Hello everyone, this is my first post and visit to this site. Looks like a great resource with lots of valuable data.

I have a Bridgeport VMC 3020, with a Fanuc 21i controller. The machine is a 2002 vintage. We are experiencing a strange problem. As a job is cutting the table will suddenly skip... the z axis will rise and all motion except for the spindle will stop. The table will also skip with the machine sitting idle with no program loaded.
This has been going on for a while now. We have to shut the machine down and restart it. Sometimes this works and other times we have to leave the machine sit overnight and when we start the machine in the morning we may get a few hours out of it before this happens again.
We had a pair of techs in to look at it in June and after 2 days of messing around the machine stopped skipping, but they really did nothing concrete that solved the problem.
Anyone have any ideas or a similar experience?

Thanks

Don