Re: [CAD_CAM_EDM_DRO] Re: Lathe CNC retrofit

Hi Ballendo:
Are you concerned about carriage racking with this approach?
I would assume that this is an issue on any lathe with an asymmetric bed, ie
one that has a prismatic way in front, and no contact on the sides.
I am assuming therefore that it does not apply to square way machines like
the small Atlas.
I've considered dropping a ballscrew in a drawbar tube directly under the
tailstock, between the ways.
Unclamping the drawtube would function as a "quick-disconnect", allowing the
lathe to be used manually as needed.
Can you see any objections to this basic design.
I had thought to use two manual pulse generators like the Bridgeport EZ
Turn, but I'm finding that you really lose the "feel" of the cutting action
with MPG's, so a quick disconnect is a better option for me.
Cheers

Marcus

From: "ballendo" <ballendo@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Wednesday, January 30, 2002 1:35 AM
Subject: [CAD_CAM_EDM_DRO] 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