bit frequently,  but not as much, and the cuts are a little deeper and more consistent, end to end.

Next improvement I'm contemplating is making a new 3/4" boring bar to replace the 5/8" one I started with. There wasn't clearance for anything bigger to start, but now that the bore is much larger I can move up in size. A larger bar will mean I have to also bore the pulley to fit it, but I judge there's enough hub to do that.

3/4" would be the limit for hardware store pulleys though.

Getting there.....
Title: Re: Building a New Lathe
Post by: awemawson on June 13, 2018, 04:58:36 PM
Can you not re-arrange so that the pulley is at one end, and just turn down the bar to suit the pulley bore ?
Title: Re: Building a New Lathe
Post by: vtsteam on June 13, 2018, 05:55:29 PM
I could. The pulley is located at  the very end of the bar, now -- just a tiny bit ahead of the 60 degree tapered end that fits the center drilled hole in the tailstock ram blank. So yes, Andrew that would be do-able. Might take you up on that idea.  :nrocks:
Title: Re: Building a New Lathe
Post by: awemawson on June 14, 2018, 12:38:18 PM
. . . .no charge . . . . :lol:
Title: Re: Building a New Lathe
Post by: vtsteam on June 14, 2018, 02:32:14 PM
Before I did make a new bar, I decided to cut down one of my 1/4" indexable turning tools (from a cheap set that I've never found replacement inserts for) to 1-1/2" long, and put it into the boring arbor.

Man what a difference! It really chews through the sand cast Zamak. Not a pretty cut, but I can take .030 off the diameter in a single pass, no sharpening, at twice the RPM and a decent feed. I was starting to get down about all the sharpening I needed with the HSS. Well, this is a job for carbide only. Obviously the insert and angles aren't ideal for a clean cut, but at least the end is in sight for this clearance bore. Phew!
Title: Re: Building a New Lathe
Post by: vtsteam on June 15, 2018, 06:11:20 PM
As I get closer to finished bore size, the extension of the tool bit has increased to the point where it's moving slightly despite the set screw. So today I hunted up an old piece of cast aluminum sprue, and turned and milled up a little boring head for my arbor, just a 0.1" smaller than the present bore.

This should make the next few cuts out to finished size a lot easier, and though it presently fits the 5/8" arbor, I can open it out for a 3/4" arbor later -- which will be necessary for doing the bearing recesses.

By starting with 5/8" I'm able to keep the tool bit a little longer inside the shell for better support, until the bore is larger and I can switch to a longer tool. And this time the tool is held by two set screws, so I don't think movement will be a problem... at least for awhile.

(http://www.vtsteam.com/Lathe/BoringArborHead.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 15, 2018, 10:32:10 PM
It's working very well, much deeper cuts but necessarily slow feed. Otherwise the driven pulley slips. Since I can't fit a carbide tool in the small space, it also means I'm back to HSS, and frequent sharpening. But progress.  :dremel:

This is probably unecessary at this point -- the spindle is about one and a quarter in diameter, and I'm nearing 2" on the clearance bore. But I had it in mind to make it to 2.125" and I haven't given up on that....for no apparent reason.
Title: Re: Building a New Lathe
Post by: Homebrewer on June 15, 2018, 11:37:17 PM
So, it looks sort of like you're using a fly cutter like tool, mounted on a mandrel.

I have been watching this thread with great interest because if I ever get out of this apartment and into a house, I plan to go through the Gingery book and build a lathe similar to yours.  Following your thread has both given me ideas as well as validated some others that I'd give consideration.

Sent from my SM-G950U using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on June 16, 2018, 12:38:03 PM
Thanks very much Homebrewer. :beer:

Yes, I've made a few similar over the years -- the first was back 13 years ago when I was adding a milling attachment to the Gingery lathe -- I didn't have a milling machine then, so the fly cutter with an arbor mount, instead of the usual stub, was used to level a new milling and boring table:

https://madmodder.net/index.php/topic,8191.msg88064.html#msg88064

I personally think building a Gingery lathe is the best possible kind of machinist self-education, because you're really starting from scratch, and you are forced to use historical methods, hand work and ingenuity to get to the finished product. Buying a lathe is fun because you can get started right away, but it kind of short circuits that education. Turning and threading are all a lathe can teach you -- at least out of the box. There are probably fifty more things you learn building one from scratch.

For me, building that lathe led to many things, including wonderful employment opportunities, that I probably wouldn't have had otherwise. Also, it's incredibly rewarding to build it. In fact, no project I've ever built using that lathe equaled the thrill of building it in the first place.

You're on the right track if that appeals to you. I'll always be grateful to David Gingery for that little orange book I just happened to pick up one day.
Title: Re: Building a New Lathe
Post by: awemawson on June 16, 2018, 12:57:21 PM
Many many pre-war (I mean 1939-1945 war) models of engines etc were made with very basic tools, the lathe often being treadle driven, and the models were of a very high standard. When I was involved with the SM & EE  I was amazed at the workmanship of some of those early models in their collection.

To have a milling machine in a home workshop was unheard of, but vertical slides to mill on the lathe were not uncommon.

I agree Steve - making things with limited resources demands imagination and determination but it CAN be done  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on June 16, 2018, 05:28:33 PM
Done with the clearance hole. Now starting the bearing journals.

I believe these need to be 2.441" in old measurement. This is going a fair amount easier with only an inch to bore for depth. The arbor mount cutter is working very well. Glad the other is over with!  :Doh:

(http://www.vtsteam.com/Lathe/BoringBearingJournal2.jpg)


(http://www.vtsteam.com/Lathe/BoringBearingJournal1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 17, 2018, 01:12:47 PM
Getting closer to journal size, it was time to make a bore gauge. I found a scrap piece of aluminum 2.5" in diameter. The bearing measured (on my calipers) 2.4395". Not that they are accurate to a half thou, but I've been using it consistently, so parts should match.

(http://www.vtsteam.com/Lathe/BorGauge1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 17, 2018, 01:18:17 PM
I turned the gauge to 2.440" on one side and 2.430" on the other. Sorry I don't have any photos of turning, but if you're interested, John (Doubleboost) posted a fine video on youtube awhile back showing the process of bore gauge making (his ER32 lathe chuck video).

I'm adding an additional touch to suit my particular headstock boring setup here -- first drilling the gauge 3/4"

(http://www.vtsteam.com/Lathe/BorGauge2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 17, 2018, 01:20:49 PM
Then I sawed a slot close to the finished diameter on my bandsaw. I probably could have left it there, but decided to clean up the slot on the mill:

(http://www.vtsteam.com/Lathe/BorGauge3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 17, 2018, 01:24:42 PM
And here's he finished bore gauge. The slot allows me to drop it down over the boring arbor and test the bore without taking apart my setup. I was a little apprehensive putting a slot in the gauge, in case there were internal tensions that would change the OD's, but measuring after slotting (and letting the gauge cool) showed the diameters were still spot on.

So I stamped both sides of the gauge with their dimensions, and we're ready to continue boring the journals.

(http://www.vtsteam.com/Lathe/BorGauge4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 18, 2018, 05:14:00 PM
And after boring all morning, we have a bearing journal!  :ddb:

Phew....!!


(http://www.vtsteam.com/Lathe/Journal2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 18, 2018, 05:17:17 PM
The gauge worked perfectly in sneaking up on the final diameter. The final fit is nice and close, and I'm happy. Hope the other one comes out as well.

(http://www.vtsteam.com/Lathe/Journal1.jpg)

One of the things to remember is that this type of boring has no actual lathe adjustment or graduation at this stage in the construction. It's all a matter of moving the cutting bit out of the boring bar small amounts at a time and re-tightening the setscrews. So it feels like quite a victory to hit the diameter right on the money.
Title: Re: Building a New Lathe
Post by: awemawson on June 18, 2018, 05:19:27 PM
Excellent Steve - that must be quite a relief to complete this phase  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on June 18, 2018, 06:29:32 PM
Well, one more journal to go, but the first one done means the end is in sight.

For those who haven't tried this: a little spring in the boring arbor is helpful in getting the final diameter right. It never cuts to full depth on first pass. For instance, if I set the boring tool out 4 thousandths the first cut will be maybe 2 thou (4 for diameter), the second cut one thou more (2 on diam), and the third cut maybe a half (one thou on diam) , and so on, until you reach the chatter point. So if you play this right by advancing the tool just a little past final size you can ease right down to where you want it in very small steps without resetting the tool, testing each pass as you go with the homemade gauge. When it just fits, you're done.

Rigidity is a plus in a lathe, but you can work with a less than perfect setup to get the results you want. It just takes more time, and understanding. Since this is a one-off situation (the finished lathe will be a much more rigid boring platform) boring the headstock before it is fixed in place with a 24" long  boring bar is a little tedious, but certainly tolerable, considering this kind of setup won't be needed again.
Title: Re: Building a New Lathe
Post by: vtsteam on June 18, 2018, 10:25:58 PM
I was asked about chatter. I've debated whether to answer. It's easy to make generalizations, and it's always the specifics that matter. You have to be observant and, well, flexible.

In a small lathe or flexible boring operation, yes chatter happens. But it's not necessarily a negative. Chatter is nature's way of telling you to slow down. Or sharpen your tool angles differently to suit the material. Or increase the feed. Or reduce the tooth profile. Or check that some part of your setup is starting to get loose. Or that you need to increase pressure in your gib screws. Or that you're too impatient. It's an alarm bell. You shouldn't get mad at it. It's there to help you do something different than you're doing.

It's something to figure out. It's something to make you a better, more skillful and knowledgeable operator. It's a set of instructions for lathe design. If things work out perfectly, you don't learn anything.

The first thing I produced after building my Gingery lathe was chatter.

Then I learned more about tool sharpening.
Title: Re: Building a New Lathe
Post by: awemawson on June 19, 2018, 03:42:37 AM
When pressing a bearing into a close fitting journal a LITTLE bit of chatter marks on the bore is a distinct advantage. The  tight fitting bearing will slightly deform the ridges, and if you are using Loctite the troughs give it somewhere to sit without being wiped off.

Title: Re: Building a New Lathe
Post by: vtsteam on June 19, 2018, 08:16:35 AM
Intetesting, Andrew. I had clean cuts on the joutnal, and I never did switch to a 3/4" bar. I would have,
though, if chatter had been present near the end.

I didn't intend a press fit, also. The bore gauge was about a half thou oversize, according to my cheap caliper. And the final fit felt close, but not tight. I haven't done tapered roller bearings before, and this is a split housing anyway, with shims present, so a drive fit didn't seem necessary. I'm assuming, that tightening up on the axial nuts in a close fit journal is sufficient pre-load, and bearing retention for the purposes of this lathe.
Title: Re: Building a New Lathe
Post by: PekkaNF on June 19, 2018, 12:34:38 PM
.... I haven't done tapered roller bearings before, and this is a split housing anyway, with shims present, so a drive fit didn't seem necessary. I'm assuming, that tightening up on the axial nuts in a close fit journal is sufficient pre-load, and bearing retention for the purposes of this lathe.

Exactly. Idea of just a retention is good. No matter how good we hobbyis are, we still strugle to make bearing seat more round than bearing is. Tight fit is the professional way, when close to nominal loading is used, but then bearing seat must be made and measured to accuracy, that is pretty much out of reach. And because of modern glues no need to. Mechanical retention is the other good choise. We can fiddle with shims, nuts and stuff way longer than it would be practical in a professional seting.

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on June 19, 2018, 01:14:00 PM
Thanks Pekka!  :beer: The only iffy part in this whole construction for me was going to be using tapered roller bearings. Plain bearings I'm very used to. I'm very happy with how close the fit is on the gauge, at least. It feels proper for the job. Now if I can just do the same for the other journal, everything else on this lathe will be a piece of cake!
Title: Re: Building a New Lathe
Post by: PekkaNF on June 19, 2018, 02:30:37 PM
Taper roller bearings are very good choice to this aplication, unless very high speed is needed (then angular contact bearings would be better).

Taper roller bearing arragement is whole lot stiffer than same size ball bearing set. You have less wiggle room with taper rolle bearings. You may need to rotate the spindle and force it one way and then another. Tighten loading nut until spindle stops rotaing (under motor or manual power) and then wiggle/pound spindle a little with soft mallet until spindle rotates even. It is very important that spindle turns close to constant torgue, this will tell that spindle/housing is concentric. Repeat until no play (and spindle can hardly turn, but turns with contant power) and leave glue to set. This should force bearings to locate as concentric as possible. After glue is set (for outer rings), it is time to adjust play (or slightest preload) for testrun. This has worked for me, sometimes the spindle would refuse run right and I had to take it all appart and assemble parts in diferent orientation. Shims are very wedgy and all nuts run askew.

Pekka
Title: Re: Building a New Lathe
Post by: krv3000 on June 19, 2018, 04:50:44 PM
 :) :) :)
Title: Re: Building a New Lathe
Post by: vtsteam on June 19, 2018, 09:07:18 PM
Thanks Bob, Pekka  :beer:

This journal is going slower than the other...must be where there was some sand inclusion. I can't see anything, but I have to sharpen the bit after every second bore increase, I'm quitting for the day, there's 0.300" left to go, and MAYBE I'll get through that tomorrow.  :whip:

Next time I do anything remotely like this again, I'll use a baked sand core in a core box instead of a greensand core, and shape it with journals in place, and a LOT closer to finished bore in size. I chalk this LOOOONG boring, boring session up to a few years of forgetting about what I used to do. Oh well, almost done.
Title: Re: Building a New Lathe
Post by: vtsteam on June 20, 2018, 06:38:03 PM
Well Finally! I got it done.   :med:   Bearing fit test:

(http://www.vtsteam.com/Lathe/BearingTest.jpg)
Title: Re: Building a New Lathe
Post by: Homebrewer on June 20, 2018, 06:52:30 PM
Bravo!!  With the paint, it looks like a professional job!


I am curious though; do you plan for any bearing covers to keep swarf out?

Sent from my SM-G950U using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on June 20, 2018, 06:57:47 PM
Yup, bearing covers, BUT I'M NOT BORING THEIR RECESSES ON THE LATHE WITH A 24" LONG BORING BAR AND HSS TOOLS!! :bang:  :bang:  :bang:

I'm going to use my mill, and a brand new genuine carbide tipped boring head I received in the mail!  :med: .

 :ddb: :ddb: :ddb:
Title: Re: Building a New Lathe
Post by: Homebrewer on June 20, 2018, 08:15:27 PM
Had enough of the Gingery line-boring have you?

Sent from my SM-G950U using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on June 20, 2018, 10:58:39 PM
Nothing wrong with that. I met my match with 2 inches of sand entrained Zamak vs hss.
Title: Re: Building a New Lathe
Post by: awemawson on June 21, 2018, 02:27:48 AM
But the result is splendid Steve, as already said, it really looks the part in its best black coat  :thumbup:
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 21, 2018, 03:01:06 AM
Nice work, it really starts looking superb  :ddb:
And nice to see how line boring can be done, since i have to bore out the pivot blocks on my bandsaw  :Doh:

Title: Re: Building a New Lathe
Post by: vtsteam on June 22, 2018, 09:37:20 PM
Thanks guys!  :beer:

Catching up on house chores for a day. So I've been out of the shop.

I think the next thing to do will be cast a spindle pulley. The spindle necks down for a few inches at the left end, and the threads and retaining nuts are at the bitter end. So there's no way to put tension on the bearings (and therefore install them) until there's at least a sleeve (or extended pulley hub) on the left to bear against the leftmost roller bearing and put pressure on the assembly.

The spindle is a force fit in the bearings, so nothing is assembled yet.

