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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: JonIndigoman 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: JonIndigoman 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 July 09, 2017, 10:21:42 AM
Thread on hold due to Photobucket image destruction in this and other threads.

I would like to see a reasonably quick means (script or forum function) for users to globally alter their past image links to reflect a new host of their choosing.

I would also like to see the ability to edit past posts be provided to all users.
Title: Re: Building a New Lathe
Post by: vtsteam on July 11, 2017, 01:24:53 PM
Currently repairing photos in this thread.........
Title: Re: Building a New Lathe
Post by: vtsteam on July 11, 2017, 04:27:14 PM
Okay, all photos restored, back on track. That took the better party of a day! Thanks PhotoBucket  :wack:
Title: Re: Building a New Lathe
Post by: Homebrewer on August 07, 2017, 07:25:09 PM
Tag.

:(