[alphaorange]

Lots of sharp guys here so I figured I'd ask...what is the procedure for replacing the X ball screw on a VMC 40? I've got some mechanical noise that that is related to the rotation of the screw. Its worse going in the + direction. It can be felt in the table as well. I also have finish issues when milling angles but thought I would get the mechanical straightened out before I adjusted the clock and gain. We are now checking the bearings on the ends and will replace them as needed.

The coupler shows some wear and will be replaced. It almost feels like there are bad spots on the balls as it sometimes is worse than others. Does anyone have a source for ball screws (part numbers would be great).

Lastly, if anyone can tell me the procedure for ball screw replacement, I would be very appreciative. Thanks in advance


John

[dunnitagain]

What year is your machine? Some of the old machines oiled the x ballscrew,by the way oil that bypassed through the turcite on the back right of the table. Consequently the ballscrew ran dry or not enough oil to flush out chips.

[IN2GLAMISGIRL]

Check the thrust bearing first. This is a common failure point and will usually
make more noise in one direction.

[alphaorange]

Thrust bearings seemed ok and the screw looks to be in nice shape. Ater speaking with Jeremy at Superior Ball Screw, I have a suspicion the ball return in the nut is not working correctly. I have sent it out for evaluation as I could "feel" something at random times when turning the nut, albeit ever so slight. Plenty of oil. Machine is a 1994 VMC40.

I am replacing the bearings, seals, and whatever the ball screw requires. I'll likely need more help as I continue to bring this old one back to snuff. I'll let you know as it happens. Thanks

[alphaorange]

Update...had the ball screw rebuilt and installed with new bearings. Noise is gone but now the servo motor sounds like a hammer when you jog (or run) from +x to -x but only on the direction change...just a "bang" and then smooth. Table runs smoothly and is not too tight. Coupler is new and motor is aligned to the screw within .002 TIR. Ideas before I disassemble the servo motor?