The spindle orientation goes awry on occasion. The machine will run a program and the tool changer works fine for a while. At any moment, the orientation goes off about -15 degrees, the carousel comes out to the spindle and the spindle will still grip the tool but the dog ear is not in the slot on the tool, the spindle turns on and the program keeps running as usual. There are no alarms. I turn the machine off and on and the spindle orientation is where it should be. The value has not changed in the parameter. The tool changes normally again for a while.
I figure if the encoder was bad I would get an alarm. I'm thinking the canned cycle for the tool change is not copying over to the RAM completely.
Has anyone seen anything like this? Any suggestions?