Has anyone used condition monitoring to check ballscrews on machines? If so, what was your method?

I have made diagnostic measurements with both vibration and ultrasound. The difficulty is monitoring over the full stroke which generally requires a long time record analysis. The recirculating balls are similar to regular ball bearings, so you are trying to detect excessive friction (poor lube), looseness and mechanical faults. The ballscrew installation will dictate accessibility for sensor placement, cycle duration, and background vibrations/ultrasound.

Walt
w_f_strong [at] msn [dot] com

One problem is that in a NC machine that do the same procedure most of the time that used part of the travel get worn and is then tightened when getting to lose so when you run the full travel it get stuck. One major problem is the low speed and as Walt say, how to access. Olov

Renshaw (and others) makes a ballbar system that is performance check for machine tools. A short CNC program is needed to move the spindle in a circle. The hardware is setup on the machine, the CNC program is started and a LVDT measures the radius of the circle. The software analyzes the data and displays the positioning error related to each fault characteristics (squareness, waybearing looseness, backlash, straightness, and more).

Check their web site
http://www.renishaw.com/client/product/UKEnglish/PRD-156.shtml