Re: Asian Lathe Conversion

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "mayfieldtm <mayfiet@i...>"
<mayfiet@i...> wrote:

> I'm considering purchasing a 12 x 36" or a 13 x 40" gear head lathe
> from Grizzly or Enco or ???
>
> Tom M.

Tom I own a Griz 1001 12 X 36. It has provided me with several years
of good service. I've used it to turn down ballscrew ends for my CNC
projects and to make custom bushings and shafts. I have looked at
converting it to CNC since I just did my large kneemill. There are
some issues that you should concern yourself with. The lathes come
with nice pretty gear boxes with shifters that allow for defined
feedrates (both carriage and crossfeed). If you replace the standard
feedscrew with a ballscrew, most likely the pitch will be different
and the threading settings will be worthless pretty much negating all
that money you spent on the gearbox. For threading you will have to
have something that will "lock" the rotation of the spindle with a
the steps of the leadscrew. Replacing the leadscrew and mounting a
stepper or servo control (you need encoder feedback for threading) is
no big deal. Getting it all working together is I suspect a bigger
deal. I know you don't want to go used but there is a lot of cheap
iron around that is already CNC. The best deals would be on a good
lathe with a fried controller box but good motors and ballscrews.

Maybe I am obtuse, but I came up with all kinds of reasons to CNC my
mill (cutting circles and odd shapes and concave pockets, etc) but
most of my lathe work is turning down something round and is one-of-a-
kind type stuff so the time to do the CAD work ends up being greater
than just cutting it by hand. I couldn't make a good case (at least
to myself) why I would make the conversion.

One last rock to toss. If you are not an experienced machinist of at
least the home shop varity, then stepping from nothing to a CNC lathe
could be a real challenge.

Regardless of what you decide, do SOMETHING with motion control. It
is a blast!