We are running a Bridgeport 320H with Fanuc OM-Model A control.
During automatic tool changes the machine alarms out with Y+ OVERTRAVEL (Alarm No. 2014) or SPINDLE ORIENTATION (Alarm No. 2013), sometimes both (i.e. we clear the one, usually Y+ OVERTRAVEL, and the other pops up right away). Additionally, we also occasionally get a VRDY alarm as well as a 4 AXIS DETECT alarm (Alarm Nos. 401 and 444?).

We have changed the spindle orientation board, the limit switches, the encoder, even the program and in-position limits. Nothing has had a lasting solution. In the past, we have changed one of these items and the machine has worked for a few weeks, only to eventually regress back to alarm out every single time. We have experienced the alarm before the spindle even gets to the tool change position as well as after it has changed tools and is returning to the reference point.

What could the problem be?

These were not very popular machines, and my experience is limited to the three I installed. Two had the 6MB control and the last one the 0. These were actually made by YASUDA for Bridgeport. The first 2 required a lot of attention, including replaceing the B axis bearing, brakes, and motor. The pallet changer motor was also replaced. The newer machine seemed to have a lot of the bugs worked out. I commend you on the encoder change. It is not easy to get to those parts.
May I suggest that you carefully watch the spindle as it proceeds up into the tool holder. One of the things that would drive us nuts is that as the tool entered the fingers, it had a tendency to rotate the spindle. This was corrected by adjusting as best as possible the position of the tool holder fingers so they rubbed the same amount. It is not easy.
Is it possible that if you do lose your orient, then it faults and it comes out of the tool change subroutine and gives the Y axis fault. I remember that under "normal" conditions, the Y would not go that high and the tool change macro tricked the control into allowing the Y axis to go there.

George

The binary system on that machine run in sequence with the bellville spring which mean that the orientation of the spindle proxy light must orient intime with the z axis home position one or both is out of location.
First check the sprindle proxy to the I.O. output then if you havent already adjusted the z axis home position dont!!! the position should be good. it just meens the collar for the spindle orentation is off alittle.
I know this is kind long winded but sounds like youve adjusted alot already.

George,

We did notice some of the thongs rubbing the tool, but when we tried it with no tool (we did a tool change from an empty spindle to an empty magazine position) we had the same error -- it alarmed out on the way up to the tool change position. Any ideas?

Thanks,
Chris