I have a laser cutter with a ballscrew that is approximately 1.250 inch diameter and 12 foot long. It is time for me to have the unit reconditioned and I was thinking of taking it out of the machine and reinstalling it myself. Is there any special way to approach this and are there pitfalls to be avoided?
Long, small diameter ballscrews are notoriously difficult to install correctly. Contrary to common belief, ballscrews are not perfectly straight and long screws are the worst offenders. To work around this problem it is necessary to install the unit in a predetermined order. If the thrust and support brackets are left in position (this may not always be possible) when the ballscrew is removed from the machine, it makes the task a little easier.
When installing the reconditioned ball screw, first assemble in the thrust and support brackets and make all final adjustments to the bearings. With the ball nut all the way to the end that will allow for tightening of the securing bolts, move the slide until it comes gently into contact with ball nut flange face. Snug the bolts down alternately until the flange is locked down. It is important to move the slide it's full travel, turning the ball screw by hand and noting any perceived tightness. Only when it is confirmed that the ball screw is installed correctly should the servo motor be attached.