Bridgeport 'Boss' CNC - Quill jammed 'up'

[dansawyer]

The Mill is a Bridgeport middle to late Boss CNC. The control s/w is Linux CNC. I was operating the machine manually and mishit the page up key. The result was the quill moved to the top and is now stuck. Is there a way to free this without disassembling the entire head?
I purchased the mill with the head disassembled so I have experience working down from the top. Fun as that was, I would like to avoid it if at all possible.
Thanks in advance for any tips.

 

[derf]

Sounds like it got past the upper limit switch. You will have to remove the access plate in the front to get to the stop and the switch. I would try to back it off first by rotating the Z axis servo motor. You will need to do this with the servos off. If it doesn't move manually, you'll have to get serious and remove the access plate to see what's jammed.

 

[dansawyer]

Thank you. Yes, the limit switch did not work, I will have to check that circuit out.
I took the front limit switch cover off. There was nothing visible there. There is an additional plate assembly behind the limit switch mechanism. I have not taken that off.
Looking down from the top at the stepper motor is down clockwise or counter clockwise? Or to move the quill down does the cog belt move in from the front or the rear?
To confirm looking down from the top clockwise would move the rear of the belt in .
Sorry to be repetitive, but the terms are relative; not like a sailboat with port and starboard.

 

[dansawyer]

Quick followup: Does anyone have access to the parts manual for the Boss mills? The quill mechanism is enough different that the standard parts list is incomplete.