Might as well be a pulley, then. Likely a toothed belt, but I haven't decided on the exact type yet, nor the size of the pulley(s). The treadmill motor is rated at 2.5hp @130 DCV 18A @ 6700 RPM nameplate. but I doubt it will run anything like that speed, from experience. Or HP. That must be no-load speed. I had no trouble boring at ~100 RPM  w/ a crude 5" to 1.5" vee belt reduction.
Title: Re: Building a New Lathe
Post by: vtsteam on June 23, 2018, 06:39:23 PM
I'm thinking XL Belt, 18T on the driver and 90T on the driven pulley.  Those are two easy numbers to do on my spin collet, lacking a dividing head, since it does degrees. I should get about 1000 RPM top without a change in the driver pulley.

That pulley would be 5.68" diameter. So I can make a 6" pattern. Aluminum, this time, for easier notching.
Title: Re: Building a New Lathe
Post by: vtsteam on June 23, 2018, 08:47:08 PM
Raining today, and had to prepare for my daughter's birthday, but I managed to make the pulley pattern, which I turned from poplar on the Gingery lathe. Rain predicted for the next few days.

(http://www.vtsteam.com/Lathe/DrivenPulley1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 24, 2018, 10:04:16 AM
I'm going to try casting today between rains, if I can. This morning I found an older driver pulley pattern and turned up a new steel core for the driven pulley. These will stay in the mold. The tapered ends allow easier positioning.

(http://www.vtsteam.com/Lathe/DriverPulley1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 24, 2018, 12:09:08 PM
The sun came out for a bit, so I quickly rammed up a mold a melted a pot full of aluminum. It took a false cope and smoking the core piece over a candle, but otherwise a pretty simple job. Here's the shake out:

(http://www.vtsteam.com/Lathe/DrivenPulley2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 24, 2018, 07:47:01 PM
After cleaning up both sides, boring for an arbor and adding a setscrew, turning the blank down to the needed 5.684" on the Craftsman lathe.

(http://www.vtsteam.com/Lathe/DrivenPulley3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 24, 2018, 07:48:56 PM
The finsihed pulley blank, ready for toothing, and then final boring to fit the spindle.

(http://www.vtsteam.com/Lathe/DrivenPulley4.jpg)
Title: Re: Building a New Lathe
Post by: tom osselton on June 24, 2018, 10:08:42 PM
That is a nice looking casting.
Title: Re: Building a New Lathe
Post by: vtsteam on June 24, 2018, 10:21:37 PM
Thanks Tom. How is your casting going? I remember you really had a nice set up.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 24, 2018, 11:39:20 PM
I'm thinking about a cutter for the pulley teeth. Normally I'd do another fly cutter with a lathe tool as a single point. But I'm worried about my spin collet holding. It's an old 5C type, and I remember that with past gear cutting attempts, that I had problems with it slipping.

The vibration of a single tooth cutter and multiple passes is something I'd like to get away from, if possible. It seems like cutting 90 teeth without a single mistake is a fairly difficult proposition (for me, not you reading this!) , but I'm of course going to rush in anyway.

I'm going to have to keep my wits about me as there is a 36 hole disk, with a ten hole "vernier" to yield 360 parts. This means I will have to cut once, then peg the #4 hole, cut, peg the #8 hole, cut, rotate disk one and peg the #2 hole, cut, then #6 hole, cut, rotate disk one, etc. Also advancing X. If I have a multi tooth cutter, and if I can get away with a single pass, no Y traverses. Otherwise, multiple Y moves, then return. Many chances to ruin the blank.

So that's why I'd like a multi tooth cutter.

I have in mind the way I want to make one, using the lathe to first turn the profile, then milling teeth somewhat like I made the Acme tap, a long time ago in this lathe thread. I just have to research the angles and settings I will need to get there. The depth of tooth and diameter of the tool stock will determine how many teeth I can have -- I'll probably use that 1-1/8" ground stock that Lester sold me as "cold rolled". Beautiful stuff to machine, and I suspect it may be really drill rod and hardenable. If not, I have some real Kasenite as backup.

Too late to noodle it out tonight, but I hope to have a plan tomorrow....
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 25, 2018, 05:35:39 AM
very nice casting quality.
Mine often gets porous and/or often ends up being to soft for turning in the lathe.
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 09:04:27 AM
Thanks Neubert.  :beer: If too soft, it probably means you're using extrusions or other unknown scrap. Try using only aluminum castings for scrap. They have a high silicon content.

Porosity means different things to different people. Occasional very tiny bubble dots (needing magnification to see), are usually the result of dissolved gas -- often ascribed to melting in steel or iron crucibles. But many scrap castings have steel in them already (pistons for instance have internal steel reinforcing clips) or rust washed over them from outside junkyard storage, used motor oil sludge, varnish, piston rings, etc. so it's pretty much impossible to avoid ALL ferrous contamination unless you're using virgin ingot material and a non ferrous crucible. Or you can add a clay and sand liner to a steel or iron crucible. I don't usually bother doing that for my own aluminum castings, and nothing I've built has fallen apart yet. But to each his own in that department -- many internet casting discussions go back and forth repeating the same technicalities, discuss de-gassing, etc. Not many using involved methods actually build much of interest to me or detectable superior quality from what I've seen. But again, the game is the important part, not necessarily the result.

If by porosity you mean bigger bubbles and hollows, the cause is often too moist greensand, or failure to skim the melt, or some other sand contamination. Pouring too hot, is also a cause. Unless you're pouring super thin castings, or lost foam, aluminum should just be fluid, in my opinion, and not super-heated. Venting with a wire can help fill difficult cavities, though I often forget to, and usually things work out.
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 12:36:26 PM
I've spent a good part of the morning thinking about XL timing belt profiles in order to make a cutter, and there's just no solid info on the likely tooth shape for a pulley the diameter I'm shooting for.

For making a cutter, there's the old grind it and check against an existing pulley method, more or less okay for a fly cutter, but I'm hoping to turn a profile. I do have info on the straightened belt tooth profile (rack), but that doesn't tell you what the pulley's curve will do to it.

First thoughts: straight belt profile shows a 25 degree offset from vertical for the bevel. Since I'm bending things 4 degrees per tooth in a 90 tooth circle, Maybe I should split the difference and call it a 2 degree reduction in the angle, so say 23 degrees for the pulley bevel(s).

Then  there's the width of the bottom of the tooth next. Straight line belt shows .054" there. Does it compress and shorten any? Probably. How much  on a 90 tooth circle? I don't know.

Finally I just decided to go with the plain rack proportions for the cutter -- 25 degrees, and .054" tooth end width, and .050" depth. And just file the slight tooth radii. It IS for a rubber belt after all, not solid gears. We'll try the KISS method and see how S that turns out to be.....  :loco:

(http://www.vtsteam.com/Lathe/XLCutter.png)
Title: Re: Building a New Lathe
Post by: awemawson on June 25, 2018, 01:06:02 PM
John Stevenson did a treatise on cutting XL pulleys - I think his web site is still up and kept alive by his son Adam.
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 01:40:44 PM
Can't find the site. Tired of research anyway, the day's a waistin'. Out to the shop......
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 25, 2018, 03:31:22 PM
Hi
Yes i have been using all sorts of scrap, but later i have mostly used alu rims from a friend of mine that have a auto repair shop.
My crusible is made of stainless steel.
Most times i have been casting stock materials in tin  cans, but i think you hit my problem with porosity (bigger bobbles) i do tend to pour quite hot, but recently i have bought my self a pyrometer, so i am hoping that it can help with the problem.
The skimming i would say is fine.

 :thumbup:
Title: Re: Building a New Lathe
Post by: tom osselton on June 25, 2018, 05:10:22 PM
Thanks Tom. How is your casting going? I remember you really had a nice set up.  :beer:
I’d have to dig it all out right now it is packed away in the storage shed I bought to help clear out the garage when we finished off the inside and moved the machines in. I do have a lot of aluminum and brass to melt though. The quad is blocking the entrance of course with a dead battery. :doh:
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 05:31:31 PM
Hi Neubert, I don't have a pyrometer. I just watch the melt and when the pieces start to break down I give it a light stir with a 1/4" rod to feel if everything is melted and then skim and pour. For me, as soon as it's ALL liquid, it's ready. Like I said, lost foam or super thin castings might need a little more heat, say 1 minute.  :dremel:

Tom, I know the feeling exactly -- there was a delay of 2 years in this thread, when all my machining stuff was buried under other house project tools, materials, etc. Feels good to be back at it, after taking care of other necessary tasks.  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 05:53:07 PM
Well after all that blather about a multi-tooth cutter, I got impatient, and just ground a small lathe tool by hand with 25 degree angles, locked my calipers to .054", squinted as best I could at the tip, by comparison, and called it done. I installed it in the very same cast fly aluminum cutter I had bored out the headstock with, bolted down the old 5C spin indexer to the mill table, and hoped for the best.

(http://www.vtsteam.com/Lathe/DrivenPulley5.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 05:53:51 PM
In action:

(http://www.vtsteam.com/Lathe/DrivenPulley6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 05:55:11 PM
Finished pulley. Amazing....nothing went wrong!   :doh:

(http://www.vtsteam.com/Lathe/DrivenPulley7.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 05:55:49 PM
And the belt even fits.  :zap:

(http://www.vtsteam.com/Lathe/DrivenPulley8.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on June 25, 2018, 06:05:25 PM
It's ok until the phone rings as you are counting off sectors on your dividing head - ask me how I know  :ddb:
Title: Re: Building a New Lathe
Post by: vtsteam on June 25, 2018, 06:23:55 PM
Andrew I don't need an excuse to do that.

Besides the 0,4,8,2,6,0 counts, this spin collet had a devilish gotcha waiting in store for the first mental lapse: the holes didn't line up exactly with the numbers -- particularly the 2 -- I nearly put the peg in the 1 hole a number of times, especially since it is the second hole, in a numbering system beginning with zero. But some little birdie somewhere above my noggin said "STOP..... not there....third hole" and I re-set the peg. A miracle this came out, first time.


HEY, and typical.....I accidentally hit modify instead of reply for your post.  Glad it was 90 tooth instead of 91!
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 25, 2018, 07:13:59 PM
Hi Neubert, I don't have a pyrometer. I just watch the melt and when the pieces start to break down I give it a light stir with a 1/4" rod to feel if everything is melted and then skim and pour. For me, as soon as it's ALL liquid, it's ready. Like I said, lost foam or super thin castings might need a little more heat, say 1 minute.  :dremel:

Tom, I know the feeling exactly -- there was a delay of 2 years in this thread, when all my machining stuff was buried under other house project tools, materials, etc. Feels good to be back at it, after taking care of other necessary tasks.  :beer:

Thanks for the advice, i will try next time casting, but first i have to fix the car steering, the belt grinder and, and and
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 11:44:05 AM
Opening out the pulley bore to suit the spindle:

(http://www.vtsteam.com/Lathe/DrivenPulley9.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 11:45:08 AM
And finally, trial fitting the spindle, bearings and new pulley to the headstock:

(http://www.vtsteam.com/Lathe/DrivenPulley10.jpg)
Title: Re: Building a New Lathe
Post by: Neubert1975 on June 26, 2018, 12:44:24 PM
very nice, cant be long before the first cuts  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 03:52:27 PM
Thanks Neubert. :beer:

What's going to take some time is probably sending for the right size toothed belt. Definitely not a local pickup item here. So I'm concentrating now on sizing that, which means mounting the motor.

I cut the legs of the bracket much shorter than they had been for the temporary boring bar setup at the tailstock end. Then drilled new pivot holes. Here's the motor bracket clamped for marking with a transfer punch.

(http://www.vtsteam.com/Lathe/MotorBracket1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 04:00:26 PM
After removing the tailstock, carriage assembly and headstock, I was able to flip the bed on its side and use a hand drill to put two mounting holes in the bed. These parts are getting heavy!

Then the start of tapping. Always a little edgy putting threads full depth in 3/4" hot rolled steel. I go slow and use lots of sulphured tapping oil. Takes awhile but I do get through.

(http://www.vtsteam.com/Lathe/MotorBracket2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 04:02:44 PM
And no broken taps, The bracket is mounted -- previously the existing treadmill motor bracket was spot brazed to a bit of pipe nipple. The whole is shot through with a 5/16" bolt. I'll add packing washers later....once I know where the pulley needs to sit.


(http://www.vtsteam.com/Lathe/MotorBracket3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 04:07:37 PM
The bed turned right, and other parts re-mounted to check clearances and alignments. The motor is now hinged, but resting on the bench, without a belt (or its toothed pulley -- yet to be made). I have some space for it to rise, but it can't come too far up or it will interfere with the boring table in its extreme left and back position. But there is definite room. The belt will just have to be sized right. And for that, I'll need to make its pulley.

Also I need to mill out the top of the bed's back piece so the headstock can be moved full aft before permanently mounting it.


(http://www.vtsteam.com/Lathe/MotorBracket4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 08:49:57 PM
Just to get a belt ordered, I kept going after dinner on this one. Rather than casting a new blank I rumaged around and went with ...

The lowly sprue:

(http://www.vtsteam.com/Lathe/DriverPulley2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 08:55:46 PM
Turning down to 1.126" for a 18T XL driver:

(http://www.vtsteam.com/Lathe/DriverPulley3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 09:02:33 PM
I turned the ends down to .875", bored .667", and since the old setup was still in place on the mill, all I had to adjust was the depth of cut, after tightening in the collet. The tooth cutting was much easier, only 18 teeth, and no need for the vernier -- just rotate to every even hole.

(http://www.vtsteam.com/Lathe/DriverPulley4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 26, 2018, 09:15:19 PM
While not completely finished (it needs cheeks and a set screw) I slipped it on the motor shaft and got a measurement for the belt - 28.4". The closest available matches were  280XL063 and 290XL063 so I ordered both. Delivery by July 2. Won't be turning anything before then, for sure.

No longer a lowly sprue.

(http://www.sredmond.com/vtsteam/Lathe/DriverPulley9.jpg)
Title: Re: Building a New Lathe
Post by: Homebrewer on June 26, 2018, 11:44:41 PM
Looking pretty fantastic so far!

Are you still planning to drive the leadscrew electronically or with a series of belts as well?

Sent from my SM-G950U using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on June 27, 2018, 08:02:04 PM
Thanks Homebrewer. :beer:  Not sure about the electronic leadscrew, yet.

The driver pulley and some 5/8" washers:

(http://sredmond.com/vtsteam/Lathe/DriverPulley10.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 27, 2018, 08:02:46 PM
Opening washers for drive fit.

(http://sredmond.com/vtsteam/Lathe/DriverPulley11.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 27, 2018, 08:03:14 PM
Finished pulley:

(http://www.sredmond.com/vtsteam/Lathe/DriverPulley12.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on June 28, 2018, 02:06:11 AM
How does it fix to the shaft Steve?

It's a bit thin for a key or a grubscrew
Title: Re: Building a New Lathe
Post by: vtsteam on June 28, 2018, 09:55:14 AM
Two set screws @ 90 deg through the spline area. There's plenty of metal. Go back three photos and add the spline area depth to the extensions. That's more depth than the set screw is long, which is all you can get out of any of them.

Flats milled onto the motor shaft. I always mill flats with set screws.
Title: Re: Building a New Lathe
Post by: vtsteam on June 28, 2018, 12:18:51 PM
(http://www.sredmond.com/vtsteam/Lathe/DriverPulley13.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 30, 2018, 04:50:39 PM
I was hunting around to find a board to make a pattern for a faceplate. I figured maybe 8" diameter would be right. But I couldn't find anything suitable around the house, so I checked my bigger shop/household storage shed, and spied the faceplate I'd once bought for the Craftsman lathe. It looked about 8". Turned out to be 8-1/2".

