[scecil]

We have a VMC 760/22 with seimens controls.

Recently we have had issues with our spindle acting up. It started while doing tool changes, the spindle would try and perform its orientation but would spin and vibrate, and jump around, looking for home position. Sometimes it would stop at what it thought was home position but would actually be off by 30-40 degrees. This would cause tool change issues obviously.

After replacing bearings in the tool changer, we replaced the encoder for the spindle. The problem was identical. We were told to try a new spindle encoder cable, which we did to no avail. After that we tried a new encoder/cable combination and still have had zero success.

Also, after the spindle is powered on, when commanded to stop it will stop and then has a shake to it. The spindle feedback shows it being under 5-10% load at all times, with or without a tool in it.

Our "regular" technician is out of his office until after the first of the year so we have no where else to turn.

Any help would be appreciated guys.

Thanks

Scott

[kongzai]

I have a machine with same problem as yours, spindle can't stop perfectly / shakes during stop. It happens to be Siemens spindle module (power supply) problem. It is ok after replacing a new power supply module for spindle.

I think your problem with the tool change orientation is caused by the same problem on spindle module. It knows where it supposed to stop but it can't do it perfectly, if you know what i means, :P

[EFI-Unlimited]

My TC-22 w/ DX-32 control did the same thing when I turned the feedback gain up too high.

Brian