Building a New Lathe

[vtsteam]

The base after turning.

 

There's a land near the outer edge that the top slide rides on, the inner part is relieved. Finish isn't perfect, as the insert wasn't ideal, and the slight regular groove pattern inside probably is a result of hand cranking -- I probably need to tighten cross slide gibs. But still, pretty good considering a first trial of a newly built lathe in a difficult material and shape. 

[PK]

That has to be a good feeling. Well done..

[RotarySMP]

Hell of an achievement to manufacture a whole lathe. Good on you.
Mark

[Neubert1975]

Greate to see it in use.
well done, must feel good to try it out 

[awemawson]

Cracking good job Steve 

At least you don't have to worry about chasing obsolete documentation and parts like the stuff I work on 

[vtsteam]

Thank you guys kindly! 

[S. Heslop]

Fantastic! I didn't even notice it was being turned on the homemade lathe till I read the text. I guess that might say something about how professional it looks!

[tom osselton]

Glad to see it all come together well done!

[vtsteam]

Thanks Steve, Tom,  I'm very happy to have built one instead of buying one as I'd originally set out to do in this thread. Though I never thought it would be a few years in the doing. I'm looking forward to the day when I can build engines with it.

Well, it's not finished quite yet, but the end is in sight.

Today I fitted the three jaw chuck to the faceplate. Three easily accessible hex bolts fit in the slots. Tighten lightly, put a clock on the work (a new tailstock ram), rotate by hand and tap the chuck with a wooden mallet to read half the difference between high and low readings, rotate again to check. In about 30 seconds it's turning within half a thou. Tighten the bolts and you're done.

I don't know how long it takes to adjust a Set-Tru or other proprietary chuck system, I do know how long it takes to center a 4 jaw chuck, even with the two key method. I think this simple system may be faster and easier.

I guess you could say I just have a larger diameter backplate than most lathes -- one that's more useful on it's own, too. And a register would just restrict my ability to clock it in to true center for any size work, and no matter what the scroll wear. I thought about making a thin chuck register plate to to fit on the faceplate, but have decided against it as actually less accurate, in the long run. Why lock the chuck into one permanent position?

I like the fact that I can use a regular crescent wrench and hex bolts above the headstock too, rather than trying to fit an Allen wrench in behind the spindle flange, as is done on the Asian mini-lathes. Much easier with a bigger backplate er...faceplate.

[vtsteam]

I borrowed the tailstock ram and lock, guide, and wheel handle out of my Craftsman and temporarily installed them into the new lathe's tailstock casting. That allows me to use the new lathe to start making its own ram and tailstock hardware. I fitted a Jacobs chuck to the tailstock and began the first drilling operation, preparatory to boring a Morse taper in the end.

Drilling:

[vtsteam]

I need a steady rest to do the taper boring, and I remembered I had bought an old one at the Bernardston Gas Engine show a number of years ago. I found it in a crate of other goodies after a short search and set it up onto the ways to compare its center to the headstock center. It was an inch tall, so it must have been for an 11" lathe.

[vtsteam]

One leg was longer than other other, and one leg had a notch for prismatic ways. I marked it for cutting an inch off, and realized that would just leave the bottom web of the casting, for a nice wide flat surface.

It took a long while to figure out how to mount the casting on my 4x6 bandsaw, but some holes I'd tapoped came in handy for clamping it on top of the standard vise with some mill toe clamps and studs.

[vtsteam]

Legs sawn off.





I then took it to the mill to surface the bottom.

[vtsteam]

Unfortunately, when I re-assembled it, this steady rest turned out to be one of the worst examples of domestic casting I've ever seen. Not that the castings themselves were all that bad, but the fit and finish were horrendous. For one thing, the fingers were very roughly cast with the draft still present (not milled out), irregularly shaped on probably a belt sander (linisher?) and they were different thicknesses and didn't meet in a flat plane.

[vtsteam]

Besides the different thicknesses of the fingers, the main casting channels had never been milled. They looked like someone had molded them with bubble gum. The irregularities added to the mismatch of the fingers, and keeping them in one plane was impossible.

[vtsteam]

I considered milling the slots, but without a rotary table, that would have taken a long time to accomplish on such odd shaped castings. there were no planes to work from, and I'd have needed three odd setups.

Likewise the fingers, being wedge shaped in section, might not have fit well if milled square and flat. I could have made new ones, but this was turning into a major project. I did try to even out the slots with a die grinder, by hand, and I tried the fingers in different positions to get the best fit, and then stamped each one for easier replacement.

But at the end of the day, I decided to put the steady back in the odds and ends box as a total rehab project for another day (and a rotary table).

Instead I decided to use the steady I had made for my Gingery lathe. It needed only a 7/8" riser block. In a half hour before dinner I'd cast one in aluminum. Working fast,  I set the crucible full of old sprues in the tiny furnace, turned up the gas, cut a block of pine to the right size, and rammed it up without even applying a finish, and by the time the mould was ready, the metal was hot and ready to pour.