Now this faceplate had been one of my worst Ebay purchases. In fact I had never used it once. I like faceplate work, but this particular one had been a great disappointment. It had a huge honkin' hub on the back of it, and very short slots. If you tried to bolt most anything useful to it, the hub was in the way. Not only that, but even if you could get the bolt in the slot, and the piece to be turned, the bolt head would often hit the hub. There was probably only one inch of useful range for those slots.

I had LOTS of faceplate accessories, built for my Gingery lathe, and 3 faceplates I'd cast for it. None of the accessories would work with this new faceplate. So it sat for 10 years, unused.

I started looking at it and thinking, could I use this with the new lathe, and maybe cut off that hub entirely?

(http://sredmond.com/vtsteam/Lathe/FacePlate1.jpg)


Title: Re: Building a New Lathe
Post by: vtsteam on June 30, 2018, 04:53:53 PM
Yeah Baby!

(http://sredmond.com/vtsteam/Lathe/FacePlate2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 30, 2018, 04:55:19 PM
Boring through to fit the front register of the spindle.


(http://sredmond.com/vtsteam/Lathe/FacePlate3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 30, 2018, 04:56:23 PM
Then a clearance bore to fit the mounting flange.

(http://sredmond.com/vtsteam/Lathe/FacePlate4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 30, 2018, 05:02:16 PM
And a test fit on the new lathe spindle. Really nice fit. And the spindle flange is recessed into the faceplate instead of interfering with slot bolts, as the earlier hub had.

I also plan to lengthen those slots toward the flange. They could actually go right to the back flange (not the register you see in front) because there's still massive amounts of steel forward of the flange. It's a steel faceplate, not cast iron. That will give additional range for the slots. Enough to make this a useful faceplate after all.  :med:

(http://sredmond.com/vtsteam/Lathe/FacePlate5.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on June 30, 2018, 10:52:16 PM
I got an email note that the belts had been delivered this evening, so I took a walk out to the mailbox, and there they were, two days ahead of time. So, belt on:


(http://sredmond.com/vtsteam/Lathe/BeltOn.jpg)
Title: Re: Building a New Lathe
Post by: PekkaNF on July 01, 2018, 05:06:04 PM
Starts to look like a proper Lathe!
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 01, 2018, 05:08:08 PM
Starts to look like a proper Lathe!

agree  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on July 01, 2018, 07:40:11 PM
Thanks, boys!  :beer:

I'd like to see it make chips. But there's a lot of loose ends to get to before I can. For instance, the headstock is just sitting there.... not fastened down. Bearing grease and final alignment. Bearing swarf covers. tailstock ram, lock, and handle. Back plate for chuck. Motor tensioner. Tool mount. Compound slide. Dead centers. :whip: 

Well some of those aren't strictly necessary to cut something, but in general, still a lot to do.

And today our thermometer hit 99 F. I had to mow lawns with tractor -- I'd let all that slip for a couple weeks while concentrating on this lathe. Basically it was haying, not mowing. We have 3 more days of this heat. Quite unusual for Vermont.

Oh also, I'm going to start to build a bridge this summer. That might slow things down. But I don't want to just stop, as I did the last few years, while building the "waterball" cistern. I'll try to get something done every day or so on the lathe.

Title: Re: Building a New Lathe
Post by: vtsteam on July 02, 2018, 05:20:57 PM
Excavator arrived today, and a lot of the block for the new bridge abutments. And another day in the upper nineties heat wave. But that didn't stop us from deciding to make it a casting day, too!

In the morning cool, I started on the pattern. I used cherry this time, as it takes nice detail, and has tight grain. I had to turn it and I didn't want any rough tear-outs. First I jigsawed out the rough blank, then sanded to the circle outline with my little disk sander set to a few degrees off square to add some draft to the pattern. Then I used a hole saw to open out the center. After that, I bored the center out a little more using the compound to again add a little draft.

Finally I coated the pattern with a sanding sealer, which I make by adding baby talcum powder to lacquer (the old fashioned talc kind, not the modern corn starch kind). This is the piece at that stage:

(http://sredmond.com/vtsteam/Lathe/Covers1.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on July 02, 2018, 05:22:57 PM
Steve,

If the bridge looks anything like as nice as the lathe it'll be pretty d... good  :thumbup:

Pictures needed of course  :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on July 02, 2018, 05:32:31 PM
Thanks Andrew! :beer:  I don't know how nice it will be, since it's a pretty utilitarian design by an engineer for a logging company that used to own this property. We're re-using those 20+ year old plans -- the approvals to do this have taken 6 months to straighten out, but we have the green light finally for excavating tomorrow. By re-using the plans, the approvals and permits were easier to get. It will be an amazing luxury to be able to drive to our house, rather than carry fuel and groceries by hand 600 feet up and down hill in winter (or heat wave as the case may be). Okay, I'll put some photos in the Watercooler section as it happens.  :med:

Uhhhh where was I, oh yes the pattern......sanding the sealer makes nice baby powder dust and is super easy. The sealer dries in ten minutes also.

(http://sredmond.com/vtsteam/Lathe/Covers2.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on July 02, 2018, 05:34:18 PM
Then I just hit it with rattlecan Krylon, which is also lacquer based.

(http://sredmond.com/vtsteam/Lathe/Covers3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 02, 2018, 05:34:58 PM
Let it dry for about 15 minutes, and we have a pattern.

(http://sredmond.com/vtsteam/Lathe/Covers4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 02, 2018, 05:38:10 PM
It was so hot today, I don't think I used much fuel, even for brass! Just kidding. But as long as I was hot and sweaty, what's a little more heat?  :whip:

(http://sredmond.com/vtsteam/Lathe/Covers5.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 02, 2018, 05:40:41 PM
Shake out time.

And a duck indoors for a cold iced tea after! No air conditioning, just a fan, but it still felt good.

(http://sredmond.com/vtsteam/Lathe/Covers6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 03, 2018, 05:10:35 PM
Sprue and flash cleaned off:

(http://www.sredmond.com/vtsteam/Lathe/Covers7.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 03, 2018, 06:34:57 PM
After cleaning up on the lathe:

(http://www.sredmond.com/vtsteam/Lathe/Covers8.jpg)
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 03, 2018, 06:38:20 PM
and as usual it look good  :beer: :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on July 03, 2018, 06:43:40 PM
Hoping to get at least one good bearing cover out of it, Neubert, and if lucky, two. And as usual thank you kindly, bud!  :beer:
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 03, 2018, 07:04:01 PM
then two it is  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2018, 07:42:11 PM
Here we go Neubert, cutting a recess:

(http://www.sredmond.com/vtsteam/Lathe/Covers9.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2018, 07:43:10 PM
I flipped the piece and cut another recess from the other side:

(http://www.sredmond.com/vtsteam/Lathe/Covers10.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2018, 07:44:23 PM
Time for lunch and a cooling tea. Temps still in the 90's:

(http://www.sredmond.com/vtsteam/Lathe/Covers11.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2018, 07:45:24 PM
Then I split the two covers off, and faced and finished them:


(http://www.sredmond.com/vtsteam/Lathe/Covers12.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 04, 2018, 07:47:18 PM
And here they are. Found a little casting flaw in one of the covers, but we'll call it good enough for who it's for.

(http://www.sredmond.com/vtsteam/Lathe/Covers13.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 05, 2018, 01:11:56 PM
Cutting wipers out of 1/4" hard felt:

(http://www.sredmond.com/vtsteam/Lathe/Covers14.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 05, 2018, 01:12:36 PM
(http://www.sredmond.com/vtsteam/Lathe/Covers15.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 05, 2018, 01:13:03 PM
(http://www.sredmond.com/vtsteam/Lathe/Covers16.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 05, 2018, 01:13:26 PM
(http://www.sredmond.com/vtsteam/Lathe/Covers17.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 05, 2018, 04:05:10 PM
Sawing the front bearing cover in half so it can be installed without pressing the bearings back off of the spindle.

The rear cover doesn't present that problem.

(http://www.sredmond.com/vtsteam/Lathe/Covers18.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 05, 2018, 04:06:18 PM
Felt wipers to fit:

(http://www.sredmond.com/vtsteam/Lathe/Covers19.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 07, 2018, 04:44:49 PM
Punching screw holes in the felt. First time I've used this leather punch tool -- I bought it in a bargain bin a couple years ago, for $3.99. Well, good investment -- It worked perfectly for the wipers.

(http://www.sredmond.com/vtsteam/Lathe/Covers20.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 08, 2018, 02:55:17 PM
In order to fit the rear bearing seal, I realized that I needed to make a spindle spacer -- it goes between the rear pulley and the rear bearing.  I took its O.D. from the front spindle boss, since my front and rear bearing covers are the same size. That's a little under 2 inces across. The I.D. needed to fit the rear of the spindle -- that's a little over an inch in diameter. The length of the spacer needed to be about an inch long.

So I began looking for 2" diameter scrap aluminum, at least 1 inch long. And I came up with this big sprue. Looking at it more carefully, I saw stamped on it "Al- Cu 4." Now why did I stamp a sprue? Oh yes, it's an aluminum copper alloy I experimented with in an earlier thread  https://madmodder.net/index.php/topic,10705.50.html     -- and made the lathe's bed end bracket with in this thread.

Since it's been a couple years I wondered if it's properties had improved through aging. The non-artificial type!

Anyway it was just the right size, so I requisitioned it.  :dremel:

(http://www.sredmond.com/vtsteam/Lathe/Spacer1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 08, 2018, 03:00:46 PM
It seemed to machine about the same as my typical cast aluminum. Maybe a little finer finish, but with the same ready tendency to weld a chip to the lathe tool and mess that up. It felt "crunchy", as noted before, not chewey, in case that means anything to anybody!

(http://www.sredmond.com/vtsteam/Lathe/Spacer2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 08, 2018, 03:05:06 PM
And here is the finished spacer, along with a piece of the sprue. To me, in very bright sunlight, I thought I could detect a very subtle copper tone to it, but maybe that was just my imagination.

I still don't know if it's any stronger than my conventional cast aluminum ( I use pistons, mostly). But the specs say so, so I'll accept that.


(http://www.sredmond.com/vtsteam/Lathe/Spacer3.jpg).
Title: Re: Building a New Lathe
Post by: PK on July 08, 2018, 06:22:57 PM
Nice job on the wipers. Brings back memories of a set I made a while back.   
Lets just leave it at "NEVER cut felt with a laser!"
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 08:03:14 AM
Thanks PK,  :beer: I laughed when I read about the laser! I can just imagine the felt was gone in a bit of smoke. Probably didn't smell too good.

I wasn't sure that making felt wipers for the spindle was a good idea or not. I don't think the 7x12 Asian mini-lathes have them. I think they use same size plastic bearing covers without packing. I was wondering if they use O-rings instead. But a tear-down video I watched didn't show them. The spindle in this lathe is designed for a mini-lathe and purchased on sale.

The covers and felts are almost all fitted as I write this. I was a bit worried that they were too tight, because there was definite drag on the spindle with the front felt in place. But I put a few drops of oil on the felt, and there was a big reduction -- enough to feel that friction will probably disappear altogether with a little break-in time once the lathe is working. Otherwise It's pretty tricky to try to trim back a small amount of felt, once they are cut out. Well, maybe if a laser worked! (and you had one).

Thanks again PK, that was funny!
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 02:12:14 PM
Finally finished putting the covers on!  :ddb:

That was a lot harder than I thought. Locating them on a round corner casting with draft, and drilling and tapping holes so they didn't interfere with the spindle or hit the spindle bore was really tricky and time consuming.

I probably could have made the clearance bore on the covers a bit wider than I did, but I used the same dimensions that the mini-lathes show for their plastic bearing covers. Since they don't use any seal or packing (to my knowledge) they show only about a mm clearance to the spindle, in order to keep swarf out.

With the hard felt seal, that opening could have been larger, which would have made locating the covers a little less of a hassle. Oh well, They're in now and I can move on.

(http://www.sredmond.com/vtsteam/Lathe/Covers22.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on July 09, 2018, 02:16:17 PM
Looks very smart and has a classical look to it  :thumbup:
Title: Re: Building a New Lathe
Post by: S. Heslop on July 09, 2018, 02:51:53 PM
Glad to see you're back at it. It's amazing how much the paint transformed it. It looks real swish!
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 04:13:45 PM
Andrew, thanks very kindly -- it means a lot coming from you!

I kinda like the way jewelers lathes look, and also I really love the Rolls Royce lathe (I'll find a link in a little bit), though I know I'm not at their level of workmanship. Still, I wanted to make this a personal lathe, and I like old machines, so it's kind of coming out that way. I didn't draw plans for anything except the headstock -- it's just evolved along with this thread.

Kind of ironic that I started it 3 years ago asking folks here what lathe I should buy, because I wanted to build engines right away, and the Gingery wasn't up to the job, and my Craftsman too big to fit on the bench of my tiny shop. I said I didn't want to build a lathe, because that would just delay building engines. Somehow that concept slipped..... Uhhhhhh, yes Steve it would!

When this thing is done, I am building engines  :wack:
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 04:17:27 PM
Simon, Simon, so great to hear from you again! It's been so quiet with most of the old hands off somewhere else, I guess. Well life intervenes...

What are you doing these days? What are ye up to? Do you still cruise the electric bike? Does the helmet still fit? Sanded anything with your purple machine, making files, gee I miss all that stuff!
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 04:41:24 PM
This is my favorite lathe -- the Rolls Royce of lathes, naturally.

While mine is quite different in construction, size, and probably well let's admit it, quality, there's something about it's classic style that influences what I do with this lathe. Within the bounds of my skills and what I have to work with.

http://www.lathes.co.uk/rolls-royce/img6.jpg
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 09, 2018, 06:46:59 PM
no wonder why its your favorite lathe, what a beauty it is.
And so is yours, nice work (as always ;-) )  :beer:
Title: Re: Building a New Lathe
Post by: S. Heslop on July 09, 2018, 06:53:45 PM
Simon, Simon, so great to hear from you again! It's been so quiet with most of the old hands off somewhere else, I guess. Well life intervenes...

What are you doing these days? What are ye up to? Do you still cruise the electric bike? Does the helmet still fit? Sanded anything with your purple machine, making files, gee I miss all that stuff!

Thanks for the concern. I've kinda lost the plot the last couple years. Been doing stuff that's too mad for Madmodder. See this, for example. (https://youtu.be/j1IhSBcsK98) And try not to get a fright!

And boy was that video a flop. I think I posted it at the worst possible time since youtube had just changed its algorithms to bury anything that isnt a top 10 lifehacks finger family kids react cringe compilation video, plus it's a weird niche topic.

At some point i'm going to get into the 3d printer game - I've had a couple false starts and i'm distracted with another project.

I think 3d printers are silly and overhyped, but for the urethane masks featured in that video it'd probably be the ideal tool to eliminate the messy expensive moulds and toxic chemicals. I'd like to make a thread for that when I get around to it. Really I should've made a thread about that mask since alot of the stuff involved is fairly interesting. At least I think it is. But it's taken me this long to get over the embarrassment.
Title: Re: Building a New Lathe
Post by: S. Heslop on July 09, 2018, 07:15:40 PM
This is my favorite lathe -- the Rolls Royce of lathes, naturally.

While mine is quite different in construction, size, and probably well let's admit it, quality, there's something about it's classic style that influences what I do with this lathe. Within the bounds of my skills and what I have to work with.

http://www.lathes.co.uk/rolls-royce/img6.jpg

That is a nice lathe! I've got a bookmarks folder of various tiny lathes i'd say I look at once every couple weeks, and that's one of them.

