[extanker59]

Happened yesterday. Our very reliable 2011 VM2 threw a tool in middle of the program for the first time ever. Nothing damaged, not even the tool thrown. Only alarm was 626 "Tool Pocket Slide Error".
Not overly concerned about a thrown tool after 4+ years on that machine. Have seen them before in a VF2-SS and in a Matsuura RA-1F.

It's back up and making parts. We recovered and then shut it down all the way and restarted.

Here's what I've never seen: After the bang of the thrown tool, the next tool was in the spindle and it was trying to max out the spindle RPM. Neither the thrown tool nor the current tool was commanded to go anywhere near 12000 RPM. 1222 for the previous tool and 4583 for the current tool.
Has anyone else seen this? Has me concerned.

[nicknackks]

While I'm not sure if this is one of them, I do know that there have been some software issues with the tool changer that can cause 625, 626, 628, or 858 alarms. What version of software does your machine currently have? The only other thing I would suspect is that there may be an issue with the spindle encoder or encoder belt. This can cause issues with spindle orientation (may have caused the tool to be thrown) and can also make the actual speed displayed vary from the commanded speed. It is fairly simple to removed the head cover and check the condition and tension of the encoder belt and that is what I would do if I was in your position.

[nicknackks]

It looks like your software version is not listed, however, that doesn't mean a software glitch is not a possibility. As long as it doesn't happen again, I wouldn't worry to much. If it does, check out the spindle encoder belt and let me know. Otherwise, happy chip making!

[extanker59]

Thanks again. I'll keep this post updated. Hopefully it will not be updated because that will mean it didn't happen again.