[eman5oh]

Does anyone know how to adjust the backlash on a ez-trak mill? I would guess that the ballnut can be adjusted. If this true, any specs for torque or preload and how to measure. Thanks.

[machintek]

I have never fooled around with the ball nut. Anytime it is too loose, the ballscrew gets regound and bigger balls are loaded. I installed a few machines at a place called National Precision in Franklin, TN. That is his business. He rebuilds ball screws.

To adjust backlash, I increase the value in the machine by .002 inches. I then machine a circle in aluminum with a spring cut. Now sweep the circle with a dial indicator. The steps you measure are how much it is overcomped. Subtract this value from what is in the machine. If it varies at 3 and 9 oclock, then your X ball screw is worn unevenly. You may want to average the compensation. Ditto for the Y.

To get to the backlash value, at the main screen, press the * key, the key word is 11235 followed by enter twice. Do not forget to save. If a ball screw is replaced or reground, the existing pitch error comp values are worthless.

George

[NC Cams]

Don't forget to check for looseness and/or wear in the ball screw support bearings.

An overly tightened or improperly adjusted gib (did it myself) can also cause "backlash" problems

Our of tune servo amps will further contribute to non linear servo performance.