Gunner Asch wrote:

On Tue, 17 May 2011 11:10:47 -0500, "Pete C."
wrote:


As Ed stated below, the Japanese techs were using laser devices. The could
map a 6' travel to half a tenth, cumulative, easily. (I'm betting it was
better than that)

Yep, the ball screws for real machines are laser mapped. You can
probably buy your ball screws mapped with a pitch error table included
for an extra charge.

Most ballscrews today..have very very very little error in their entire
length.

I would expect that with the drive for higher and higher accuracy on the
high end stuff, that would trickle down to the lower end stuff as well.