My personal favorite are the Pultra lathes. I keep forgetting they're English made. Something about them feels French to me. The French are good at being just that little bit weird, but in a very appealing way.

http://www.lathes.co.uk/pultra1750photoessay/

http://www.lathes.co.uk/pultra/img52.gif
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 07:49:13 PM

I've kinda lost the plot the last couple years. Been doing stuff that's too mad for Madmodder. See this, for example. (https://youtu.be/j1IhSBcsK98) And try not to get a fright!
...... I'd like to make a thread for that when I get around to it. Really I should've made a thread about that mask since alot of the stuff involved is fairly interesting. At least I think it is. But it's taken me this long to get over the embarrassment.

Simon that was FANTASTIC! I don't know what you're talking about... "embarassment"  :wack:

What a tour of creative methods and problem solving, and I love the nuttiness of it, gets well past the boring YT videos for me of ten minutes of explanation of what someone is about to do, then twenty seconds of doing it, and another 5 minutes of recap and a plea to click and subscribe.

In your case I actually have to slow down the video to catch everything I'm interested in, man you trim things to the bone! Wait, what'd he do just then??? Did he just iron a drainpipe? Does he always cut towards his fingers? Wow, cool, etc.

You ought to be proud of that.

ps.  my 12 yr old  daughter loves fenuc foxes, but apologies if I'm wrong in my guess here.

You HAVE to at least post a link to this video in the Composites and Plastics section of Madmodder. And an apology for not trusting that we're all at least as mad as you are.

Plus we'll probably double your hits for that vid.

Simon, you're desperately needed here!  :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 07:58:41 PM
Hey that Pultra is also one I love. Very stylish and simple lines. You know, there's engineering, and then there's design. And when good examples of both come together in one object, that's art.

The word art is one that has had its true meaning lost. It's not just paintings on walls, or sculptures. It's skill at empowering objects with something beyond the ordinary.
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 08:10:29 PM
no wonder why its your favorite lathe, what a beauty it is.
And so is yours, nice work (as always ;-) )  :beer:

Hey Neubert, sorry I missed your comment a few minutes ago. Thank you kindly as well, too, buddy! It's people like you that spur me on to get moving and posting! You make this fun..  :beer:
Title: Re: Building a New Lathe
Post by: WeldingRod on July 09, 2018, 08:17:15 PM
Frankly, I like the lines of yours much better than either of those examples!  Bring on the brass, and lovin' those acorn nuts!

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 09:12:35 PM
Thanks WR!  :beer:

Of course I didn't make the nuts.  :lol: But I bet Andrew could with that CNC lathe of his that turned the brass screws in a minute or so...  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 09:14:24 PM
Andrew....? Think you could do it?
Title: Re: Building a New Lathe
Post by: S. Heslop on July 09, 2018, 09:59:10 PM

I've kinda lost the plot the last couple years. Been doing stuff that's too mad for Madmodder. See this, for example. (https://youtu.be/j1IhSBcsK98) And try not to get a fright!
...... I'd like to make a thread for that when I get around to it. Really I should've made a thread about that mask since alot of the stuff involved is fairly interesting. At least I think it is. But it's taken me this long to get over the embarrassment.

Simon that was FANTASTIC! I don't know what you're talking about... "embarassment"  :wack:

What a tour of creative methods and problem solving, and I love the nuttiness of it, gets well past the boring YT videos for me of ten minutes of explanation of what someone is about to do, then twenty seconds of doing it, and another 5 minutes of recap and a plea to click and subscribe.

In your case I actually have to slow down the video to catch everything I'm interested in, man you trim things to the bone! Wait, what'd he do just then??? Did he just iron a drainpipe? Does he always cut towards his fingers? Wow, cool, etc.

You ought to be proud of that.

ps.  my 12 yr old  daughter loves fenuc foxes, but apologies if I'm wrong in my guess here.

You HAVE to at least post a link to this video in the Composites and Plastics section of Madmodder. And an apology for not trusting that we're all at least as mad as you are.

Plus we'll probably double your hits for that vid.

Simon, you're desperately needed here!  :beer:

You're exactly right with a fennec. And thanks for the encouragement, I guess I shoud post it in the plastics subforum. Really I just wanted to avoid having to answer the 'whats the deal?!' question since i'm not even sure myself. I got a text document somewhere full of failed attempts to write a summary, and the best thing I came up with is 'it's like the blues, where everyones got their own idea what its about and you sound like an ass if you try act as an authority on it'
Title: Re: Building a New Lathe
Post by: vtsteam on July 09, 2018, 10:06:52 PM
An expression from the late sixties, here:

just tell it like it is.

 :med:
Title: Re: Building a New Lathe
Post by: S. Heslop on July 09, 2018, 11:56:24 PM
An expression from the late sixties, here:

just tell it like it is.

 :med:

Hah. Well for myself I was calling it 'the last bastion of sincerity' but i'm not sure if that applies any more - it's changing rapidly. With the megasites like various social media platforms, youtube, and reddit the internets been getting way more cynical and any sense of community or shared involvement has been pulverized. But the furry community resisted that change for a while because it was just too dang weird. But it's still a sizeable demographic of consumers and more and more people are starting to realise and try take advantage of that and driving the genuinely weird and interesting stuff underground. Plus in this day in age alot of people my age, and maybe myself included, are starved for a sense of purpose and identity. Hence the rise of Identity Politics. And the whole community looks like exactly that - a community, and a neat identity to wear and show off on your lapel. There's perhaps nothing wrong with that, but it's also making it alot easier for carpetbaggers to exploit. A recent news story that's been making rounds is that there's now Chinese factories cranking out fursuits to try cash in on it, which is something I was jokingly predicting a few years back.

That still skips over explaining what it actually is. But whatever it was, i'm not sure if that exists any more.
Title: Re: Building a New Lathe
Post by: awemawson on July 10, 2018, 01:36:51 AM
Andrew....? Think you could do it?

Yes definitely if I could get at the Mirac lathe. It's all a bit tight in the workshop for some reason !
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 10, 2018, 05:57:13 AM
no wonder why its your favorite lathe, what a beauty it is.
And so is yours, nice work (as always ;-) )  :beer:

Hey Neubert, sorry I missed your comment a few minutes ago. Thank you kindly as well, too, buddy! It's people like you that spur me on to get moving and posting! You make this fun..  :beer:
No need to be sorry, i´am glad it helps making it worth moving on, and posting, i really enjoy following your amacing dog ladder project  :D
 :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on July 10, 2018, 08:55:58 AM
Heh, Simon, I just meant write here about what you do by way of making things, and don't worry about the consequences or perceptions. The interesting part for all of us is that people make things, and particularly out of the ordinary things, with their own zeal for it. Who cares what the reasons are!

And identity is nothing that can be taken away. Creativity is the evidence of an identity. No need for explanation or apology for making something unusual. This mad modder forum is exactly for that kind of expression.  We don't have a high tolerance level for web cruising critics here.  :whip:
Title: Re: Building a New Lathe
Post by: vtsteam on July 10, 2018, 09:04:37 AM
I know you're busy Andrew, but if you ever did get around to making one 5/16-18, I'll twist off a store-bought one from my lathe and put on an honorary genuine Mawson nut!

No jokes, please, I already get it!

Actually that would be a cool idea for a Mod-up -- anybody out there who wants to tackle a 5/16-18 brass acorn nut CNC or hand-turned can do that, and it will find a place on the lathe. Just open a thread and post some photos of your project in the Mod-Up section of this forum.

Should be an interesting exercise in creativity and methods -- an acorn nut has a ball end, hex section and deep blind thread. Not so simple.

I'd be happy to have MM nuts on my lathe.

And no jokes about that!
Title: Re: Building a New Lathe
Post by: WeldingRod on July 10, 2018, 09:33:37 PM
I often refer to my urges as "I suffer from the need to make things"  not that I really feel like its suffering, or restrict myself much on what to make ;-)

Making is a zen thing for me; I'm almost dead to the world focused on today's thing.  The earmuffs don't help that one either.

My 3D printer ran out the Devo energy dome, and a yellow jumpsuit was sacrificed.  My daughter suggested a costume fan.  OMG was it nice in that plastic suit!  The fact that I looked Michelin-esque was a bit of a drawback...

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on July 10, 2018, 10:10:48 PM
The face does look realistic, I'll give you that!   :poke:
Title: Re: Building a New Lathe
Post by: vtsteam on July 10, 2018, 10:38:19 PM
Okay back to the lathe. Today I cut out the interfering top bit of the aluminum stepper enclosure, and moved the headstock back to it's furthest aft position. This lined the drive pulleys up properly. 

I fitted the rear bearing cover and felt. But I found it was all too tight and it restricted the aluminum spindle spacer from rotating, even though I had tightened up on the spindle nuts to pre-load the spacer against the bearings. The spindle just rotated inside of the spacer.

So I decided to forgo the felt on the rear bearing cover -- I think the cover fits closely enough without it. The spacer and the big adjacent drive pulley will also block swarf, and this is the rear of the headstock anyway. The Minilathes don't have any packing here, so I'm going to call it good without felt. The front bearing cover felt is fine.

Then I made up a flat 3/8" by 1-1/2" flat  steel bar to fit across the top of ways inside of the headstock. This is the clamp that will will hold it stationary, along with a flat plate of 1/4" steel that is already there beneath the ways. That one runs the full length and width of the headstock, and served as a slide, while boring for the spindle. The .008" shims used when it was a slide have been removed, so tightening its 4 attachment screws will also clamp the headstock. But in addition I drilled and tapped the new clamp bar 3/8-16 right in the center, and drilled a 3/8" clearance hole in the bottom plate.

To finish clamping the headstock permanently I only needed a 3/8" by 1" bolt. Searching everywhere I could think of I could find NO 3/8 bolts whatsoever. That always seems to happen. 20 minutes of wasted time rummaging through toolboxes, cans full of old fasteners, not to mention the normal bolt storage places. Finally I grabbed a 1" length of 3/8" all-thread, took a grinder to the end and to a 3/8" nut, smeared some flux on it and silver brazed them together to make a bolt. Nothing's stopping me!  :zap:

The result-- the headstock is now permanently fixed to the lathe. Covers are done. Spindle turns. Pulleys line up. I think it's probably time to open up the cap one more time and grease the roller bearings -- a task I was avoiding 'til the very end of headstock work.

I dunno -- First I might just split the rear bearing cover like the front one. Otherwise it's a lot more involved removing the cap. If I split it, all I have to do to open up the headstock and inspect or remove the spindle/ bearing, and pulley assembly is loosen the 4 acorn nuts. I like that.

Anyway, this lathe is nearing being dangerous to metal.......  :borg:

 

Title: Re: Building a New Lathe
Post by: Neubert1975 on July 11, 2018, 12:18:23 PM
sounds like we allmoast can smell the metal chips from your lathe  :beer: :ddb:
Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 11:56:30 AM
Knock on wood Neubert! It was a bad day for me yesterday!  :bang:  I should say dumb day.  :bang:  :bang:

I spent a lot of the day making up a plug gauge out of aluminum. Spoiled the first attempt a couple hours into it. And started on a second. This plug was intended to, on one face, mimic the spindle flange, register, and bolt hole pattern, and on the other face, mimic the receiving end of any chuck, faceplate, etc.

To find the proper hole locations I placed the receiving face on the spindle flange, and transfer punched the hole pattern onto my new plug gauge. Then step drilled it to match.

When finished, I planned to turn it around and place the plug into the recess side of the faceplate, transfer the hole locations, and then drill and tap bolt holes on the faceplate to exactly fit the spindle. That was the idea, anyway.

When after the second try, I had my plug, all step drilled, and even stamped to indicate the three hole pattern and the four hole pattern holes, I felt it was time well spent. It was getting to be evening, and I figured I could now easily complete the faceplate attachment and mount it on the lathe.  Uhhhh........no.  :wack:

Almost evening, and I'd left my glasses in the house. No problem I could  see the transfer punch marks on the faceplate well enough, couldn't I, and heck, the 1/16" starter drill I was using fit well into those punches (which I'd even filed the burrs of of). It will find its center in the divot even if I'm off.

I drilled the three hole pattern with the first drill, then followed with a 1/8" spotting drill, and ..... and ..... and.... wait a minute. One of those three enlarged holes now looks awfully close to the register bore. That's not the same as the others...........whaaaaaaaaaaaaaaaaaaaaaaaaaaaat?

No, man, you do need glasses. Freakin dummy!

Well, guess you're going to have to drill the 4 bolt pattern instead, and just re-use one of the good holes.

So I start on that, I've got my glasses after a trip to the house, I've punched more locations and I've got two of those holes done with the 1/16th" drill, working on the third and last when it starts making an odd clicking sound -- maybe I better do another peck, been drilling this one too long and it's jamming up, I bet -- I go to lift it and bit snaps off clean in the hole. Whaaaaaaaaaaaaaaaaaaaaaaaaaaaaaat?

Man why didn't you drip some cutting oil on that spot first???????!!! -- the can is sitting not 6 inches from the drill press. What a mokohead!!!!!

Okay, now what?  Shift the whole thing and start again? That really frosts me! I've made a mes of it.

Just stop what you're doing and call it quits for the day. Let it go before you wreck something else. Sleep on it and start again tomorrow.

The plug gauge:


(http://www.sredmond.com/vtsteam/Lathe/PlugGauge1.jpg)

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge2.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 12:16:58 PM
Okay, so now it's a bright new sunshiney day. And this morning I woke up thinking......is this possible: maybe plug the first hole with steel and re-spot it and try drilling it again for the three hole pattern?

I don't want to use heat (brazing, welding) to fill it with metal -- I don't want to warp that faceplate or register. But what if I plug it with a bit of 1/8" steel rod, and say some JB Weld epoxy?  That stuff has done wonders for other problems in the past.

So this morning I hunted up a piece of water hardening 1/8" drill rod -- fully annealed, it just barely scratched the faceplate, so my guess is they are about the same hardness. And some JB Kwik (somewhat faster cure then the standard JB weld.

I cleaned out the hole well with lacquer thinner, and the same for the drill rod, clamped it in the vice and sawed off a small peg. Then I carefully swabbed the hole with epoxy, lightly coated the peg, and drove it home. The top burr prevented it from dropping below the surface (which would have defeated the whole re-drill attempt).

Will this work? I don't know. But we'll try it anyway.

Peg and epoxy:

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge3.jpg)

Peg in place:

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge4.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 02:20:53 PM
The sun warmed the faceplate quite a bit -- nearly too hot to hold in an hour, so I figured the epoxy was well set -- the bit I had mixed up on the card was pretty hard.

I carefully ground down the peg's top burr with a Dremel tool, and then screwed the plug gauge in place in the faceplate register. I'd drilled and tapped just one of the through holes earlier to serve as a reference point while marking out the other holes.

Then I punched the offset location with the peg repair:

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge5.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 02:22:17 PM
The punch worked to move the hole center over from the peg location:

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 02:23:39 PM
I drilled 1/8" through with a spotting drill -- I didn't want to risk another broken 1/16" bit in this tough steel faceplate.

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge7.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 02:25:05 PM
The hole center checked out whan I replaced the plug gauge. The new hole is at about 10:00 position in this photo (marked "3").

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge8.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 02:28:14 PM
And finally, I drilled it out to a #7 drill -- the tapping size. This fully removed the peg I'd put in, and there is no evidence of my scew-up earlier.

