re:Making leadscrews more accurate

Les W wrote:

>A ballscrew or other leadscrew has pitch errors that can accumulate
>to large values over a distance of feet.<s>It sometimes is periodic
>and cancels over length but often does not.
>So I chose a simple robust mechanical approach. One of the nuts is
>in a thrust bearing that allows it to rotate about 45 degrees as it
>moves. A ball bearing cam follower is on an arm attached to the ball
>nut as well. This arm engages a strip of steel mounted parallel to
>the screw travel that acts as a cam. It is held by a spring strong
>enough that it will always stay engaged.
>So as the nut moves along it can rotate slightly adding and
>subtracting small amounts to the travel. The rotation depends on the
>shape of the cam strip.<snip>
>Make sense? descriptions are harder without pictures!

Les,

This is great stuff! Very well explained, IMO. I could see this
easily being used with single screws as well! Of course, if the
software has compensation, I'd use that, but...

THANK YOU!

Ballendo