Originally Posted by
CNCRebuilder
This sure sounds to me like a feed back issue. + - .004" this amount is probably the following error in the parameter. Then it running away while your on the wheel.
sure sounds like the feed back is gone. What are the alarms? The brake may be inside the motor, A quick way to tell is remove the cannon plug for the motor supply power,
Look at the pins should be 4 large pins (3 power one ground) if there are additional pins there could be a brake. I will check my 18I book and I believe i have the drawings for this machine as well at the shop. I do believe that most sub spindles do have a brake. Do you have a scope to check the encoder? I made a jumper cable that I install and hook my scope to check the 3 signals and the marker pulse. If you want a picture of the cable let me know.