Really happy that worked!  :ddb: :ddb: :ddb:

(http://www.sredmond.com/vtsteam/Lathe/PlugGauge9.jpg)


Title: Re: Building a New Lathe
Post by: S. Heslop on July 12, 2018, 02:39:48 PM
Nice save!
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 12, 2018, 03:06:39 PM
what a day i had, but at least i now know i´am not the only one that experiences those days.
as i always say when i have days like yours, tomorrow is  better ;-)

i dont know if its of any use, but i have learned that if i have to hit spot on in a hole or a punch mark, than i place the drille (in a drille press) over the hole. and by hand reverse the drill while lightley pressing with the drille press, then it will center.

 :beer:
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 12, 2018, 03:21:25 PM
Nice save, and nice work  :thumbup: :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 06:48:21 PM
Thanks Simon and Neubert.  :beer: Sure glad it worked! Happier today than yesterday, for sure.

I tapped the two remaining holes today, and man that steel is tough. Nearly an inch thick, too. I was beginning to wonder if I'd break the tap, for my next dufus performance. But I went slow -- sometimes only an eighth of a turn before backing. I got through it.

I was a little surprised to find out that the flywheel fit on only one way, with those three holes. The spindle flange itself is not perfectly drilled, apparently, and I copied that in my plug gauge. Oh well, at least it goes on one way. I stamped numbers at the holes in the flange and the face plate, so I could put them together more easily in the future.

I mounted everything, now bolted together, and it spins nicely in the bearings. So I tried one other thing that I think I  mentioned a way back in this thread. That is, mounting my new 5" three-jaw chuck directly to the faceplate. It's very simple to add. Three flange head hex bolts through the faceplate slots.

(http://www.sredmond.com/vtsteam/Lathe/ChuckandFaceplate1.jpg)


The chuck is easily adjustable to center with a DTI -- just make the bolts finger tight, then rotate the chuck by hand, and tap the high side lightly with a wooden mallet until centered. Then tighten the three bolts. It's very quick. You can tighten the bolts with a socket wrench -- the headstock clears the bolts on the side.

I think this is going to be my standard chuck mounting method. While I could have made the usual backplate adapter for the chuck, it would have to extend out from the headstock the same distance that it does on the face plate. The spindle flange is deeply inset into the face plate to reduce overhang. So it's the same as a backplate.

It would be a lot harder to change over with a backplate adapter than with the faceplate-- not much space for an allen wrench behind the spindle flange, and they're much harder to manipulate back there.

With the way I have it now, I can also easily remove the chuck (with work in it) to bring to the mill, and then replace it using the DTI-mallet method again.

I think this is going to work well for me.  :thumbup:

Title: Re: Building a New Lathe
Post by: vtsteam on July 12, 2018, 09:36:48 PM
I should add that I'll probably drill three holes in the faceplate rather than use the present slot mount so it's a closer fit on the bolts. And I might make a thin disk to fit the rear register of the chuck, and dowel pin that to the faceplate and include a retaining screw for it. That would be easily removable when using the faceplate alone. Then chuck replacement will be repeatable. But for now I'll probably just use it as is.

Getting very close to being able to turn with it. Next up is drilling and tapping the top of the cross slide to take tool holders, accessories, compound slide, T-bars, etc. I haven't yet decided on a hole pattern, but will probably do that tomorrow. This is getting exciting for me! :dremel:
Title: Re: Building a New Lathe
Post by: awemawson on July 13, 2018, 01:34:23 AM
Then all you need is a set of radially drilled holes on the edge of the face plate, and a suitable detente pin, and you have a nice simple.dividing set up
Title: Re: Building a New Lathe
Post by: vtsteam on July 13, 2018, 10:12:22 AM
Well, I was thinking about doing that with the spindle pulley, Andrew, as was done on the Craftsman. But certainly do-able either way...... or both.  Maybe even with a pin vernier, like the collet spinner has.

But that's future stuff. Gotta concentrate on the basics for now. No tool holder, and no operable tailstock ram yet.











Title: Re: Building a New Lathe
Post by: vtsteam on July 13, 2018, 01:08:15 PM
Ughhhh, I spent the morning looking at ten other lathe's cross slide patterns, tool posts, ways of doing things and my head is spinning trying to figure out just what holes to put in that cross slide, where, and what size and thread, etc.  :doh:

It's a lot easier to add stuff within the limitations of something you already have, than to just start drilling into a blank slate. I've got too many what ifs floating around in my mind. I gotta take a break. Have to get the truck inspected anyway. I'm outta here.
Title: Re: Building a New Lathe
Post by: ddmckee54 on July 13, 2018, 02:40:50 PM
Yup, not building something until you've got the BEST design often results in it not getting built - DAMHIK.

If all else fails, write your designs down on slips of paper, throw them in an hat, close your eyes and pick one.  As you said, you can always add stuff to make it better; and it's not like you have to look very far to find a foundry that can cast new parts for you if you need them.

Don
Title: Re: Building a New Lathe
Post by: vtsteam on July 13, 2018, 02:58:30 PM
Thanks Don! :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on July 13, 2018, 09:09:47 PM
I think it's going to be a grid of .25" tapped holes on 1-1/2" centers.  :zap:


I'll screw in six Tee sectioned bars over that 1-1/4" x 1/2" to make up just a plain set of 5 Tee slots oriented across the carriage. Then anything else can be fastened down onto that.

Since this is a 9" lathe, I have a little more leeway for center height than a typical 7" mini lathe.

In fact I do need to pad up a fair amount to get tools near enough to center height.
Title: Re: Building a New Lathe
Post by: vtsteam on July 14, 2018, 01:49:00 PM
Nope, changed mind again. Not 1-1/2" square grid, but 1-3/8" by 1-1/2" rectangular grid. That will let me use 1" wide Tee bars instead of 1-1/8" -- an odd size.

I'm busy tapping 18 holes, now. Undecided whether to mill mill out steel Tee bars, or cast them in zamak. Since it's the weekend and I don't have the steel, and I'm an impatient cuss, probably the latter.
Title: Re: Building a New Lathe
Post by: awemawson on July 14, 2018, 02:49:08 PM
I suppose in the event of a calamity the Zamak could be a useful 'fuse-able link' and Tee bolts will pull though it rather than break something else.

Title: Re: Building a New Lathe
Post by: vtsteam on July 14, 2018, 07:35:39 PM
Well maybe not, Andrew -- it's stronger than cast iron, certainly in tension -- so not disadvantaged by most standard CI tee-slotted tables. Probably it would shear the 1/4" screws holding the tees down, as my own guess. They have a 3/4" bury in the table. Think a substance a little short of aluminum bronze, and you'll get a feel for it.

Of course I'm going to try to avoid inadvertent destructive testing!  :zap:  :beer:

I spent the day first tapping the holes, and then tuning up the cross slide. There were a lot of small details I'd left, and one forgotten step.

That last oversight was forgetting to run a hacksaw blade down the inside corner of the wear pads.  :palm:

Because I'd milled this slide, rather than filed and scraped it, as I had my earlier lathe, Gingery book in hand, I had forgotten to do this. Y'see, no endmill, no matter how sharp and new is going to maintain a perfect inside corner. With square ways, you have to cut out the tiny radius a mill will leave, so the pads are separated and contact the ways properly. The Gingery way is just run a hacksaw blade in the corner at 45 degrees until there's a small slot.

Anyway I realized my oversight when I took the slide apart, and found a 1 thou shim on that side only. Weird to shim one side, if the whole thing was done at one setting in the mill. Well the corner radius was responsible, and as soon as I made  the proper cut, the shim was no longer necessary. And of course the slide worked better, too!

Other tune-ups involved shortening the over-long gib screws, and fastening the cross slide leadscrew bearing in place with two flat-head screws. and squaring the slide to the ways.

The carriage now moves silky smooth, without wobble in any direction.
Title: Re: Building a New Lathe
Post by: S. Heslop on July 14, 2018, 07:44:47 PM
Are there any disadvantages with zamak? What I mean is, why isn't it used more.
Title: Re: Building a New Lathe
Post by: vtsteam on July 14, 2018, 09:13:13 PM
Simon, It's a real pain to machine, saw, file, or scrape. The only operation I've done with it that goes nicely, is tapping, for some reason. Boring holes is the worst. You need carbide for sand casting machining.

Now I know that hard machining qualities goes against the experience of other people, and maybe the alloy variety I've been making up is different than the variety they use. I dunno. But I believe my ZA-12 is correct. I'm using purchased virgin zinc ingots, and mixing in the right amount and type of aluminum (see the recipe, somewhere way back in this thread.)

I was using purchased ZA-2 earlier in the lathe construction (ie. years ago!) -- not mixing that myself -- and it seems to me that it was better/easier to work with than ZA-12. But I can't remember for sure.

The other negative thing is that it goes dull with age. I don't find that such a problem, as I intended to paint the lathe all along -- steel and iron rust, especially in the winter environment here, unless constantly used and oiled. Condensation does it. So it's just a different but similar problem.

And the ZA-12, at least, has huge shrinkage, when casting in sand. You really have to plan for that. It'll suck a hole right down the full length of a sprue. I'm thinking ZA-2 didn't do that as much. I'm going to have to try to do a comparison -- I think I have one ingot of ZA-2 left.

On the positive side, it is tremendously strong, solid, heavy, melts at the lowest temperature of the common structural metals, it's inexpensive, easy to cast (other then the shrinkage problem). I imagine it has excellent vibration damping qualities. It's very dense, but somehow, I dunno, "fluid" seeming

Oh also it's an excellent bearing material, unlike aluminum, or steel. So making lathe slides out of it is a really good choice, in my opinion. And the headstock feels massive and sturdy. My lathe is hard for me to even slide on the bench now, it's so heavy. The opposite of aluminum.

Well those are my experiences, anyway.
Title: Re: Building a New Lathe
Post by: S. Heslop on July 14, 2018, 10:42:38 PM
That's interesting to read. I've heard of it before in the context of bearings and also in a few older lathes switching over to zamak parts, implied as a cost cutting measure. So I was thinking of it in my head as the classic mystery pot metal and not really a useful structural material compared to aluminium. It's low melting point definitely makes it worth keeping note of.
Title: Re: Building a New Lathe
Post by: Fergus OMore on July 15, 2018, 04:11:46 AM
Simon

'Chinese metal' appears regularly in such things as vehicle carburetors and in model engineering, the feed nuts on Myfords are a zinc alloy.

One fault is that it does corrode until after a certain point it will be nothing more than white fluff! Chemically, it is somewhat worse than cheap brass.

However, it is easy to cast and I have rather a nice Unimat clone lathe made from -- lots of it.

Probably 'metal' for typesetting is something similar.

I hope that I haven't stolen the original post-- but Simon did ask

Norman
Title: Re: Building a New Lathe
Post by: seadog on July 15, 2018, 05:09:00 AM
That would be Mazak, Fergus.
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 15, 2018, 07:24:57 AM
 :beer: ;-)
Title: Re: Building a New Lathe
Post by: Fergus OMore on July 15, 2018, 07:59:58 AM
:beer: ;-)

I thought that I'd written about this - before my world was thrown topsy turvy.

Ah well, it's an absorbing post- thanks

Norm
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 08:18:06 AM
Simon

'Chinese metal' appears regularly in such things as vehicle carburetors and in model engineering, the feed nuts on Myfords are a zinc alloy.

One fault is that it does corrode until after a certain point it will be nothing more than white fluff! Chemically, it is somewhat worse than cheap brass.

However, it is easy to cast and I have rather a nice Unimat clone lathe made from -- lots of it.

Probably 'metal' for typesetting is something similar.

I hope that I haven't stolen the original post-- but Simon did ask

Norman

No problem adding to the conversation Fergus.

I would qualify the statement "it does corrode until after a certain point it will be nothing more than white fluff!" by saying that iron and steel will corrode until after a certain point they will be nothing more than red dust.

You are speaking of unprotected metal exposed to outdoor or saltwater environments, or road salt, which is true of both metals. Bronze and some aluminum, and corten steel alloys are the only answer for corrosion.

With regard to cheapening metal parts by use of die cast zinc alloys, the cheapening is mainly due to the ease of die casting these alloys allowing absolute minimum parts thicknesses and the very high strength of the material -- everything of that sort is hollow and usually 1/16" thick -- car door handles and such. It's a whole different ballgame in a 1/2" or 3/4" thick part, painted, except for wear surfaces and used in a lathe.

As an example, my own unpainted lathe, which has both steel and zamak parts, sat for a couple years in an unheated cinder block shop, with ice on the floor all winter.  When I returned to it this summer, the zinc parts had dulled to a nice evn gray, not white fluff, but a gray patina, looking very much like plain anodized aluminum. Quite servicable, as is.

On the other hand the carefully scraped and oiled steel ways had spots of surface rust which had to be removed. My drill press table was orange with surface rust, as was my iron vise, and just about everything else ferrous.

So, yes in certain applications -- chromed auto hardware, for instance, zinc alloys have been used to cheapen products, and corrosion may be a problem. But that doesn't have to be the way they are used. I think they have great advantages if used with a different approach, and I certainly wouldn't have gone to the trouble of putting them into my own lathe if they weren't ideal (from my perspective) for certain parts. After all I can cast Iron, brass, bronze, aluminum, and obtain and machine steel easily. And have, where I thought appropriate. I used zinc alloys by choice for purpose not cost reductions, and not for ease of machining (ugh!)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 08:51:25 AM
Of course, I do enjoy running against conventional wisdom. So far: welded steel lathe beds will warp, firebrick can't be used for melting iron, plaster of Paris won't make a suitable foundry furnace lining, and zinc alloys in a lathe will turn to powder.

Outside of this forum I've been told hundreds of times I can't do things I've managed to achieve, so I guess it's just a normal situation for me. I don't mind, just hope people widen their knowledge base. My firm belief is generalizations are true, except when it comes to specific cases. And even that belief has exceptions!  :lol:
Title: Re: Building a New Lathe
Post by: awemawson on July 15, 2018, 09:20:50 AM
You're like me Steve - you rise to the challenge. If someone says to me that something can't be mended it's like waving a red rag at a bull and I dig my heels in and charge!
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 15, 2018, 09:32:19 AM
sounds like a person i have been arround since birth  :)
When people tell me that things cant be done, i often answer, in that case i must be a magician.
and if i havent done it, it is like awemawson says, like waving a red rag at a bull  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 09:37:30 AM
btw, sorry just one more a humorous thought, I have a 20 year old garbage can (dustbin, Br.) that lives by the road, outdoors in all Vermont weather. It is hot dip galvanized steel (zinc coated). It's in fine shape -- no deterioration, despite its rough use, exposure to rain, corrosive contents, and proximity to road salt.

If it had been plain steel of the same thickness, treated this way for twenty years, it would indeed now be a small pile of rust flakes. My 20 year old house roof is also made of galvanized steel sheeting. In fact the very roof that protects my ferrous machine tools from the elements is also zinc coated.

I know some rake is going to point out the galvanic series now, and trot out old saws about anodic protection, but I would ask that he or she then consider all-zinc roofs. No steel couple. Why in the world choose a metal that will turn to white fluff to protect against the elements?

Tell me when my zinc headstock will be powder, so I can switch off the lathe in time, boys!  :lol:
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 15, 2018, 10:14:09 AM
btw, sorry just one more a humorous thought, I have a 20 year old garbage can (dustbin, Br.) that lives by the road, outdoors in all Vermont weather. It is hot dip galvanized steel (zinc coated). It's in fine shape -- no deterioration, despite its rough use, exposure to rain, corrosive contents, and proximity to road salt.

If it had been plain steel of the same thickness, treated this way for twenty years, it would indeed now be a small pile of rust flakes. My 20 year old house roof is also made of galvanized steel sheeting. In fact the very roof that protects my ferrous machine tools from the elements is also zinc coated.

