On Sat, 10 Sep 2011 17:13:01 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Thanks Lloyd for the info.
Eric
fired this volley in
:

Inaccurate ballscrews aren't
a problem, just loose ballscrews.


I understand that. I'm not using loose ballscrews, I'm just resorting to
C7 precision screws rather than what I'd like to use -- can't afford the
good ones.

My ball nuts, end supports and thrust bearings all support essentially
zero backlash. I'm not using spring-loaded dual nuts, but thread pitch
skewed nuts that have an inherent preload.

The scales come from India, from Electronica Mechatronic Systems Pvt.
Ltd. I'm buying them on a "piggyback" order from DRO Pros in California.
(they get a cut, of course)

Their lead time is about three months, because they only import four
times a year, but they'll make up any scale you want from their stock
parts, and put it on the container. Mine are presently "stolen" from a
DRO using their parts, but I'll replace the DRO scales with the ones that
come in by December.

I mis-typed the precision of the scales. Mine are 1 micron (not micro-
inch) in X and 5 microns in Z. That makes a difference.

LLoyd