I forgot how nice aluminum is compared to Zamac. It comes out shiny like a new dime. It hardly shrinks at all, by comparison, and the casting comes out mostly sand free. I've thought about this -- Zamac is much more dense, and I believe sand may tend to float in it. Sand doesn't float in aluminum, I don't believe. Aluminum is also so much easier to cut with a hacksaw and file. A pleasure to work with, by comparison.

The shake out:

[WeldingRod]

I made a follow rest a while ago using two layers of plasma cut plates.  I set things up so that I welded the layers together and then sawed off a section that was keeping all the slots right.  For that application I actually wanted the fingers in two different planes, so there were finger slots on both layers.  Worked really well!
I, um, might have made two of them because I didn't really understand what a follow rest really needed to look like...  the second one worked really well ;-)

Sent from my SAMSUNG-SM-G891A using Tapatalk

[krv3000]

coming a long well that support casting the panted on looks just as bad as these castings from Stuart wood be nice to see you make an engine on that lathe   

[tom osselton]

That is a horrid casting you would have thought they’d catch that at the factory.
I never have seen you recondition your sand is it linseed based?

[vtsteam]

WR, that sounds interesting. I have a follower rest that I bought at the same time as the steady. But much better casting. Not sure what lathe it went to, but I will probably adapt it some time, if I can. But for now, I need a steady rest. 

Bob, I'm really excited to get going on engines as soon as I get the tailstock and top slide done. Shouldn't be too long now. You've done great stuff with those Stuart castings. Just goes to show you can always make something interesting and perfectly usable out of any kind of metal problem. All you really need is the desire and that can-do attitude. Metal will always yield to a person with determination! 

Tom, funny you should mention my greensand and reconditioning. I just use plain sand and fire clay (and water for non-ferrous casting. Nothing special. The fire clay I can get here (in Vermont) now is called "Hawthorn". Ceramics people use it.

But the funny part is, This is the same greensand I first mixed up in 2002 to build my Gingery lathe. It started out as about 100 lbs, and is now down to 50.

Yup, I've used the same greensand batch for 16 years, and for countless castings, including all of the present lathe, besides the Gingery and accessories.

However, I did think it was getting a little tired lately, so just before I cast the last aluminum riser block above, i added 5 quarts of new sand, and 2 quarts of fire clay. That brought it up in volume some, too. So your question is extremely timely!

I think you really meant, what do I use for liquid -- and that is plain water -- I use a spray bottle to evenly dampen the top surface of the sand, then trowel it under and repeat, until the sand feels right. Then I cast. I go entirely by feel of the sand.

I will say, that it still doesn't feel as good as it used to, and the castings don't look quite as good, so we'll see if this new addition really helps, or whether I should just discard it and start over. I do worry that new sand won't quite be the same as my old standby, and I actually feel a little nostalgic about the old stuff -- seems silly! 

[tom osselton]

Well you will know when it doesn’t work by the castings, I use water also with my sand / bentinite but one day I would like to try a oil binder just to see the difference.

[vtsteam]

Yes, Tom, that and the feel of the sand.

I started out the day today by paying a visit to Lester in the old time machine shop, to see if ha had any 1-1/8" machine collars. I doubted it, and it was true, he didn't. But I bought a 1" collar anyway, figuring to bore it out. We had a nice chat about tailstocks, and agreed that they were the most complicated piece on a lathe to build. There's a taper bore, a clearance section, a left hand thread, and a guide groove in the ram, a set over mechanism, a split collet clamp, a base, and gibs, and on my lathe the tailstock rides on the inside edges of the way channel.

Anyway I bored out the collar when I got home, and managed a 1 thou sliding fit on the new ram stock. Here checking it out against the fingers of the Gingery steady rest on the new lathe. It will serve as a stop to prevent the stock from moving off of the Lathe spindle center when boring the Morse taper.

[vtsteam]

I spent much of the morning deciding how to mount and adapt the riser block to the Gingery steady rest. I finally decided to slot the base of the rest, and install Allen screws to allow me to set over the steady.

This will make boring tapers a lot easier than trying to shift the whole shebang on the ways.

I attached the riser to the ways with toe-clips on the underside. The riser is narrow enough and located to fit inside the carriage slides -- allowing the carriage to move all the way to the steady, and reducing the length of the boring bar.

Here are the base with slot and riser together on the ways:

[vtsteam]

I didn't have a driver dog that would fit the new faceplate. The one I'd made for the Gingery lathe wasn't long enough to fit the wider spaced slots. So I found a piece of 1/2" square keystock, and made a new longer limb for it.

The whole dog is very simple, made up of keystock and bolts, and one nut as a keeper on the finger that engages the faceplate. That finger is a bolt with its head sawn off. The keystock is vee-notched with a three sided file to engage the work. Works quite well:

[vtsteam]

And here's the whole setup, ready to bore. I didn't start that by evening, leaving it for another day and  fresh concentration.