Author Topic: Building a New Lathe  (Read 135682 times)

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #625 on: July 12, 2018, 02:22:17 PM »
The punch worked to move the hole center over from the peg location:


I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #626 on: July 12, 2018, 02:23:39 PM »
I drilled 1/8" through with a spotting drill -- I didn't want to risk another broken 1/16" bit in this tough steel faceplate.


I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #627 on: July 12, 2018, 02:25:05 PM »
The hole center checked out whan I replaced the plug gauge. The new hole is at about 10:00 position in this photo (marked "3").


I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #628 on: July 12, 2018, 02:28:14 PM »
And finally, I drilled it out to a #7 drill -- the tapping size. This fully removed the peg I'd put in, and there is no evidence of my scew-up earlier.

Really happy that worked!  :ddb: :ddb: :ddb:




I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline S. Heslop

  • Hero Member
  • *****
  • Posts: 972
  • Country: gb
  • Newcastle Upon Tyne
Re: Building a New Lathe
« Reply #629 on: July 12, 2018, 02:39:48 PM »
Nice save!

Offline Neubert1975

  • Jr. Member
  • **
  • Posts: 59
  • Country: dk
Re: Building a New Lathe
« Reply #630 on: July 12, 2018, 03:06:39 PM »
what a day i had, but at least i now know iŽam not the only one that experiences those days.
as i always say when i have days like yours, tomorrow is  better ;-)

i dont know if its of any use, but i have learned that if i have to hit spot on in a hole or a punch mark, than i place the drille (in a drille press) over the hole. and by hand reverse the drill while lightley pressing with the drille press, then it will center.

 :beer:

Offline Neubert1975

  • Jr. Member
  • **
  • Posts: 59
  • Country: dk
Re: Building a New Lathe
« Reply #631 on: July 12, 2018, 03:21:25 PM »
Nice save, and nice work  :thumbup: :beer:

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #632 on: July 12, 2018, 06:48:21 PM »
Thanks Simon and Neubert.  :beer: Sure glad it worked! Happier today than yesterday, for sure.

I tapped the two remaining holes today, and man that steel is tough. Nearly an inch thick, too. I was beginning to wonder if I'd break the tap, for my next dufus performance. But I went slow -- sometimes only an eighth of a turn before backing. I got through it.

I was a little surprised to find out that the flywheel fit on only one way, with those three holes. The spindle flange itself is not perfectly drilled, apparently, and I copied that in my plug gauge. Oh well, at least it goes on one way. I stamped numbers at the holes in the flange and the face plate, so I could put them together more easily in the future.

I mounted everything, now bolted together, and it spins nicely in the bearings. So I tried one other thing that I think I  mentioned a way back in this thread. That is, mounting my new 5" three-jaw chuck directly to the faceplate. It's very simple to add. Three flange head hex bolts through the faceplate slots.




The chuck is easily adjustable to center with a DTI -- just make the bolts finger tight, then rotate the chuck by hand, and tap the high side lightly with a wooden mallet until centered. Then tighten the three bolts. It's very quick. You can tighten the bolts with a socket wrench -- the headstock clears the bolts on the side.

I think this is going to be my standard chuck mounting method. While I could have made the usual backplate adapter for the chuck, it would have to extend out from the headstock the same distance that it does on the face plate. The spindle flange is deeply inset into the face plate to reduce overhang. So it's the same as a backplate.

It would be a lot harder to change over with a backplate adapter than with the faceplate-- not much space for an allen wrench behind the spindle flange, and they're much harder to manipulate back there.

With the way I have it now, I can also easily remove the chuck (with work in it) to bring to the mill, and then replace it using the DTI-mallet method again.

I think this is going to work well for me.  :thumbup:

I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #633 on: July 12, 2018, 09:36:48 PM »
I should add that I'll probably drill three holes in the faceplate rather than use the present slot mount so it's a closer fit on the bolts. And I might make a thin disk to fit the rear register of the chuck, and dowel pin that to the faceplate and include a retaining screw for it. That would be easily removable when using the faceplate alone. Then chuck replacement will be repeatable. But for now I'll probably just use it as is.

