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Re: Axis jumping when moving

Posted: Wed Jan 03, 2018 9:19 pm
by toolmaker101
Chased down the wires. One goes to the Qudra drive and the other goes to the square black thing the print say it is a 24V supply.
I attached some pitchers to help.

I am not sure what turns it on or off??? Could it be something that is not programed right in the plc?

Re: Axis jumping when moving

Posted: Wed Jan 03, 2018 9:21 pm
by toolmaker101
the print

Re: Axis jumping when moving

Posted: Thu Jan 04, 2018 12:15 am
by cncsnw
Because you have a Revolution machine, but a Centroid print, you have to take what you find on the print with a grain of salt. Revolution designed their own cabinet wiring, different from what the Centroid factory did.

The square black device is a bridge rectifier. It is making sort-of-DC out of an AC supply (I say sort of, because there is no smoothing capacitor). One side of the DC goes directly from the bridge rectifier to the motor brake. The other side goes through a Z Brake relay on the QUADDRV1. The drive should close that relay to release the brake, any time the axis is enabled. The PLC is not involved.

If the rectifier has failed, or the relay on the drive is burnt, then the motor brake may not be releasing when it should. That could cause stalls, which would typically be reported as "410 Z axis(3) position error" or "411 Z axis(3) full power without motion" or "409 Z axis(3) lag".

If no stall message appears, then it is unlikely you have an axis stall occurring.

In an axis stops moving, without any stall occurring, then it is usually because the command to make it move has been removed. If you are trying to use a jog button to move the axis, and it moves a bit and then stops, it may be that the jog button itself is balky (though I assume you have a brand new jog pendant). Also, a tripped limit switch on any axis will cause any other axis to stop jogging. Therefore if you have intermittent limit switch problems, that could also be related.

Finally -- though it is unlikely given the PID gains you have in place -- it is possible you have PID gain values that are not stable given your particular drive and motors. Try changing, just on the Z axis, to Kp = 0.6, Ki = 0.002, Kd = 1.2 and see if that makes any difference. It is doesn't help, change them back and continue to pursue the encoder.

Re: Axis jumping when moving

Posted: Thu Jan 04, 2018 12:26 am
by cncsnw
On a related note, you have the "full power without motion" stall condition defeated.

You should change Machine Parameter 62 from a value of 115 to a value of 90.

Re: Axis jumping when moving

Posted: Thu Jan 04, 2018 12:46 pm
by toolmaker101
Thank you!!!

Changed parameter 62 to 90 this did not fix it but left it at 90

Then Z axis, to Kp = 0.6, Ki = 0.002, Kd = 1.2 this did not fix it ether. so I changed it back to what it was.

I then installed a new encoder that did not fix it.

Any other suggestions? please and thank you.

Re: Axis jumping when moving

Posted: Thu Jan 04, 2018 8:10 pm
by toolmaker101
New up date after checking the voltage for the brake on the Z axis it has 115VDC and the motor calls for 90VDC.
What I do not understand is there is the same voltage going to it if the weather I try to move the Z or not.
If i disconnect one of the wires there is a click noise and if I try to move the Z axis it is locked up like the brake is on.
Thank you!

Re: Axis jumping when moving

Posted: Sat Jan 06, 2018 1:55 pm
by toolmaker101
Had great progress with this yesterday, Scott did a Team viewer session and tuned all 3 motors. This has fixed the issue of my Z axis jumping :D :D :D :D

Thank You all for the help!!!
Tome to make some chips.