I know some rake is going to point out the galvanic series now, and trot out old saws about anodic protection, but I would ask that he or she then consider all-zinc roofs. No steel couple. Why in the world choose a metal that will turn to white fluff to protect against the elements?

Tell me when my zinc headstock will be powder, so I can switch off the lathe in time, boys!  :lol:

Lets just say, that i wouldent save materials for that day, i dont think it will come for the first 20+ years  :beer:
/quote]
Title: Re: Building a New Lathe
Post by: Fergus OMore on July 15, 2018, 10:22:27 AM

Perhaps -a salt and battery? :scratch:

Somewhat whimsically

Norm
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 10:39:46 AM
Okay, off the jokes, here's some simple data re. casting.

Zamak 2 Ultimate tensile strength is 52,000 PSI (apologies to metric folks, but just for relative comparison)
Zamak 12 is 58,000 PSI
SAE1008 steel is 42,000-52,000 PSI
Named aluminum casting alloys ~ 45,000 PSI

For yield strength:

Zamak 2 = 41,000 PSI
Zamak 12 = 46,000 PSI
SAE1008 steel = 20,000-40,000 PSI
Named aluminum casting alloys ~ 22,000 PSI
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 11:16:06 AM
So what are the implications of the above? Well yes, cast parts can be cheapened by a manufacturer, because it is so strong, you can design a part to use very little material, by forcing it into webs and hollow shapes. They feel cheap, too because they are relatively light in weight. And they are brittle because the thin webs have ironically, the tremendous yield strength of the material.

Now suppose you don't want to cheapen a part. But are looking to endow a lathe (for example) with high strength and stiffness. So you build parts with equivalent thickness in ZA-12  to cast iron or steel. In this case the yield strength of the part will be enormous. Greater than any other metal you could cast.

The parts won't be brittle in any practical sense, because the application can never come close to generating yield  forces. The strength of the part will exceed most everything you could build out of except hardened tool steel. The mass will be substantial, because Zamak weighs almost as much as iron. It won't feel or seem cheap or insubstantial. When painted, one casting looks the same as another.Iron is also painted for resistance to rust.  Zamak does have the advantage of bearing slipperiness, so it will be better than steel for slides, and stronger there than cast iron, which is also a good bearing.

In other words, for me, it was the material of choice.
Title: Re: Building a New Lathe
Post by: WeldingRod on July 15, 2018, 11:20:50 AM
I think y'all are worrying about zinc pest:
https://en.m.wikipedia.org/wiki/Zinc_pest
Modern lead free alloys don't suffer from this.
Fascinating reading!

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 11:57:32 AM
Good point WR.

I don't melt anything with lead in it (for health and safety reasons), use a separate graphite-clay crucible for Zamak melting only, and use stamped pure known zinc and Zamak-2 ingots, from the same supplier.

The cast parts have shown no deterioration in extreme humidity changes in an unheated shop over 2 years. So-all-in-all I think my lathe is safe from the lead contamination problem (zinc pest).
Title: Re: Building a New Lathe
Post by: S. Heslop on July 15, 2018, 12:32:55 PM
Of course, I do enjoy running against conventional wisdom. So far: welded steel lathe beds will warp, firebrick can't be used for melting iron, plaster of Paris won't make a suitable foundry furnace lining, and zinc alloys in a lathe will turn to powder.

Outside of this forum I've been told hundreds of times I can't do things I've managed to achieve, so I guess it's just a normal situation for me. I don't mind, just hope people widen their knowledge base. My firm belief is generalizations are true, except when it comes to specific cases. And even that belief has exceptions!  :lol:

I think it's important to run against conventional wisdom at least a little bit, especially to make up for differing tooling. I can't see myself ever melting cast iron but I can manage aluminium and presumedly zamak too. The thought of which is rekindling a few project ideas i've had.

I think going against conventional wisdom it's also important for the sake of a community. On the internet especially I feel everything ranges from either a Community - or a Cult of Personality. And where a community innovates and shares ideas, a cult of personality copies ideas and waits for the great masters to bestow more wisdom upon them. Which you can really see in the hacker maker world, not to disparage them too much because there are cool people involved, but the vast majority have a hard time imagining anything outside of the capability of a 3d printer or laser cutter since they're surrounded by media personalities with sponsors and partnerships trying to sell them more.
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 06:20:23 PM
Well, I used to feel that way re. pop-tech more than I do now. I don't mind, as long as somebody doesn't tell me that's the only way to do things. In fact I owe apologies for negative sentiments I  expressed a few years ago re. 3D printers. Not that I want one, but why shouldn't other people be happy? I just figure, now, that people should do what they're interested in. Including cultivating personal fame if that''s what they want. Me, I like metal, and traditional basic things, and old ideas losing currency now. That's fun for me. I don't like plastic, so I'll probably never make stuff out of it unless there is no viable alternative for something I really want to do.

End of structural politics...... anybody want to get back to making this lathe? And messing with zinc? Okay, then.

Today, I took this organic substance called scrap wood and sawed it into a desirable, to me, shape. This is one of the earliest materials used by man, and it is possible to make it conform to your mental ideas of shape fairly easily with shaped tools and zero programming. It took at most 10 minutes to rip out enough stock for 16 of these patterns, though I didn't need that many -- I just wanted to have enough in case of goof-ups.

It had to have clearance around a Tee nut so it could slide, but enough overhang to hold without breaking, plus clearance to the top surface plus machining allowance. Ordinarily in pattern casting you'd also need draft and shrink allowances, but not in the way I intended to cast this today.

(http://www.sredmond.com/vtsteam/Lathe/TeeBars1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 09:18:36 PM
Raw stock again showing clearances and overlap:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars2.jpg)

After that I put my sanding sealer on, and waited 15 minutes to dry. Sanded and a second coat, sanded that and was ready to cast. I didn't go for a colored lacquer finish this time -- basically impatient. The castings would have come out cleaner, but I figured they'd be pretty good anyway without.

This is an example of the simplest kind of casting -- open top --  and it's ideal for long narrow uniform pieces, shaped like extrusions. We'll essentially "extrude" out the pattern, and replace it with metal. Maybe we should call this "lost wood" casting!  :loco:

Also because you don't need a conventional cope and drag and sprue, the space requirements are minimal. I have cast this way before in a tomato can. I needed a little more height this time so I used a kitchen canister.

(http://www.sredmond.com/vtsteam/Lathe/TeeBars4.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 09:28:42 PM
I ram this type of casting mould much harder than I would a conventional flask casting. I'm trying to keep detail crisp, and strengthen the greensand by compacting it hard . I'm not worried about permeability of the sand because the top is open.

I've pulled one of my "extrusion" shapes out of the sand. Too short to rap, I just grabbed it by fingertips, and wiggled gently as I pulled the pattern.

(http://www.sredmond.com/vtsteam/Lathe/TeeBars5.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 09:34:16 PM
Since there's no draft, only the wiggling allows the pattern to be removed. But because on a narrow part like this, there is little circumference, there is also reduced drag compared to something more massive.

Here I've finished  withdrawing patterns, and as an experiment I also made a pouring basin and runners (channels). I was thinking this might trap impurities and reduce the chance that I would collapse the part hollows by pouring directly into them. In the past with a single part, I just poured directly -- with good results. But this time I wanted to try something slightly more sophisticated.

(http://www.sredmond.com/vtsteam/Lathe/TeeBars6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 09:36:45 PM
I'd started the furnace when I started molding. It was ready when I was.

The pour w/ Zamak12. It starts out shiny as mercury. Total molding and melt time: 20 minutes.:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars7.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 09:38:24 PM
And in an other 20 minutes it looks like this. There is a typical hexagonal crystalization barely noticeable. Minor shrinkage (mainly due to the small volume of the parts.)

(http://www.sredmond.com/vtsteam/Lathe/TeeBars8.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 10:55:13 PM
This is the shakeout immediately after the last pic.

(http://www.sredmond.com/vtsteam/Lathe/TeeBars9.jpg)

I took file to the top and bottom, then took 3 thou off of both on the mill.  The upper piece has been rough filed, the lower skimmed on the mill. The tops will be final milled once attached to the cross slide so they end up flat and even.

(http://www.sredmond.com/vtsteam/Lathe/TeeBars11.jpg)

Here's the skimmed piece with the wooden pattern that made it. Notice how closely the dimensions match the original pattern. Wiggling the patterns in the mould increased the cavity size by a tiny amount, but shrinkage and filing flat compensated, so the pieces have near identical sections..

(http://www.sredmond.com/vtsteam/Lathe/TeeBars10.jpg)

Total time from concept, cutting rough stock for 16 patterns, sanding and finishing 4 of them, molding 2 of them, melting metal, casting, cooling and having in hand metal parts was 1 hour and 20 minutes.

I don't know of any pop-tech method that could compete for speed cost or simplicity or conservative use of materials and fuels than ordinary direct pattern making and casting.

I'm not trying to prove that one way is "better" than another, because this is all hobby stuff, and the interest and challenge are the most important products, not the objects we produce. But I do want people to understand the reasons for my personal choices -- many younger people do not actually understand them.

I do it this way because it gives me great joy to move that fast, that directly, and that easily from what I conceive, to what is there, ready to use. That personal choice comes from my own love of traditional skills and efficiencies. There is no intervening program, or computer or robotic tool. It's just me. That's my gas.

Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 11:08:24 PM
And the same section we started with in metal:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars12.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 11:21:15 PM
And since it was so easy to do the first two prototypes, and they turned out so well, why not do it again, only this time with four in a "spray"?

I'd started the last batch after 1:00. Plenty of time to do the rest before dinner time. So, hope this isn't too repetitious but


Skull and Crossbones?:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars13.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 11:22:04 PM
Patterns wiggled out:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars14.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 11:22:47 PM
Metal poured:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars15.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 15, 2018, 11:23:21 PM
More T-bars:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars16.jpg)
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 16, 2018, 09:29:15 AM
i like the way you made those castings, its one i will remember when i need some parts that would fit that way of doing it  :beer:
Title: Re: Building a New Lathe
Post by: S. Heslop on July 16, 2018, 10:03:09 AM
I don't know of any pop-tech method that could compete for speed cost or simplicity or conservative use of materials and fuels than ordinary direct pattern making and casting.

I'm not trying to prove that one way is "better" than another, because this is all hobby stuff, and the interest and challenge are the most important products, not the objects we produce. But I do want people to understand the reasons for my personal choices -- many younger people do not actually understand them.

I do it this way because it gives me great joy to move that fast, that directly, and that easily from what I conceive, to what is there, ready to use. That personal choice comes from my own love of traditional skills and efficiencies. There is no intervening program, or computer or robotic tool. It's just me. That's my gas.

There's alot of marketing in the 3d printer world. Guys like this (https://www.youtube.com/watch?v=MoDSK3NThCk) work tirelessly to steer discourse towards selling you stuff you dont need, and I think it's a conscious effort by some people to suppress smaller ideas and voices.

The local Maker society is currently in the process of fitting a rusted and faulty round column mill with stepper motors before fixing anything else with it, and they went for a laser cutter before even considering machine tools. I don't think it's stupidity or something on their part, it's just if you look up stuff online then you'll see mostly CNC, 3d printers, and lasers. There's alot of people who're just unaware of differing (and cheaper) methods, and if they do run into them they might disregard them. So I think it's important to put them in context and explain their value as you're doing.

Boy I talk about this stuff alot. Just imagine me pointing at one of those forensic string boards every time you read my posts. It's all connected!



Cool T bars by the way. And cool method of casting them! Can't wait to see them on the lathe.
Title: Re: Building a New Lathe
Post by: vtsteam on July 16, 2018, 09:24:33 PM
Thanks Neubert, Simon.  :beer: :beer:

Sorry to say there was no work on the lathe today. Worked on the bridge. Will have to do that tomorrow as well, unless it rains. Maybe I can get a little done in the evening.

Temps here were brutal again, but there's a night time thunderstorm right now, We need the water, so, no complaints..
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 17, 2018, 04:54:58 PM
no need to be sorry.
we have brutal heat here too, and today i have spend all day out in it, fixing my moms car, damn it was hot.
we sure could use some rain too, everything outsite is drying out.

 :beer:
Title: Re: Building a New Lathe
Post by: Homebrewer on July 17, 2018, 05:28:53 PM
I've got both you beat, fellows.  It's 106°F here in Texas with no rain or cool fronts in sight. 

It's times like this that I feel blessed to have an indoor job!

Sent from my SM-G950U using Tapatalk

Title: Re: Building a New Lathe
Post by: vtsteam on July 17, 2018, 07:48:12 PM
We got about 2 hours work on the bridge today before thunderstorms hit. They put down a couple inches of rain (badly needed) for the next 4 hours, and a flash flood hit the stream the bridge abutments are being built on. The water was over the coffer dams and about 3 feet up the new abutment. No damage or problems, but it sure did stop work.

I did get the the T-bars cleaned up some, shortened to length, and drilled them to take fastening to the cross slide. I was gratified to see all of the holes matched the slide's tapped holes perfectly -- not always an achievement for me. But they were all done on the mill, and my dial twiddling worked out.

Nothing much worth showing yet, They need to be countersunk, fastened, and then the whole surface milled together. But a little progress anyway.
Title: Re: Building a New Lathe
Post by: awemawson on July 18, 2018, 02:51:23 AM
 :worthless:
Title: Re: Building a New Lathe
Post by: PekkaNF on July 18, 2018, 03:21:41 AM
I have a big interes on this latest T-slot construction.

I haven been planiing/doodling a new top slide for my small lathe. Original is that shitty that it is next to useless. I use it only when i can't avoid it, other times it is replaced with a rires block on the cross slide - much better and more stable. It also has two holes for mounting this riser, places are defined to maximize working envelope, original fixing point wast not even compromise, it had bad sides from the tool overhang and diameter capacity.

Milling the T-slots is the industrial practice, but not always easiest to do in HMS. And tou need a bigger piece on stock to start with.

Fabricating the pieces gives you more versatility and you can replace the parts. Also looks easier to make on small mill.

You planning to align the T-slots accurately with the top-slide I.E. nearly perpenticular to spinde axis?

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on July 18, 2018, 10:41:51 AM
Sorry Andrew.

Pekka the holes in the cross slide and the T-bars were all done on the mill. Admission: unfortunately the first time I drilled the cross slide I hadn't checked the mill vise from the last time I'd used it, and it was slightly off perpendicular.  :palm: :wack:

But, since I decided that 1-3/8" spacing between rows was smarter than 1-1/2" (because I could use 1" wide bars instead of 1-1/8), I plugged the old holes, indicated the vise in accurately, and re-drilled everything with the altered spacing. Because of the change in spacing, none of the newer accurate holes impinged on the old holes. so it was all in new material. Then I tapped them. So to answer your question, the T-slots should all be accurately parallel with the bed ways.  :med:
Title: Re: Building a New Lathe
Post by: vtsteam on July 18, 2018, 10:46:52 AM
Pekka, you might recall I did a similar Tee-slot table before, though that time I just added the tops of the Tees:

https://madmodder.net/index.php/topic,8900.0.html
Title: Re: Building a New Lathe
Post by: PekkaNF on July 18, 2018, 12:09:33 PM
Pekka, you might recall I did a similar Tee-slot table before, though that time I just added the tops of the Tees:

https://madmodder.net/index.php/topic,8900.0.html

Thank you, I remember that one, but it was good to read again.

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on July 19, 2018, 06:08:21 PM
Yesterday was a full day 8-7 on the bridge. Today we poured some of the blocks in the morning, but that left the afternoon free. So I was able to countersink and mount the T-bars, and then mill the surface flat.

