Re: [CAD_CAM_EDM_DRO] Bridgeport mill ballscrew conversion

john_glynn57 wrote:

>Has anyone upgraded an old Bridgeport milling machine with a leadscrew
>to a ballscrew drive and if so what strategy did you use.
>
>

I pulled out the whole original system, including the "yoke" that the bronze
nuts slide into, and measured it very carefully with a surface plate and a
vernier height gauge. I then made a new yoke to accept my square ballnuts.
It did not fit well, and I had to add shims here and there to line up
the ballscrew!
So, I can't reccomend that approach unless you are a master tool and die
maker,
and can do the measuring better than I obviously did. Now, I think I'd make
some sleeves that fit into the existing yoke and have a flat surface to
accept the
nuts. On the other hand, my replacement yoke has more meat in it, and is
probably more rigid than the original part.

I had some axis drives out of a PC board drilling machine, and adapted those
to the Bridgeport as best I could. They had NSK high-precision ground
ballscrews,
which was why I used them.

Jon