Re: [CAD_CAM_EDM_DRO] BALL SCREW INFO

> I priced a screw-kit for it (a "drop-in
> and go" thing, they promised!), and it woulda cost me half what the

machine

> cost!

Jan,
For my Bridgeport Moag retrofit I used custom length Rockford precision
rolled ballscrews on X (42"), Y (16"), and Z (14" on knee). The total
ballscrew cost with preloaded bearings was around $960. I machined the ends
on the X axis to shorten the thread length and match my end mounts. (around
March 2001)
The XY kits with precision rolled ball screws and pre-loaded nuts for
just about any Bridgeport clone (they have a list) ran around $550. The
modified Bridgeport mount bracket was $75. They say it takes around three
hours average to install.
Though I can't recall exactly, the price for 5/8" ballscrew (non
precision, .003 cumulative) and ballnuts were something in the range of $50
per 60" and $20, respectively. The thing I remember is that I could replace
one of my lathe's crosslide screw and bearing for under $100 and still have
a good length of ballscrew left over. Or, I could build a machine using them
and have enough left over to replace the lathe crosslide screws for 'free'.
:) Priorities straight, here.
The people were good to deal with. This was all for use at my business,
but I didn't get the impression that it mattered.

- Keith Rumley


My screws checked out to be +-.0005 every 12". (Non-cumulative, I think. Got
lead charts somewhere around here.)


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