We have to do what we can, when we can!  :whip:

(http://www.sredmond.com/vtsteam/Lathe/TeeBars17.jpg)
Title: Re: Building a New Lathe
Post by: S. Heslop on July 19, 2018, 06:19:07 PM
Hell yeah, that looks awesome!
Title: Re: Building a New Lathe
Post by: RotarySMP on July 20, 2018, 05:56:50 AM
Nice work. On the whole lathe project. When I made the built up, steel, T-slot table for my little 7x12 chinese lathe, I also epoxied the parts together, in case the screws work loose.

http://wrathall.com/Interests/machining/T-slot_cross_slide6.htm

Mark
Title: Re: Building a New Lathe
Post by: vtsteam on July 20, 2018, 06:24:32 PM
Thanks Simon!  :beer:

Hi Mark, I thought about that earlier, but decided I wanted to be able to change things around easily. I did epoxy and screw the way pieces to the lathe bed back two years and twenty some-odd pages ago.

We fastened our tee-bars differently I noticed -- it looks like yours are fastened only at the ends, while mine are fastened all the way across. Both make sense depending on whether there is or isn't a glue assist. Looks like you have a nice site. Thanks for letting me see that. :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on July 28, 2018, 04:44:11 PM
I took a short length of hot rolled 4" x 1/2" steel bar, cleaned it up, and bored a 1" hole 1-1/8" from one side. Then I turned a 1" dia. shoulder onto a 1-1/4" round bar. and deeply chamfered the end.

(http://www.sredmond.com/vtsteam/Lathe/ToolPost1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 28, 2018, 04:49:07 PM
The rod was a tight slip fit into the plate. The shoulder was left a little short, and the chamfer turned because I wanted enough space for weld metal.

(http://www.sredmond.com/vtsteam/Lathe/ToolPost2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 28, 2018, 04:50:56 PM
The shoulder and tight fit assured that the parts would be aligned square when welding.

(http://www.sredmond.com/vtsteam/Lathe/ToolPost3.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 28, 2018, 04:57:18 PM
I welded the post to the base, then milled the bottom flat again. I also put a hole in the top of the post for tapping, to take other accessories, if needed.

Here, checking the location of the tool block, and drilling locations for final mounting to the lathe.

That's all for today. Between the thunderstorms and the concrete bridge form pours, it's fairly slow going, lately.

(http://www.sredmond.com/vtsteam/Lathe/ToolPost4.jpg)
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 28, 2018, 05:37:19 PM
looking good as always ;-)  :beer:
We finaly got some rain today too, and thunder.
we havent had a drop of water the last 3-4 weeks  and 30+ °c  :drool:
Title: Re: Building a New Lathe
Post by: krv3000 on July 28, 2018, 08:38:59 PM
as per a wondaful job  :thumbup:
Title: Re: Building a New Lathe
Post by: vtsteam on July 29, 2018, 07:21:09 PM
Thanks Neubert, Bob, always a pleasure to hear!  :beer: :beer: :beer:
Title: Re: Building a New Lathe
Post by: vtsteam on July 29, 2018, 07:22:57 PM
Another shake out:

(http://www.sredmond.com/vtsteam/Lathe/TopSlideBase1.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on July 29, 2018, 07:23:28 PM
Cleaned up:

(http://www.sredmond.com/vtsteam/Lathe/TopSlideBase2.jpg)

Title: First Swarf
Post by: vtsteam on July 30, 2018, 06:54:09 PM
And finally I used the lathe as a lathe (first time) to clean up the circular recess in the top slide base I cast yesterday.

I used the new fixed toolpost, which can either be mounted directly to the cross slide, or on top of the tee-bars. The hole spacing allows either.

The new top slide base will mount directly to the carriage.

(http://www.sredmond.com/vtsteam/Lathe/TopSlideBase3.jpg)

I was very impressed with the solid feel of the lathe. No chatter with this difficult zamac piece. I had decided I wanted to move the recess back 1/8" so I was facing the hole sides eccentric. There was sand in the rough cast surface. And I needed to relieve to a sharp inside corner. The carbide insert I had was not ideal for the above, HSS would have been better, but quickly blunted. The lathe cut through without hesitation.

I was also impressed by the power of the motor and belt drive, even at 100 rpm with a heavy chunk of casting off center and out of balance there was no slowing down in a flat side profiling cut. Even though it doesn't have back gears.

And the mass of the new lathe and the new roller bearings, meant that though the flywheel load was un-balanced, there was no vibration or jumping around. I normally add weights to balance anything as off center and heavy as this casting was, but when I first tried out low speed operation, the lack of vibration (plus to my impatience level) had me trying a cut, without problem, and then I just kept going.  :dremel:
Title: Re: Building a New Lathe
Post by: vtsteam on July 30, 2018, 06:58:24 PM
Relieving the center portion of the recess:

(http://www.sredmond.com/vtsteam/Lathe/TopSlideBase4.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 30, 2018, 07:03:50 PM
The base after turning.

 (http://www.sredmond.com/vtsteam/Lathe/TopSlideBase5.jpg)

There's a land near the outer edge that the top slide rides on, the inner part is relieved. Finish isn't perfect, as the insert wasn't ideal, and the slight regular groove pattern inside probably is a result of hand cranking -- I probably need to tighten cross slide gibs. But still, pretty good considering a first trial of a newly built lathe in a difficult material and shape.  :med:
Title: Re: Building a New Lathe
Post by: PK on July 30, 2018, 11:26:19 PM
That has to be a good feeling. Well done..
Title: Re: Building a New Lathe
Post by: RotarySMP on July 31, 2018, 02:26:52 AM
Hell of an achievement to manufacture a whole lathe. Good on you.
Mark
Title: Re: Building a New Lathe
Post by: Neubert1975 on July 31, 2018, 03:54:47 AM
Greate to see it in use.
well done, must feel good to try it out  :thumbup: :thumbup: :beer:
Title: Re: Building a New Lathe
Post by: awemawson on July 31, 2018, 04:32:09 AM
Cracking good job Steve  :bow:

At least you don't have to worry about chasing obsolete documentation and parts like the stuff I work on  :clap:
Title: Re: Building a New Lathe
Post by: vtsteam on July 31, 2018, 10:21:19 AM
Thank you guys kindly!  :beer: :beer: :beer: :beer:
Title: Re: Building a New Lathe
Post by: S. Heslop on July 31, 2018, 11:39:47 AM
Fantastic! I didn't even notice it was being turned on the homemade lathe till I read the text. I guess that might say something about how professional it looks!
Title: Re: Building a New Lathe
Post by: tom osselton on July 31, 2018, 01:06:31 PM
Glad to see it all come together well done!
Title: Re: Building a New Lathe
Post by: vtsteam on July 31, 2018, 11:20:24 PM
Thanks Steve, Tom,  :beer: :beer: I'm very happy to have built one instead of buying one as I'd originally set out to do in this thread. Though I never thought it would be a few years in the doing. I'm looking forward to the day when I can build engines with it.

Well, it's not finished quite yet, but the end is in sight.

Today I fitted the three jaw chuck to the faceplate. Three easily accessible hex bolts fit in the slots. Tighten lightly, put a clock on the work (a new tailstock ram), rotate by hand and tap the chuck with a wooden mallet to read half the difference between high and low readings, rotate again to check. In about 30 seconds it's turning within half a thou. Tighten the bolts and you're done.

I don't know how long it takes to adjust a Set-Tru or other proprietary chuck system, I do know how long it takes to center a 4 jaw chuck, even with the two key method. I think this simple system may be faster and easier.

I guess you could say I just have a larger diameter backplate than most lathes -- one that's more useful on it's own, too. And a register would just restrict my ability to clock it in to true center for any size work, and no matter what the scroll wear. I thought about making a thin chuck register plate to to fit on the faceplate, but have decided against it as actually less accurate, in the long run. Why lock the chuck into one permanent position?

I like the fact that I can use a regular crescent wrench and hex bolts above the headstock too, rather than trying to fit an Allen wrench in behind the spindle flange, as is done on the Asian mini-lathes. Much easier with a bigger backplate er...faceplate.

(http://www.sredmond.com/vtsteam/Lathe/ChuckClocking.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 31, 2018, 11:31:16 PM
I borrowed the tailstock ram and lock, guide, and wheel handle out of my Craftsman and temporarily installed them into the new lathe's tailstock casting. That allows me to use the new lathe to start making its own ram and tailstock hardware. I fitted a Jacobs chuck to the tailstock and began the first drilling operation, preparatory to boring a Morse taper in the end.

Drilling:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 31, 2018, 11:38:11 PM
I need a steady rest to do the taper boring, and I remembered I had bought an old one at the Bernardston Gas Engine show a number of years ago. I found it in a crate of other goodies after a short search and set it up onto the ways to compare its center to the headstock center. It was an inch tall, so it must have been for an 11" lathe.

(http://www.sredmond.com/vtsteam/Lathe/SteadyRest1.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 31, 2018, 11:46:47 PM
One leg was longer than other other, and one leg had a notch for prismatic ways. I marked it for cutting an inch off, and realized that would just leave the bottom web of the casting, for a nice wide flat surface.

It took a long while to figure out how to mount the casting on my 4x6 bandsaw, but some holes I'd tapoped came in handy for clamping it on top of the standard vise with some mill toe clamps and studs.

(http://www.sredmond.com/vtsteam/Lathe/SteadyRest2.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on July 31, 2018, 11:50:38 PM
Legs sawn off.


(http://www.sredmond.com/vtsteam/Lathe/SteadyRest3.jpg)


I then took it to the mill to surface the bottom.
Title: Re: Building a New Lathe
Post by: vtsteam on August 01, 2018, 12:04:51 AM
Unfortunately, when I re-assembled it, this steady rest turned out to be one of the worst examples of domestic casting I've ever seen. Not that the castings themselves were all that bad, but the fit and finish were horrendous. For one thing, the fingers were very roughly cast with the draft still present (not milled out), irregularly shaped on probably a belt sander (linisher?) and they were different thicknesses and didn't meet in a flat plane.

(http://www.sredmond.com/vtsteam/Lathe/SteadyRest4.jpg)

(http://www.sredmond.com/vtsteam/Lathe/SteadyRest5.jpg)




Title: Re: Building a New Lathe
Post by: vtsteam on August 01, 2018, 12:07:27 AM
Besides the different thicknesses of the fingers, the main casting channels had never been milled. They looked like someone had molded them with bubble gum. The irregularities added to the mismatch of the fingers, and keeping them in one plane was impossible.

(http://www.sredmond.com/vtsteam/Lathe/SteadyRest6.jpg)

(http://www.sredmond.com/vtsteam/Lathe/SteadyRest7.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on August 01, 2018, 12:17:40 AM
I considered milling the slots, but without a rotary table, that would have taken a long time to accomplish on such odd shaped castings. there were no planes to work from, and I'd have needed three odd setups.

Likewise the fingers, being wedge shaped in section, might not have fit well if milled square and flat. I could have made new ones, but this was turning into a major project. I did try to even out the slots with a die grinder, by hand, and I tried the fingers in different positions to get the best fit, and then stamped each one for easier replacement.

But at the end of the day, I decided to put the steady back in the odds and ends box as a total rehab project for another day (and a rotary table).

Instead I decided to use the steady I had made for my Gingery lathe. It needed only a 7/8" riser block. In a half hour before dinner I'd cast one in aluminum. Working fast,  I set the crucible full of old sprues in the tiny furnace, turned up the gas, cut a block of pine to the right size, and rammed it up without even applying a finish, and by the time the mould was ready, the metal was hot and ready to pour.

I forgot how nice aluminum is compared to Zamac. It comes out shiny like a new dime. It hardly shrinks at all, by comparison, and the casting comes out mostly sand free. I've thought about this -- Zamac is much more dense, and I believe sand may tend to float in it. Sand doesn't float in aluminum, I don't believe. Aluminum is also so much easier to cut with a hacksaw and file. A pleasure to work with, by comparison.

The shake out:

(http://www.sredmond.com/vtsteam/Lathe/SteadyRest8.jpg)
Title: Re: Building a New Lathe
Post by: WeldingRod on August 01, 2018, 11:32:31 AM
I made a follow rest a while ago using two layers of plasma cut plates.  I set things up so that I welded the layers together and then sawed off a section that was keeping all the slots right.  For that application I actually wanted the fingers in two different planes, so there were finger slots on both layers.  Worked really well!
I, um, might have made two of them because I didn't really understand what a follow rest really needed to look like...  the second one worked really well ;-)

Sent from my SAMSUNG-SM-G891A using Tapatalk

Title: Re: Building a New Lathe
Post by: krv3000 on August 01, 2018, 04:25:15 PM
coming a long well that support casting the panted on looks just as bad as these castings from Stuart wood be nice to see you make an engine on that lathe  :drool: 
Title: Re: Building a New Lathe
Post by: tom osselton on August 01, 2018, 04:27:11 PM
That is a horrid casting you would have thought they’d catch that at the factory.
I never have seen you recondition your sand is it linseed based?
Title: Re: Building a New Lathe
Post by: vtsteam on August 01, 2018, 09:22:10 PM
WR, that sounds interesting. I have a follower rest that I bought at the same time as the steady. But much better casting. Not sure what lathe it went to, but I will probably adapt it some time, if I can. But for now, I need a steady rest.  :beer:

Bob, I'm really excited to get going on engines as soon as I get the tailstock and top slide done. Shouldn't be too long now. You've done great stuff with those Stuart castings. Just goes to show you can always make something interesting and perfectly usable out of any kind of metal problem. All you really need is the desire and that can-do attitude. Metal will always yield to a person with determination!  :beer:

Tom, funny you should mention my greensand and reconditioning. I just use plain sand and fire clay (and water for non-ferrous casting. Nothing special. The fire clay I can get here (in Vermont) now is called "Hawthorn". Ceramics people use it.

But the funny part is, This is the same greensand I first mixed up in 2002 to build my Gingery lathe. It started out as about 100 lbs, and is now down to 50.

Yup, I've used the same greensand batch for 16 years, and for countless castings, including all of the present lathe, besides the Gingery and accessories.

However, I did think it was getting a little tired lately, so just before I cast the last aluminum riser block above, i added 5 quarts of new sand, and 2 quarts of fire clay. That brought it up in volume some, too. So your question is extremely timely!

I think you really meant, what do I use for liquid -- and that is plain water -- I use a spray bottle to evenly dampen the top surface of the sand, then trowel it under and repeat, until the sand feels right. Then I cast. I go entirely by feel of the sand.

I will say, that it still doesn't feel as good as it used to, and the castings don't look quite as good, so we'll see if this new addition really helps, or whether I should just discard it and start over. I do worry that new sand won't quite be the same as my old standby, and I actually feel a little nostalgic about the old stuff -- seems silly!  :lol:

Title: Re: Building a New Lathe
Post by: tom osselton on August 02, 2018, 01:43:16 PM
Well you will know when it doesn’t work by the castings, I use water also with my sand / bentinite but one day I would like to try a oil binder just to see the difference.
Title: Re: Building a New Lathe
Post by: vtsteam on August 02, 2018, 09:41:52 PM
Yes, Tom, that and the feel of the sand.

I started out the day today by paying a visit to Lester in the old time machine shop, to see if ha had any 1-1/8" machine collars. I doubted it, and it was true, he didn't. But I bought a 1" collar anyway, figuring to bore it out. We had a nice chat about tailstocks, and agreed that they were the most complicated piece on a lathe to build. There's a taper bore, a clearance section, a left hand thread, and a guide groove in the ram, a set over mechanism, a split collet clamp, a base, and gibs, and on my lathe the tailstock rides on the inside edges of the way channel.

