Upgrade Issues. Drive Faults and Jerky behavior-RESOLVED
Posted: Sat Apr 04, 2020 6:49 pm
Update:
I believe my issues with noise have been resolved. The fix turned out to be grounding the VFD cable shield at BOTH ends of the cable. At the VFD and at the Motor. This is contrary to conventional shield grounding but is necessary for this type of application according to Beldin Cable.
Photos of the Control Box and Mechanicals: https://photos.app.goo.gl/
CNCPC: I5-2400 @ 3.10GHz , 8Gb Ram, NVIDIA GeForce GTX 1050 Ti, ASUS VT229H 21.5" Touchscreen Monitor, Centroid Wireless MPG
Centroid Acorn System Report: https://www.dropbox.com/s/xhyx9ggbpynig ... 4.zip?dl=0
I have been upgrading my ShopSabre 23 to Acorn and ClearPath servos.
I currently have 2 problems.
The first is noise interference from the spindle.
Here is what I have done to try and mitigate that:
(1) Added 2.2K resistors between Step/Dir and +24V
(2) Added an EMI filter to the line inputs of the VFD
(3) Replaced power cable from VFD to Spindle with a Shielded 16AWG Cable grounding the drain wire at the VFD only
(4) Reduced the step pulse frequency to 100K
The new cable made the biggest improvement but did not eliminate the problem completely.
I will get random DRIVE FAULTS only when the spindle is on. I can aircut a program with the spindle off without having a drive fault. The faults always occur on the Z axis motor. As far as I can tell…
The Motor Setup Program from Clearpath warns of a shut down on that motor due to either a short, noise or step pulse width too small. Only happens with spindle running.
The only thing I have’t tried yet is to reduce the length of the Z-Axis Data Cable. I left it longer than necesarry just in case… It is probably at least 15ft. long
My VFD is not in my control box. It is mounted to the wall away from the control box. Only the power cable runs through my cable chain to the motor.
All the DATA and POWER cables for the motors are purchased directly from Teknic. The data cables pass through the control box directly and are wired directly to the inputs on ACORN according to Centroid schematics.
I have run out of things to try to resolve this problem…
The second issue is also bad. There is terrible Jitter/Jerkiness on the Y-Axis.
I may see a slight amount on X-Axis but it does not compare to what is visible on the Y-Axis
I am running the largest/strongest Nema 23 motors that Clearpath makes. They are replacing the 286 oz/in Nema 23 Steppers that came with the machine. They are direct drive. I saw none of this jerkiness with the steppers. Even on a simple straight line Y-Axis move the jerkiness is evident.
Here is what I have done to try and identify the problem:
(1) in an attempt to localize the problem I swapped the X and Y Motors and ran the AutoTune function again. The problem persists and did not follow the motor to the X axis. Although I do not fully understand the Scope feature on the Clearpath MSP software it showed incredible erratic position errors for that axis compared to the others. I am beginning to suspect some mechanical issue but I can not be sure. It may also be the Auto tune settings. Whatever it is it is unusable. This may require a call to Tecknic’s engineers.
Video of the Jerkiness on Y-Axis:
I also was having connection issues between the CNCPC and Acorn. I had to remove the RJ45 Connector on the control box and run the wire directly through the wall of the control box to connect it directly to the Acorn…..One issue after another
I am ready to slit my wrists………
If I can’t find solutions I may be forced to undo my $3000 upgrade and return to lackluster performance in order to get the machine back on line. I have spent a lot of time and money on this and it’s killing me……
I believe my issues with noise have been resolved. The fix turned out to be grounding the VFD cable shield at BOTH ends of the cable. At the VFD and at the Motor. This is contrary to conventional shield grounding but is necessary for this type of application according to Beldin Cable.
Photos of the Control Box and Mechanicals: https://photos.app.goo.gl/
CNCPC: I5-2400 @ 3.10GHz , 8Gb Ram, NVIDIA GeForce GTX 1050 Ti, ASUS VT229H 21.5" Touchscreen Monitor, Centroid Wireless MPG
Centroid Acorn System Report: https://www.dropbox.com/s/xhyx9ggbpynig ... 4.zip?dl=0
I have been upgrading my ShopSabre 23 to Acorn and ClearPath servos.
I currently have 2 problems.
The first is noise interference from the spindle.
Here is what I have done to try and mitigate that:
(1) Added 2.2K resistors between Step/Dir and +24V
(2) Added an EMI filter to the line inputs of the VFD
(3) Replaced power cable from VFD to Spindle with a Shielded 16AWG Cable grounding the drain wire at the VFD only
(4) Reduced the step pulse frequency to 100K
The new cable made the biggest improvement but did not eliminate the problem completely.
I will get random DRIVE FAULTS only when the spindle is on. I can aircut a program with the spindle off without having a drive fault. The faults always occur on the Z axis motor. As far as I can tell…
The Motor Setup Program from Clearpath warns of a shut down on that motor due to either a short, noise or step pulse width too small. Only happens with spindle running.
The only thing I have’t tried yet is to reduce the length of the Z-Axis Data Cable. I left it longer than necesarry just in case… It is probably at least 15ft. long
My VFD is not in my control box. It is mounted to the wall away from the control box. Only the power cable runs through my cable chain to the motor.
All the DATA and POWER cables for the motors are purchased directly from Teknic. The data cables pass through the control box directly and are wired directly to the inputs on ACORN according to Centroid schematics.
I have run out of things to try to resolve this problem…
The second issue is also bad. There is terrible Jitter/Jerkiness on the Y-Axis.
I may see a slight amount on X-Axis but it does not compare to what is visible on the Y-Axis
I am running the largest/strongest Nema 23 motors that Clearpath makes. They are replacing the 286 oz/in Nema 23 Steppers that came with the machine. They are direct drive. I saw none of this jerkiness with the steppers. Even on a simple straight line Y-Axis move the jerkiness is evident.
Here is what I have done to try and identify the problem:
(1) in an attempt to localize the problem I swapped the X and Y Motors and ran the AutoTune function again. The problem persists and did not follow the motor to the X axis. Although I do not fully understand the Scope feature on the Clearpath MSP software it showed incredible erratic position errors for that axis compared to the others. I am beginning to suspect some mechanical issue but I can not be sure. It may also be the Auto tune settings. Whatever it is it is unusable. This may require a call to Tecknic’s engineers.
Video of the Jerkiness on Y-Axis:
I also was having connection issues between the CNCPC and Acorn. I had to remove the RJ45 Connector on the control box and run the wire directly through the wall of the control box to connect it directly to the Acorn…..One issue after another
I am ready to slit my wrists………
If I can’t find solutions I may be forced to undo my $3000 upgrade and return to lackluster performance in order to get the machine back on line. I have spent a lot of time and money on this and it’s killing me……