I'm wondering what hardware software combination to use. the original ELS project seems a bit long in the tooth. There are 3 or 4 on github and a Russian lead screw design.
I "need" a 1/2"-12 left hand thread. My lathe has no reverse so i'm thinking it would be just about as hard to do the electronic lead screw as it would be to add the reverse. I'd also need to make a thread dial. Changing the gear on that thing set is no picnic either.
It is really a very short distance from ELS to full on CNC and the CNC may actually be easier and cheaper to accomplish due to the availability of various kits. The total cost could run from <$500 to as much as you want to spend.
If you want to keep full manual capability then it gets a bit more complicated, but not a show stopper. The only addition required is backlash control on the carriage, and a couple of relays or switches to disconnect the stepper motors from the drives. I was going to do this to my lathe but then I bought a CNC lathe and dropped that project.
Jim, do you ever find yourself wanting to have a manual lathe again? I suppose the only thing stopping me is that having to do CAM for everything is a barrier to getting stuff done sometimes. I have a cnc mill and a manual mill. I kinda don't want to convert the manual mill since it is convenient and quicker for many things.
I still have my manual lathe, I didn't sell it when I bought the CNC. I would really miss it if I didn't have it. They are really 2 completely different machines with different purposes. I have thought about adding CNC capability to the manual lathe, but keeping full manual operation with an instant change over. I have all of the parts on the shelf to do it, but really have not had a need to do it.
My knee mill is almost instantly convertible between full manual, 2, 3, or 4 axis CNC. Many times I use a combination of operating modes on a single job.
There's a nice ELS from Germany that they call an Electronic Lead Screw - Stefan Gotteseinter did a review of it on his youtube channel. They will have a complete English manual available early this year. It leaves manual operation untouched and is DIY for the home machinist.