[nmorong]

Hi,

I am having another issue with my 1995 partner 1 series H mill. I'm hoping someone here has seen this before and has some insight.

I am having an issue with the Z axis over traveling, in the downward direction only. It is an intermittent issue, occurring about 1 in 3 times on some days, while not reproducible at all on others. I had noticed it sounding unhappy at the end of downward rapid motions while cutting a part, and the next tool change it slammed down onto the tool changer and alarmed out. I haven't tried a tool change since, but a G32 (rapid to tool change position) from the positive Z limit is the most reliable way to reproduce the issue. The picture shows how far it overtravels relative to the tool changer before stopping with an error 409. The tool change height is set by parameter, I don't believe there is a switch at tool change height to get sticky. Please correct me if I'm wrong about this. It often works correctly several times in a row, and then overtravels, so I don't suspect a problem with where the Z axis is homing. It seems more likely to malfunction on hot days.

I have tested the 24V power supply, it appears to be working properly. I am running on a 25HP RPC, which has been working without issue for months. My only hypothesis at the moment is a power issue, but I'm a little skeptical that it would only show issues now. I would appreciate any suggestions for things to check.

-Nate

[nmorong]

Also, I have custom servo motors ac servos with resolvers, so this isn't an encoder or DC motor issue.

[sportybob]

Not sure if you are describing a axis runaway or a positioning problem.

Give me a call to discuss further.
952-288-6340
Sportybob

[nmorong]

Sorry, I never realized anyone had replied here until after I resolved the issue. It was a power issue, my line voltage was well over 240V and my generated leg voltage was sometimes getting as high as 268V. Presumably it was never an issue in the winter because I was using electric heaters and it was keeping the voltage just low enough to not cause a problem. After installing a buck transformer it hasn't done it again in hundreds (probably thousands) of tool changes.

-Nate