Getting very close to being able to turn with it. Next up is drilling and tapping the top of the cross slide to take tool holders, accessories, compound slide, T-bars, etc. I haven't yet decided on a hole pattern, but will probably do that tomorrow. This is getting exciting for me! :dremel:
« Last Edit: July 12, 2018, 10:50:15 PM by vtsteam »
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 6193
  • Country: gb
  • East Sussex, UK
Re: Building a New Lathe
« Reply #634 on: July 13, 2018, 01:34:23 AM »
Then all you need is a set of radially drilled holes on the edge of the face plate, and a suitable detente pin, and you have a nice simple.dividing set up
Andrew Mawson
East Sussex

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #635 on: July 13, 2018, 10:12:22 AM »
Well, I was thinking about doing that with the spindle pulley, Andrew, as was done on the Craftsman. But certainly do-able either way...... or both.  Maybe even with a pin vernier, like the collet spinner has.

But that's future stuff. Gotta concentrate on the basics for now. No tool holder, and no operable tailstock ram yet.











I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #636 on: July 13, 2018, 01:08:15 PM »
Ughhhh, I spent the morning looking at ten other lathe's cross slide patterns, tool posts, ways of doing things and my head is spinning trying to figure out just what holes to put in that cross slide, where, and what size and thread, etc.  :doh:

It's a lot easier to add stuff within the limitations of something you already have, than to just start drilling into a blank slate. I've got too many what ifs floating around in my mind. I gotta take a break. Have to get the truck inspected anyway. I'm outta here.
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline ddmckee54

  • Jr. Member
  • **
  • Posts: 46
  • Country: 00
Re: Building a New Lathe
« Reply #637 on: July 13, 2018, 02:40:50 PM »
Yup, not building something until you've got the BEST design often results in it not getting built - DAMHIK.

If all else fails, write your designs down on slips of paper, throw them in an hat, close your eyes and pick one.  As you said, you can always add stuff to make it better; and it's not like you have to look very far to find a foundry that can cast new parts for you if you need them.

Don
Too many irons, not enough fire.

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #638 on: July 13, 2018, 02:58:30 PM »
Thanks Don! :beer:
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #639 on: July 13, 2018, 09:09:47 PM »
I think it's going to be a grid of .25" tapped holes on 1-1/2" centers.  :zap:


I'll screw in six Tee sectioned bars over that 1-1/4" x 1/2" to make up just a plain set of 5 Tee slots oriented across the carriage. Then anything else can be fastened down onto that.

Since this is a 9" lathe, I have a little more leeway for center height than a typical 7" mini lathe.

In fact I do need to pad up a fair amount to get tools near enough to center height.
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #640 on: July 14, 2018, 01:49:00 PM »
Nope, changed mind again. Not 1-1/2" square grid, but 1-3/8" by 1-1/2" rectangular grid. That will let me use 1" wide Tee bars instead of 1-1/8" -- an odd size.

I'm busy tapping 18 holes, now. Undecided whether to mill mill out steel Tee bars, or cast them in zamak. Since it's the weekend and I don't have the steel, and I'm an impatient cuss, probably the latter.
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 6193
  • Country: gb
  • East Sussex, UK
Re: Building a New Lathe
« Reply #641 on: July 14, 2018, 02:49:08 PM »
I suppose in the event of a calamity the Zamak could be a useful 'fuse-able link' and Tee bolts will pull though it rather than break something else.

Andrew Mawson
East Sussex

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #642 on: July 14, 2018, 07:35:39 PM »
Well maybe not, Andrew -- it's stronger than cast iron, certainly in tension -- so not disadvantaged by most standard CI tee-slotted tables. Probably it would shear the 1/4" screws holding the tees down, as my own guess. They have a 3/4" bury in the table. Think a substance a little short of aluminum bronze, and you'll get a feel for it.

Of course I'm going to try to avoid inadvertent destructive testing!  :zap:  :beer:

I spent the day first tapping the holes, and then tuning up the cross slide. There were a lot of small details I'd left, and one forgotten step.

That last oversight was forgetting to run a hacksaw blade down the inside corner of the wear pads.  :palm:

Because I'd milled this slide, rather than filed and scraped it, as I had my earlier lathe, Gingery book in hand, I had forgotten to do this. Y'see, no endmill, no matter how sharp and new is going to maintain a perfect inside corner. With square ways, you have to cut out the tiny radius a mill will leave, so the pads are separated and contact the ways properly. The Gingery way is just run a hacksaw blade in the corner at 45 degrees until there's a small slot.

Anyway I realized my oversight when I took the slide apart, and found a 1 thou shim on that side only. Weird to shim one side, if the whole thing was done at one setting in the mill. Well the corner radius was responsible, and as soon as I made  the proper cut, the shim was no longer necessary. And of course the slide worked better, too!

