89 vmc 40 refurb. Developed a squeak/squeal on the x axis in feed moves. It is on the motor side. It is cyclical and seems to be in sync with the rotation of the ball screw. On slow feed moves it sounds like a porpoise.

Any suggestions? Seals?

...vibration if you put your hand on the motor housing? Then it might need a axis drive adjustment. Seal? I not sure, but most likely not. Thrust bearing maybe... Turcite ways dry?.. maybe... check for lubrication. Way covers? There is a seal on the ball screw nut (I think) lubrication again...? If it moves on that axis check it. It has to be one of them.:confused:
Steve

I had I bad squeal on the z axis of my vmc15. It was intermittent and pretty loud. I turned out to be the encoder. It was hard to believe but the little encoder was responsible for all that noise.

We have a 4020 here that has what I believe is the same problem as did Edster. The Z axis sometimes screams like you just stepped on a cat's tail. I
think it is coming from the resolver mounted on the Z axis motor. We run the
machine at 50% rapids to lessen the frequency of this happening but the tool
changes are still at 100% and the squeal usually occurs during the rapid acceleration as the head moves down to pick up the new tool. Seems like the bearings in the resolver cannot get up to speed quickly enough. Got to change it and see if the noise goes away or maybe if we could slow the acceleration a bit on Z that may help.
Thanks,
Gary

http://www.youtube.com/watch?v=W9OOT7QCWBM ? :D

We have a 4020 here that has what I believe is the same problem as did Edster. The Z axis sometimes screams like you just stepped on a cat's tail. I
think it is coming from the resolver mounted on the Z axis motor. We run the
machine at 50% rapids to lessen the frequency of this happening but the tool
changes are still at 100% and the squeal usually occurs during the rapid acceleration as the head moves down to pick up the new tool. Seems like the bearings in the resolver cannot get up to speed quickly enough. Got to change it and see if the noise goes away or maybe if we could slow the acceleration a bit on Z that may help.
Thanks,
Gary

Running at 50% was my fix for a few years. We were getting the squeal during toolchange too. If it was at 100% it would squeal anywhere along the travel. I had a tech come by to fix something else and I told him about the problem. He had me jog it back and forth as he hit the motor with his hand. The motor started squealing after he hit it. He said it was probably the encoder so I had him swap the motor out. No more problem and we can run the machine at it's blistering 400 ipm rapids :D

carbidecraters, that motor sounds like sh*t. Ours wasn't that bad, just an intermittent squeal. It sounds like that servo has major problems.

Check the brushes it worked for us.