Re: ballscrews...

> From: ptengin@...
> I have a 14.5" South Bend. Like your machine, the nut is tired. Rather

than

> replace the existing nut and screw, I was considering hanging the ballscrew

> and nut outside of the carraige. My unit has a taper attachment so I can
> disconnect the cross feed screw from the cross slide. Now, if I can arrange

a

> method of connecting and disconnecting the ballscrew, I can use the

original

> screw for manual use and the ballscrew for CNC operation......

Chris & Pete,

I've got a 14-1/2" SB as well, also with taper attachment. My nut is worn,
and my threads are a little "pointy" in the middle of the screw. I was hoping
to put a ballscrew in the same place as the old leadscrew. I made a drawing
of the screw at one time and I'll try to dig it out, and post it somewhere.
My machine is probably going to stay manual as I can't figure a good way to
mount motors without butchering the lathe pretty bad. I don't have enough
room behind the lathe for an outboard screw.

I wonder if math functions such as the ones Chris has on his page that
describe the curves of a horn bell could be added to RS-274, rather than
approximating them with short line segments and single radius arcs.

Matt