Want to build a lathe

[Fixee]

For some time now, I've been a lurker becoming ever more impressed with can be done with some effort and ingenuity. Some of the projects displayed are really WOW.

Regarding me, I'm bit like the cat with 9 lives, at least some of which should be helpful as I move forward on my project. I've worked professionally in the construction trades, as a programmer and system engineer, and in several roles consulting on logistical improvements.

I've been around long enough to know that being well educated doesn't make me smart. IMO, the best way to have good ideas is to have lots of ideas (regardless from where they come).

One of the loves of my life is bicycling, and I make own own custom frames, both from steel and from carbon fiber. Part of the drive to obtain a lathe (and eventually a mill) is create jigging and fixtures for framebuilding. Having said that, as the range of options opens up to me, I'm looking to a number of other projects as well.

The goal of this thread is to be document the planning/design/build process, and soliciitate ideas from all of you.

Just to set expectations from the beginning, this will probably be multi-year effort for a number of reasons. Anyhow, all are welcome to join in how best they prefer.

[Fixee]

There are certain requirements for this lathe which I consider absolute, and many other optional possibilities. Together, these for the Design Guidelines. So lets go through a few.

I want to be able to turn down the seat for the crown-race of the steerer. This requires a spindle bore of at least 1.25 inches, and preferably one of 1.5 inches. In fact, I think that most older salvage headstocks from US machines will be light in the spindle bore. So there is a good chance that I will need to manufacture my spindle, or subcontract the construction of same.

I have looked at the cost of asian replacement spindles, and they arent' cheap when one gets above the 7x12s. Moreover, I'm not sure the quality is there. I need to get some more current ANSI lathe specs, but comparing a 1945 set of ANSI specs with claims of a better regarded asian clone wasn't impressive (for the clone).

My intended bed is Expox/Aggregate. Shouldn't be hard to get good results at home - particularly with a little planning.

The motor would be a vaiable speed drive w/belt dryive to the spindle to help isoate vibrations. I want the final machine to be smooth running an ridgid.

Ifigure this to be a nominal 10.5" x 30". but to have actual clearance of 13" on the swing. For my purposes, 2 hp should be sufficient, but rigidity should sufficient to handle a5hp motor.

Given the CNC advantages, even if he manual modes, I expect to sue NC functiosn. So, for exmple, no compound which adds weight, height, complexity, cost, soure of error.

Finally, let me close by noting that I'm in hospital with a staph infection. So if there are egregious mis-spellings, or poor sentences, Please do let that throw you off, we'll all be speeked thsame soon.

Best regrds
Fixee

[Fixee]

While there is much recovery yet to be had I was released from hospital yesterday - hence feel more human and back to planning this project .

I've noted before that this is probably a multi year build project. My goal would be to build a machine as accurate and capable as a like-new Monarch 10EE, only with CNC capabilities. Oh, and mine would have a considerably larger between spindles measurement. Given what a 10EE weighs, I'm not sure I'll fully hit the target, but its what I'm shooting for.

So far, of the basic CAD packages, I prefer Alibre, but want to get in for a closer test of Dolphin. So far, my second runner up in BobCAD, mostly for the CAM - not the drawing process. If anyone has strong thoughts about inexpensive CAD and/or CAM packages for use in context with a lathe?

Having never built a machine tool, nor run a CNC tool, its clearly time to focus on baby steps. To these ends, I'm planning for one or more smaller lathe projects to come first. I'm still working to lay down specs for a first smaller lather, probably based on an A36 C channel dampened with E/A, and using either a new 7x? headstock, or perhaps one off a Logan/SB/Clausihg.

So here are a few more baby questions:
1) I'm considering pinning steel plates to the ends of the C channel, but is there a reason it would need some tabs welded across the bottom? My guess is that on a 7x20 machine, the answer is no, but thought I'd ask early.
2) Shopping linear guides on ebay, mostly used, to keep the training budget down. Most listings don't give anything close to full model codes, or even currently accurate codes. I'd like to make an accurate machine, but it seems impossible to ascertain the accuracy (just the as-produced, clearly wear will come into play). So...Is it just a matter of patiently waiting, or should I just assume that anything based on 15mm rails will be accurate for this size of lathe? Please advise.

Thanks all!

[Fixee]

Here's a pic of any early study for a composite lathe bed. It'll be a while until I come up with more current one because I have to learn FEA software to analyze it.

[Fixee]

I've been taking some time, over the last few days, to soak up info regarding components and design.

The picture from the last post is from an early attempt to workout spacing for linear rails and bearings. It predates realization that the cross slide and tail stock can be on one set of rails. The tail stock won't be powered, so it just needs the bearings to locate to the spindle axises.

Part of my calculations are whether I'll get the rigidity I want using 3 or 4 blocks for each of the cross slide and tailstock. I suspect that's possible, and that it might simplify alignments (3 points defining a plane and all that). Also, I suspect that I can bring the two platforms closer together using triangles of blocks, where one has 2 blocks on the front rail and the other has two blocks on the rear rail. Anyone with vis a vis this decision variable, please chime in

Much time has gone into reviewing some of the impressive build records here. Once completed, I will truly be able to stay that I've stood on the shoulders of giants. There is just so much rich information re all aspects of building.

That said, I'd prefer to maintain a somewhat traditional look, so no slant-bed designs. Originally, the concept was to run a ball screw between the rails and under the headstock. This would keep it symmetrically mounted, which always seems like a nice idea. Looking at others, This isn't a common approach, partly due to space, and I'm guessing partly due to keeping it out of the swarf.