Anyway I bored out the collar when I got home, and managed a 1 thou sliding fit on the new ram stock. Here checking it out against the fingers of the Gingery steady rest on the new lathe. It will serve as a stop to prevent the stock from moving off of the Lathe spindle center when boring the Morse taper.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam3.jpg)


Title: Re: Building a New Lathe
Post by: vtsteam on August 02, 2018, 09:47:16 PM
I spent much of the morning deciding how to mount and adapt the riser block to the Gingery steady rest. I finally decided to slot the base of the rest, and install Allen screws to allow me to set over the steady.

This will make boring tapers a lot easier than trying to shift the whole shebang on the ways.

I attached the riser to the ways with toe-clips on the underside. The riser is narrow enough and located to fit inside the carriage slides -- allowing the carriage to move all the way to the steady, and reducing the length of the boring bar.

Here are the base with slot and riser together on the ways:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam4.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on August 02, 2018, 09:52:25 PM
I didn't have a driver dog that would fit the new faceplate. The one I'd made for the Gingery lathe wasn't long enough to fit the wider spaced slots. So I found a piece of 1/2" square keystock, and made a new longer limb for it.

The whole dog is very simple, made up of keystock and bolts, and one nut as a keeper on the finger that engages the faceplate. That finger is a bolt with its head sawn off. The keystock is vee-notched with a three sided file to engage the work. Works quite well:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam5.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 02, 2018, 09:54:51 PM
And here's the whole setup, ready to bore. I didn't start that by evening, leaving it for another day and  fresh concentration.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam2.jpg)
Title: Re: Building a New Lathe
Post by: vintageandclassicrepairs on August 03, 2018, 04:04:25 PM
Hi Steve,
I have been following your build with interest and admiration :wave:

On the making of the tailstock I happened to notice that the thread on one of my lathes is a seperate phosphor piece fitted into the end of the ram, On the old lathe i used to have the ram was cross bored and a cylindrical PB piece fitted in,  this had the thread for the jacking screw through it
I presume this would have allowed for any minor misalignment in the casting machining or wobble in the jacking thread??
Making the threaded part seperately  also means it could be replaced when required
I remade that piece which was an interesting job !!!

John
Title: Re: Building a New Lathe
Post by: vtsteam on August 03, 2018, 05:08:53 PM
That's interesting John, I haven't seen that before. Both the Gingery and the Craftsman I own just have a threaded ram. In both there is a clearance bore between the threaded portion and the tapered portion.

I started to bore the ram today, but quickly ran into a problem using the trial and error taper adjustment method -- there was already too large a bore at the taper end (from using that same piece of stock as a bearing while boring the headstock). What I mean by too large is it is close to the finished size of the wide end of the intended taper (MT2). Therefore I can't just bore and try a MT2 tapered center to see how close I am, and then re-adjust my steady rest to get a closer angle.

I really needed to start out with a small hole, and gradually enlarge it by taper boring a small amount, blueing the MT2 taper center, trial fit it, and adjustments to the steady rest set-over according to what gets scraped off the blue. But there's a big hole, so not at all possible.

Dumb, should have realized. Oh well...... not a super big problem. I have more 1-1/8" ground stock. I just thought it would be great to use up the piece I had used elsewhere during construction.

Now if I had an MT2 reamer, and a calibrated lathe and cross slide already, I'd probably be able to make do with this piece of metal (if I was careful and lucky). But I don't. So we'll start fresh with a new piece of stock tomorrow. enthusiasm waned for this job today, because I have to break down my set-up, re-mount the chuck and drill out the center of a new piece. Then re-set up the steady, etc.
Title: Re: Building a New Lathe
Post by: PekkaNF on August 03, 2018, 06:42:03 PM
Hi Steve,
I have been following your build with interest and admiration :wave:

On the making of the tailstock I happened to notice that the thread on one of my lathes is a seperate phosphor piece fitted into the end of the ram, On the old lathe i used to have the ram was cross bored and a cylindrical PB piece fitted in,  this had the thread for the jacking screw through it
I presume this would have allowed for any minor misalignment in the casting machining or wobble in the jacking thread??
Making the threaded part seperately  also means it could be replaced when required
I remade that piece which was an interesting job !!!

John

I think my lathe has same construction, but just ironmetal insert for tailstock nut, the tread rod ejects taper tooling when retracted fully home.

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 08:15:17 AM
Yes, Pekka, if the jack screw is long enough, it ejects the tapered tool when the ram is retracted- works the same way in the Craftsman and Gingery lathes. Otherwise removal would be very difficult;

Sleeping on problems often seems to create solutions. This morning I woke up realizing that I could probably just plug the existing hole. The plug  would eventually be bored out completely......I think....I'll have to measure.
Title: Re: Building a New Lathe
Post by: PekkaNF on August 04, 2018, 09:55:49 AM
Myford ML10 has thread outside of the ram and gives a good drilling stoke in a very compact format.

(http://www.lathes.co.uk/ml10/img21.jpg)

To eject taper tool: insert a rod from the tail end and give it a gentle tap with a hammer. I found it pretty usefull. Used sometimes the hole to blow air/coolat mixture trough ER collet to remove swarf/cool the drill.

Pekka
Title: Re: Building a New Lathe
Post by: Neubert1975 on August 04, 2018, 10:16:15 AM
An other interesting, to me at least, way it rack and pinion.
if any of you know Stefan Gotteswinter on youtube he has made it on hes lathe.
https://www.youtube.com/watch?v=n1ytS1lhVFg (https://www.youtube.com/watch?v=n1ytS1lhVFg)
i have been thinking of making the same om my own lathe, that is similar to Stefan´s
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 10:19:54 PM
Interesting stuff, guys! :beer:

On this one I'm going conventional -- in fact I'm just going to copy the Craftsman ram, since that's the casting.

I started boring the taper this afternoon:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam6.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 10:44:23 PM
Trying the blued MT2 tapered center in the bore:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam7.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 10:46:39 PM
The light area towards the end means that the steady rest needs to move towards me to lessen the bore angle.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam8.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 10:48:06 PM
After adjustment, and a couple more passes, the pattern is spreading, but the steady rest still needs less set over:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam9.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 10:51:04 PM
The set over is now correct, though I need a few more passes to even out the pattern. When you reduce the set over, it cuts deeper in the back initially making a double pattern due to the springing of the necessarily thin boring bar. It evens out after a few passes at the same setting.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam10.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 10:54:49 PM
Once the angle was right, I put the blued center into the original Craftsman tailstock ram, and scribed it where they met. Then I used that to test for the proper bore depth in the new ram. When boring passes allowed the center to  reach the same line, below, I knew I had bored to proper depth.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam11.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 11:00:05 PM
Once the bore was finished, I needed to drill for the relieved section between the taper bore and the threaded back section of the tailstock ram. To re-center the steady rest, I loosened the steady's slot retaining screws, popped the MT2 center back into the tailstock and brought it up to the new ram bore. Applying a small amount of pressure with the handwheel centered the bore, and I tightened the steady rest down again.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam12.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 11:03:32 PM
Then I relieved the mid-section of the ram with a 1/2" drill bit to leave 3/4" at the rear of the ram for threading to take the jackscrew.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam13.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 04, 2018, 11:05:38 PM
And here is what the business end of the ram looked like after finisheing the taper and midsection relief:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam14.jpg)
Title: Re: Building a New Lathe
Post by: PekkaNF on August 05, 2018, 03:37:06 AM
Looks very good. Nothing wrong with the traditional construction.

Pekka
Title: Re: Building a New Lathe
Post by: vtsteam on August 05, 2018, 09:34:56 PM
Thanks Pekka.  :beer:

i had problems with threading today -- will have photos tomorrow.

I might be following john vintageandclassic's and your lathe's example...... :(
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 08:25:06 PM
Okay so some problems......

I had the taper bore all done, and now on to the simpler job of threading the other end of the tailstock ram. Piece of cake because I'd made my own Acme tap, which had done a fine job on the cross slide and the carriage half nut. It was made from the same Acme all-thread as the leadscrew, case hardened with Kasenit, and tempered to straw color in the kitchen toaster oven. Quite proud of that tap...

Here I was innocently starting the tap by hand in the lathe:

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam15.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 08:34:00 PM
Right after that photo, I unbolted the three way chuck from the faceplate, and set it on the bench. I have a monster tap handle -- about 18" across, and grabbed that one. Everything seemed to be going well for the first turn and a half, when something gave....and the tap suddenly was easy to turn -- disaster, some of the starting teeth had broken off. Or I should say, sheared off. Though the case hardening was hard enough to cut steel, the unhardened interior of the teeth just weren't up to the task. Acme form teeth really take some pressure. Perhaps if I'd made the tap with a longer lead in.... Anyway, This was a major disappointment as I really liked that tap!

So checking the damage to the bore, I figured it was only at the start of the thread, and really just a nick, so I could still try to thread it in the Craftsman. I didn't have an acme tool so I had to forge, shape, harden and temper one out of 5/16" drill rod.
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 09:43:14 PM
It's been awhile since I threaded in the lathe. Like maybe 3 years. And an inside bore Acme 1/2" screw is not a favorite threading task. So I renewed the joys of searching for the right change gears, squinting to try to read the layout chart on the inside cover of the gear housing, getting blackened grease on arms, clothes and, as I discovered later at my family's surprised smiles, face.  :loco:

With the gears finally set up properly, I pulled out the pin in the bull gear, flipped the gear engagement lever, checked for proper carriage travel direction, set the compound to 14 degrees with a magnifying glass, and loosened and engaged the thread dial with the leadscrew. I checked that the tool was square to travel, moved the cutter to the bore start, zeroed the two slide dials, and finally started a cut.

Well, things were going okay, at the the lowest speed the Craftsman was capable of. I was starting to think I hadn't lost the touch. The only problem was, I hadn't figured out what the compound's depth of cut should be for a 10TPI Acme thread at 14-/2 degrees compound. But Being the try and fit type, I did have my somewhat wounded tap, which I'd ground back a little, and I figured I would just test the bore periodically with that. Once it was close, I could use the undamaged part of the tap to make the final cut.

Things went well and the tap showed promise of getting near to the end of lathe threading. I was able to screw it in 1, then 2, then 3 turns with the lathe stopped. I kept working it in, and then backing off, gaining ground bit by bit, though it seemed to be getting tighter. But I felt the end was in sight so I applied a little more pressure -- not enough to break anything, but definitely putting some pressure on. It moved a little when I bumped it with my hand, but it never seemed to break through.

Then I noticed I was turning the whole workpiece in the chuck jaws. I guess I hadn't tightened those enough to resist this kind of mistreatment. So I was well, screwed ......again. The tap couldn't cut it, and now the threads were out of register with the lathe threading dial. I did the usual mistaken last hope in this situation -- trying to re-align the tool and slides and threading dial while taking the backlash out of the gear train. But as usual, all I managed to do was mess up the threads.

Time for a break!  :loco:
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 09:46:49 PM
So, what to do, what to do. I didn't fancy boring a new tailstock ram. Hmmmmmm. Wait a minute Didn't Vintage and Classic, Pekka, Neubert on this very forum mention using an insert for the threads in lathe rams? Why yes, they did!

Of course....  :nrocks: :nrocks: :nrocks:
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 09:52:11 PM
So, on with the show.....

Bore out the old wrecked threads and open out to .7495"

Check.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam16.jpg)
Title: Re: Building a New Lathe
Post by: S. Heslop on August 06, 2018, 09:59:28 PM
No hope of finishing up the mostly cut threads with what was left of the mangled tap?
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 10:38:54 PM
Sorry to say Simon, no the tap wouldn't budge further. I later found the cause to be that the relief section was slightly eccentric, because it had only been drilled (not bored). This jammed the tap, I believe. The relief section was a tricky problem, because I wanted to preserve the Morse taper's small end (as much as possible) yet relieve for a 1/2" jack screw at the other end. This really required an odd size drill that I don't have. I have a full range up to 1/2", but then it jumps to 5/8". Unfortunately, 5/8" would eliminate a lot of the narrow end of the Morse #2 taper. I was hoping that an older 1/2" drill, cutting a little oversize, would work in the hardest to reach section of the relief bore. But obviously, it didn't.

Anyway, I forged ahead with the insert plan, I found an old piece of 1" OD bronze bearing material that I had bought years ago, and never used. It coincidentally was bored almost exactly to the tap drill size for a 1/2" 10 TPI Acme thread. Sheer luck!

So I chucked that up in the lathe and started turning the outside down to get a light press fit in the tailstock ram.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam17.jpg)

Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 10:46:06 PM
While turning, I noticed its bore was not on center with the OD. Since I had to consider that bore as final, I stopped the lathe, and readjusted the chuck off-center to match the bearing bore. This proved out one of the really great advantages of my faceplate-3-jaw chuck setup! It was a piece of cake to clock in the bore, rather than the OD.

Then I continued turning the outside down, I got it to .750 and parted it off.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam18.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 10:52:27 PM
I went through a repeat of the lathe threading routine on the Craftsman -- a lot easier with the lathe already set up, and the earlier experience under my belt. I was able to use the old tap, as well to do the final thread sizing. Since the tap is made of the same screw material I will be using, the clearance is very close, with almost no backlash.

It was also at about this time that I figured out that the slightly eccentric and relatively close relief bore was probably the cause of my earlier problems.

Of course since this insert wasn't in the ram, the tap couldn't jam. And the threading was easily accomplished.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam20.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 06, 2018, 10:57:22 PM
And finally a trial fit -- it does seem to be a slight interference fit. I didn't drive it home, because I want to clear out the relief bore -- no sense having the jack screw binding. I guess I'll have to make up a longer boring bar to do it. Might take a while because of springing, but at least this part of the process will be finished.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam19.jpg)
Title: Re: Building a New Lathe
Post by: awemawson on August 07, 2018, 02:00:57 AM
Persistence pays off, well done Steve  :thumbup:

Title: Re: Building a New Lathe
Post by: PekkaNF on August 07, 2018, 02:57:18 AM
Good Job. Pretty confident that the insert works out better than the original plan!

Pekka
Title: Re: Building a New Lathe
Post by: Neubert1975 on August 07, 2018, 07:34:36 AM
Nice work, as always ;-)
Good to see that you managed to make it work  :thumbup: :beer:

And now i will go out i my HOT workshop and continue with project mill power feeder.
Title: Re: Building a New Lathe
Post by: vtsteam on August 08, 2018, 09:27:13 PM
Thanks Andrew, Pekka, Neubert!  :beer: :beer: :beer:

I bored the recess wider, and it was definitely slow going with such a thin long bar, but it did cut, and after a trial fit with a piece of acme all-thread, there was enough clearance to press the insert home.

Next step was to start on the jack screw. I cut off a 6" length of Acme rod, chucked it in the 3 jaw, and began turning the threads off of a 2-1/2" section. That will be the part that passes trough the tailstock end cap, and will accept the handwheel.

I had the tailstock itself apart, so couldn't use it as a support center for turning off the threads. So I had to take light cuits.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam21.jpg)
Title: Re: Building a New Lathe
Post by: vtsteam on August 08, 2018, 09:32:08 PM
But I got there eventually, and it was nice to have the three tailstock ram pieces together and functional.

(http://www.sredmond.com/vtsteam/Lathe/TailstockRam22.jpg)

I still need to make up thrust bearings for the jack screw, and mill a groove along the ram to complete these components. But not today. :beer:
Title: Re: Building a New Lathe
Post by: Neubert1975 on November 05, 2018, 01:16:17 PM
any progress on this nice project ?  :beer: