DIY / Hybrid lathe build

[David Morrow]

I really didn't need another lathe. I already had three. But, I did want a small lathe that I didn't have to stand up to use. I have a Sherline and it's just fine but I wanted something else with a bit more mass and a few other improvements. ( Improvements are in the eye of the beholder in this case.) I wanted the ways to be out of the path of swarf. I wanted a more accurate way without messing about with gibs. Zero backlash lead screws would be nice. I came up with a design in my head. It might not make financial sense to build your own lathe and, as long as costs were reasonable, I thought it would be a fun project. Initially, I had planned to design and build the headstock and tailstock, and source the motor to suit. With my Sherline lathe sitting on the bench beside me, I decided to just strip many of the needed part from that machine. If the project doesn't turn out, I'll just put the Sherline parts back together.

This is what I have completed so far :
The base is a slab of 12" x 24" aluminum that I resurfaced, milled and drilled on my CNC router.

You can see that in place of a conventional lathe way, I mounted a pair of linear rails and slides down below, out of the stream of falling chips and coolant.

I left the original handwheel on the tailstock but the tailstock will run along the Z axis by a handwheel mounted at the end next to the handwheel for the cross slide.

I don't have the lead screws yet but have ordered a set of zero backlash screws and nuts from Haydon Kerk. I've used their products on my two CNC routers and a small benchtop CNC mill and they are great.

I don't like the clearance of the handwheel for the cross slide so may raise everything up an inch later, once I get it operational.

There's still a bit of work to do but it's getting there.

 

[Wizard69]

Hey Dave;

Its been awhile since I have logged in so I've missed this post. It looks like you have started one interesting venture here, please follow up with operational results.

Frankly I'd fear swarf plugging up that channel cut into the tooling plate. Even so love to hear if the result is better or worse than a stock Sherline.

As for cost, don't worry about it, the idea here is to have some fun and explore new ideas. Besides it is hard to compare costs when you deviate from the established designs. A couple of years back one of the hobby magazines ran an article on a stepper driven lathe, I thought it was cool that somebody actually pursued and idea like that. I might even take it upon myself to do something ( a mill maybe) if the planets even align correctly.

 

[David Morrow]

My lead screws just arrived so I have some more work to do now. With those machined and installed, I will be able to fire it up and take it for a test drive. Then I'll be able to see what works, what doesn't, what I like and what I don't. More refinements will undoubtedly follow.

 

[deeferdog]

Nice work Dave, watching with interest. Cheers, Peter

 

[David Morrow]

Frankly I'd fear swarf plugging up that channel cut into the tooling plate. Even so love to hear if the result is better or worse than a stock Sherline.

The channel down the center goes right down to the bench top so it's a proverbial bottomless pit. And don't forget that with this being a Sherline based machine, it won't be capable of producing the sort of chip volume that would ever cause a problem.

 

[Metalsmith]

My lead screws just arrived so I have some more work to do now. With those machined and installed, I will be able to fire it up and take it for a test drive. Then I'll be able to see what works, what doesn't, what I like and what I don't. More refinements will undoubtedly follow.

I also run a Sherline.
I think you've found the solution to several problems that I think need to be addressed.
It appears that you have done just that, good job.
Please keep us posted on your progress.
Bj

 

[jdurnya]

Pretty cool !! im wondering how rigid that is going to turn out.. i would have put the linear rails on top with way covers to reduce the distance to the cutting tool.. but i cant wait to see this in action and see your results !

 

[JimDobson]

You've put some hours into this. Look great.

 

[MrMetric]

Its an interesting idea and experimenting is what keeps us all young at heart and mind.... I do wonder the same thing as jdurnya though. The downside to having the rails below is that you've got an awfully tall structure for the tailstock and carriage. Any slop, or flexing/rocking, gets magnified as a result and could be problematic.

There is one other ergonomic consideration too. The hand wheel on the cross slide is pretty close to the plate. It think that would frustrate me because I'm pretty sure I couldn't even put my fingers between the gap between the bottom of the wheel and the bed (for lack of a better term).

Hats off to you for trying something different. I love seeing innovation, and I look forward to future posts on your learnings.