Schaublin 102N to gang tool lathe conversion

[danilom]

As I have a full time working Mechmate cnc router, and a full parts bin, this project is about learning new stuff. Like turning and Mach3 usage on a gang tool lathe.

For this purpose, I dug out 2 Nema34 motors (Jenaer Antriebstechnik GmbH . Stepper Motors), 1.8mH 6Nm and two 2M982 stepper drives (80V 7.8A) for the electronics. And I got 2x 16mm dia, 5mm turn ballscrews.
What is missing are linear rails for which I plan to use Hiwin HGW20CC.

And last but not the least here is the lathe I got, its a Swiss made SCHAUBLIN 102 with 102N gearbox head, w20 collet head and 110mm chuck. Weights about 450kg with cast iron base and has a interesting variator system which will be replaced with VFD.

Plan to bolt the Z rails to the T slot on the side with a long T strip. Will make them a bit shorter than the slot so the rails sits only on the lathe casting. Its easy and will have a very precise mount position to the spindle. It might not be most rigid and I seek some more ideas.

These are the pictures of it. I got some more work on a 3D model and will post it later for review.


T slot insert for mounting rail

[danilom]

Here are some of the renderings of what I am trying to accomplish.

[The Blight]

Looks like it's missing the saddle from the pictures, and your plan to put linear rails on it. Too bad. Schaublin makes solid machines, and if I had a complete one, I would not modify it at all. Other than that, it looks like a good plan. They made it really easy for you with the T-slots.

[danilom]

It was a second operation lathe, so came with a 6 position turret, I plan on selling it. Also removed collet closer handle as I will be making a pneumatic one.
I agree its a very nice and tight machine but it was priced right and seemed easy to modify.

Currently I am trying to squeeze the ballscrew-nut in the middle of rails. It would be easier to put it on the side but I have no idea how will it affect performance.

[The Blight]

That explains it! Then this is the right way to go.

The models I worked on had the screw placed underneath the bed, but that doesn't seem possible on this version. Good luck, and I will be following this one.

[wizard]

It was a second operation lathe, so came with a 6 position turret, I plan on selling it. Also removed collet closer handle as I will be making a pneumatic one.

Are you really sure you want to sell that turret? Beyond that do you have a tail stock to go with it?

I guess the value of the turret depends upon how you expet to use the lathe. If it is mostly for chucking operations and you only expect to use gang tooling on the cross slide the turret can go. I just see you giving up flexibility dropping the turret.

I agree its a very nice and tight machine but it was priced right and seemed easy to modify.

I've never seen one before yet I can see in the pics that it will be an easy transition to CNC.

Currently I am trying to squeeze the ballscrew-nut in the middle of rails. It would be easier to put it on the side but I have no idea how will it affect performance.

The impact of final drive will depend upon the geometry you implement in the saddle. A suitably stiff saddle with good solid bearing support should drive OK. It probably would never be as good as driving from the center of the slide, however lathes have been driven from the side for centuries now.

I suspect your bigger challenge will be the mounting of your linear rails, getting them parallel to remain free of binding will be a bigger challenge. I'd also be concerned about chips collecting on the top sides of the rails.

I don't know what your final intended usage is. However if your intentions are primarily chucking operations with no tail stock or turret you may want to consider locating the lead screw centered on top of the ways. Fix the leadscrew to the saddle and drive the leadscrew from a bearing block towards the right end of the lathe. That would mean a rotating ball nut. This does a couple of things for you, first it centers the leadscrew. Second it keeps the leadscrew out of the heavy chip producing areas.