Re: Lathe CNC retrofit

Smoke, others,

Be careful. Most lathes are designed to be driven from the front. The
location of the ways 9vee vs. flat), and the saddle and apron
construction are all designed around this assumption (on most lathes).

And Fred is right, there are greater forces acting on lathes than
many assume.

There have been successful cnc lathe conversions using a rear mounted
screw, so it can be done. But be sure you understand the forces
involved and how they relate to one another, and the final results
attainable with the converted machine.

Hope this helps.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., "Smoke" <smoke@t...> wrote:
> Many lathes could easily be altered to CNC by putting in a
detachable lead
> screw in the rear of the lathe. In use as a CNC machine the
standard lead
> screw would be disconnected.
> The standard half nuts would not be used during CNC operation.
>
> Should the individual have reason to return to manual use, it would
be a
> simple matter to disconnect the CNC screw and reconnect the
standard screw.
>
> The rear of the lathe usually has plenty of space for anti backlash
nuts.
>
> I'd use a lead screw for the CNC the same size as the standard lead
screw.
>
> Smoke
>
> > >I've been thinking about CNC'ing my Sharp 13x30, and I'm
wondering
> > >what the max loads are that the leadscrews see during typical
> > >cutting? By the nature of the lathe design, it seems the
majority
> > >of the cutting forces are directed downward against the ways. I
> > >don't remember feeling the same resistance at the handwheels
while
> > >"lathing" as I do on my mill.
> >
> > Carlos, the "work" done by a lathe is usually considerably more
than a
> mill. In a commercial setting it is not uncommon to see a CNC
lathe with
> 20-30 hp and CNC mills with only 10. This is particularly important
if you
> want to drill any holes over about 3/8 inch (which a 13 inch lathe
should be
> very capable of doing)
>
> > Most people have trouble finding a place to put an antibacklash
nut on a
> lathe. They are hard to fit under the apron and crossslide (X
direction).
> >
> > Best Regards, Fred Smith- IMService