[ikke1983]

Hi,

I am having overcurrent faults from time to time on my Z-axis of my milling machine. This is probably the result of bad tuning. For the X and Y axis I tuned the torque loop first, then the velocity/position loop. The problem with the Z-axis, is that it's very heavy and moves down very quickly when the brake is not applied. I have tuned the torque loop with the motor dismounted, and I noticed that the brake is not being applied during torque tuning. How can I properly tune the Z-axis while the motor is mounted? Or is the load of no influence on the torque tuning?

A second thing I noticed, is that when I try to tune the velocity loop of the Z-axis, the target velocity is not a nice and straight up/down slope. But a slope with many "peaks" on it. Instead of raising the speed in a linear way, it goes up and down a few times before it reaches it peak value. The X and Y don't show this behaviour, is it because of bad torque tuning?

Hope someone can help me.
Thanks
Jonathan

[Jmhx2]

Do you have an output that engages the z brake? I set the output to enable the brake during tuning, the servo overcomes the brake and allows me to tune. Another method is disconnecting the power to the zbrake, this should engage it. Then do your tuning. As far as the curve, do you have any storage scopes available? If you can monitor position error while executing a repeatable move ie a circle you use it reduce error after making parameter changes. Providing your setting are somewhat close to begin with.

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[Xerxes]

Few questions to be able provide better answers:
*What type of motor? AC/BCLDC or DC?
*Please send current GDtool settings file here
*Also send tuning graphs as PDF

Anyway tuning torque for Z should be no problem because it doesn't matter whether axis rests on bottom of travel or is held by brake. So the problem probably is something else.