All of which leads me to think that provisioning for ball screws needs to be an early part of the design process. Either stick them out of the way and deal with asymmetrical loads, or do the hard work of sizing, locating, and building the bed and headstock design around them. If anyone's experience disagrees with this assessment, please feel free to chime in.

I'm also finding more hardware resources on the web than expected, some of which look very attractive. For example, Nook has a nice website in terms of quickly describing the accuracy grades of ball-screws and linear guides, and even suggesting appropriate combo, by axis, for various kinds of machinery. I do wish they spoke more about themselves and their business.

I've also found Rockford Ballscrew and their related Rockford Linear Motion. They're in driving distance and sound like nice folks with which to do business. Deals on ebay are great, but so much of whats offered appears to be a crapshoot in terms of used, inadequate product description, shipping from far away, etc. So, if i get lucky with ebay great, but its good to know that other solutions are close at hand.

If anyone has experience working with Nook or Rockford, please share it here. I'd like to hear the good and the bad, but like the idea of using US manufactured product where possible. And yes, I realize that some big-name non-US companies are doing production in the US. That just doesn't feel quite the same to me.

I'm now going back into some sections of the Zone with the hope of better validating my sizing assumptions re guides and ballscrews. Perhaps by next week I'll have sizes and grades sorted out, both for my goal machine, and for a beginner machine that will help acquire skills and knowledge for the goal machine to be a success.

Peace out,

Fixee

[MrWild]

Have you done a cost analysis yet? With a head stock bore that large, you are talking industrial size. The building costs will run more than if you bought a used one and converted it to CNC.

[Fixee]

Hey MrWild,

Good points, you have my total concurrence. I have been looking at possibilities for conversion or re-purposing of a used headstock.

The larger financial analysis is still in the WAG stage, but getting more detailed every day. Much of the electromechanics can be priced pretty well online (albeit still cranking numbers re needs, so costs need to wait on that). I found some baseline retail (onsie/twosie) linear guide costs. Need to crank some more numbers on composite mfg, but waiting until the design is better fleshed out. I've done enough with composites and CF that this part doesn't scare me.

Looking at mill spindles (compared to lathes), there seems to be a much larger available supply, both NOS and used but clean. Which doesn't rule out the used headstock approach - just a bit more work.

Only recently have I found what seem to be suitable sources for a custom spindle/headstock. I'm going to search a little further before selecting vendors, initiating discussions, or submitting RFPs.

Time will tell, but given the design goals, this isn't going to be a cheap lathe. Then again, I hope it will be cheap compared to purchasing these capabilities in a production unit.

Any other questions or insights?

Cheers,

Fixee

[S_J_H]

My goal would be to build a machine as accurate and capable as a like-new Monarch 10EE, only with CNC capabilities. Oh, and mine would have a considerably larger between spindles measurement. Given what a 10EE weighs, I'm not sure I'll fully hit the target, but its what I'm shooting for.

Whoaa...Were you on some good strong narcotics when you wrote that?

The 10ee was and still is one of the finest manual tool room lathes ever made. The 10ee had a standard spindle run out of 40 millionth's of an inch and a even more accurate 30 millionth's as an option and the headstock has exceptional rigidity. They were built with supreme accuracy, fit and finish. A new one will set you back around $80,000.

There is just no way to build a headstock of the size and quality to equal that of a newly spec'd 10ee unless you are a very wealthy man to fund such an ambitious effort.

I totally agree that you should tackle building a small lathe first. Even a small lathe is a lot of work to build to a high accuracy level.

Metal Lathe bed ways should be accurate and parallel to the spindle to at least .0002" over 10" in length in order to call it an accurate lathe.
You will learn much when setting up the rails to that accuracy level.

There are not to many guys taking on a large scale scratch built metal working machine. It just becomes unrealistic and to costly to justify at a certain point.
Anyhow, good luck with your build and I'll be watching to see what you come up with.

Steve

[Fixee]

Whoaa...Were you on some good strong narcotics when you wrote that?

... that was written while I was still in hospital. And yes I was on strong narcotics. Your instincts are good.

Doing much better health-wise now, and with no narcotics in my body, let me say that we agree regarding most every point you've made.

Also, let me note that I'm not wealthy.

So let's say that realistically, I'm looking to end up with a lathe for which the accuracy falls between a South Bend 12" Toolroom Lathe, and a Monarch EE. But my goal will be the Monarch because without stretch goals, we don't make progress.

Yeah, it's going to take a while, with much intermediate learning. My estimate is at least 2 years. My first lathe is envisioned to be about 7x18, based on a steel C channel filled with E/C, using C3 (high precision) linear guides and C3 ball screw. I haven't even begun to calculate what precision level I'd need to compare to a EE, especially with the proposed 30" spindle to spindle. But that will come soon enough. Actually, I probably don't want to thing about the costs associated with the higher grade components yet - it might scare me off, so I may sandbag that for a while.

From where I sit, however, it all comes down to figuring out a good headstock/spindle solution. None of the design/build effort is trivial, but this is where I'm finding the least in the way of ready solutions. I have some creative ideas about how to overcome this issue, but want to focus my efforts for now on nearer term steps.

Things will slow down beginning tomorrow, as I start back to work (albeit part-time for now).

Anyhow, welcome aboard and keep your thoughts coming.

Cheers,

Fixee

[hesham morsy]

hi Fixee
small lathe


OmniTurn CNC Lathes Factory Direct!

[S_J_H]

. that was written while I was still in hospital. And yes I was on strong narcotics. Your instincts are good.

lol, been there..
Good to hear your health is better.

Steve

[Fixee]

hi Fixee
small lathe


OmniTurn CNC Lathes Factory Direct!

Hesham,

Help me out. I'm not sure where you're going with this.