Other tune-ups involved shortening the over-long gib screws, and fastening the cross slide leadscrew bearing in place with two flat-head screws. and squaring the slide to the ways.

The carriage now moves silky smooth, without wobble in any direction.
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline S. Heslop

  • Hero Member
  • *****
  • Posts: 972
  • Country: gb
  • Newcastle Upon Tyne
Re: Building a New Lathe
« Reply #643 on: July 14, 2018, 07:44:47 PM »
Are there any disadvantages with zamak? What I mean is, why isn't it used more.

Offline vtsteam

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5313
  • Country: us
  • Republic of Vermont
    • www. sredmond.com
Re: Building a New Lathe
« Reply #644 on: July 14, 2018, 09:13:13 PM »
Simon, It's a real pain to machine, saw, file, or scrape. The only operation I've done with it that goes nicely, is tapping, for some reason. Boring holes is the worst. You need carbide for sand casting machining.

Now I know that hard machining qualities goes against the experience of other people, and maybe the alloy variety I've been making up is different than the variety they use. I dunno. But I believe my ZA-12 is correct. I'm using purchased virgin zinc ingots, and mixing in the right amount and type of aluminum (see the recipe, somewhere way back in this thread.)

I was using purchased ZA-2 earlier in the lathe construction (ie. years ago!) -- not mixing that myself -- and it seems to me that it was better/easier to work with than ZA-12. But I can't remember for sure.

The other negative thing is that it goes dull with age. I don't find that such a problem, as I intended to paint the lathe all along -- steel and iron rust, especially in the winter environment here, unless constantly used and oiled. Condensation does it. So it's just a different but similar problem.

And the ZA-12, at least, has huge shrinkage, when casting in sand. You really have to plan for that. It'll suck a hole right down the full length of a sprue. I'm thinking ZA-2 didn't do that as much. I'm going to have to try to do a comparison -- I think I have one ingot of ZA-2 left.

On the positive side, it is tremendously strong, solid, heavy, melts at the lowest temperature of the common structural metals, it's inexpensive, easy to cast (other then the shrinkage problem). I imagine it has excellent vibration damping qualities. It's very dense, but somehow, I dunno, "fluid" seeming

Oh also it's an excellent bearing material, unlike aluminum, or steel. So making lathe slides out of it is a really good choice, in my opinion. And the headstock feels massive and sturdy. My lathe is hard for me to even slide on the bench now, it's so heavy. The opposite of aluminum.

Well those are my experiences, anyway.
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline S. Heslop

  • Hero Member
  • *****
  • Posts: 972
  • Country: gb
  • Newcastle Upon Tyne
Re: Building a New Lathe
« Reply #645 on: July 14, 2018, 10:42:38 PM »
That's interesting to read. I've heard of it before in the context of bearings and also in a few older lathes switching over to zamak parts, implied as a cost cutting measure. So I was thinking of it in my head as the classic mystery pot metal and not really a useful structural material compared to aluminium. It's low melting point definitely makes it worth keeping note of.

Offline Fergus OMore

  • Hero Member
  • *****
  • Posts: 986
Re: Building a New Lathe
« Reply #646 on: July 15, 2018, 04:11:46 AM »
Simon

'Chinese metal' appears regularly in such things as vehicle carburetors and in model engineering, the feed nuts on Myfords are a zinc alloy.

One fault is that it does corrode until after a certain point it will be nothing more than white fluff! Chemically, it is somewhat worse than cheap brass.

However, it is easy to cast and I have rather a nice Unimat clone lathe made from -- lots of it.

Probably 'metal' for typesetting is something similar.

I hope that I haven't stolen the original post-- but Simon did ask

Norman

Offline seadog

  • Full Member
  • ***
  • Posts: 152
  • Country: gb
  • NE London
Re: Building a New Lathe
« Reply #647 on: July 15, 2018, 05:09:00 AM »
That would be Mazak, Fergus.

Offline Neubert1975

  • Jr. Member
  • **
  • Posts: 59
  • Country: dk
Re: Building a New Lathe
« Reply #648 on: July 15, 2018, 07:24:57 AM »
 :beer: ;-)

Offline Fergus OMore

  • Hero Member
  • *****
  • Posts: 986
Re: Building a New Lathe
« Reply #649 on: July 15, 2018, 07:59:58 AM »
:beer: ;-)

I thought that I'd written about this - before my world was thrown topsy turvy.

Ah well, it's an absorbing post- thanks

Norm