32i doing something strange

[zman300]

32i control on vertical cnc lathe.

Having a problem withe the z axis motor.
Sometimes when you home the machine it works fine.
Sometimes it hits 250% and alarms with z soft thermal.
I'm told the z axis motor is bad.
No problem, under warranty.

It's doing something they can't explain.
You can turn the handle to move the head up and down.
The head doesn't move but, the display says it's moving.
After turning it back and forth a few times it will alarm.
How can that happen.
They don't have an answer for that yet.

[MysticMonkey]

possibly a faulty brake or power to brake

[CNCZILLA]

You need to look at the load on the Z axis when moving it, this will tell you if there is something mechanically wrong or not. Use your manual pulse wheel and move it slowly while watching the load. If your load starts to increase as you move the axis then you have some bindage or something mechanical is wrong. If your load does not go up and you get an alarm then it is probably electrical, I.E. drive or motor. If you want to determine if it is the motor then you will have to get a little deeper in it. You can block up your Z axis so you can diconnect the belt and seperate the motor from the ballscrew. Then use the pulse wheel again and jog the axis you should see the motor turn. If it turns fine with no loads and no alarms then the problem is not the motor. If you have to do this procedure then when you reconnect your belt you will have to reset your Z Zero. This procedure is of course more time consuming and depending on your machine it could be easy or hard. You are basically trying to isolate the components to determine where the problem is. If it is determined to be electrical then swap the drives and see if the problem moves. This will be the quickest test to do first. I would swap the drives first before trying the mechanical check and see, you may get lucky and have a bad drive and not have to get into the mechanical part. This shouldnt take long and you can eliminate that pretty quickly. However if the machine is under waranty then the Distributor service dept should be handling this.

[fanuc-support.c]

Does this machine have DCS (dual check safety)? I have seen some software conflicts with this that can cause some strange things to happen.

If not your probably looking at a defect servo amp.