Axis motion after electronics moved to new enclosure

[SMCNC]

DRIVE-2M542-Manual.pdf

2M542 Stepper Driver Manual

(216.09 KiB) Downloaded 3 times

I built a CNC Router and used a PC case as a temporary electronics enclosure. The machine has run without issue for the last year. The time came to upgrade the enclosure which meant carefully removing and photographically documenting wires and the order they screw into the plugs. Some new wiring harnesses were made but they are a duplicate (except for length) of the original wiring. Everything went well except one issue.

The machine has a Left Y axes and a Right Y axes that are paired. When I push Y- on the VCP, the right and left Y axis moves in the correct direction (Y-) together. When I push Y+ on the VCP, the right axis moves in the correct direction (Y+) but the left moves in the Y- direction. The X and Z axis work as expected as does the spindle.

I've been over the wiring several times and found no obvious problems and nothing varied from the pictures.
Swapping stepper drivers didn't fix the problem.
The DIP switches on the stepper drivers are in the correct position.
I've updated to the newest CNC12 but that didn't work.
I've tried inverting the axis but it still moved on direction regardless of Y+ or Y- input.

No matter what I do, the Left Y axis only moves one direction regardless of input. Any help is greatly appreciated.

[cnckeith]

hello.
any axis motor moving in only one direction is indication of the direction signal not making it to the drive.
since you swapped stepper drives and the issue stayed on that axis, check again the wiring of that axis.

[SMCNC]

Thanks for getting back so quickly. The process of elimination leads me to think it is the signal wire as well. I tried a few things.

The step, direction, and enable wires have continuity as measured from the terminal screw on the Acorn board to the terminal screw on the Left Y stepper driver.

I swapped the X and Left Y stepper drivers again, inspected the connectors for corrosion and debris, and gave the wires the tug test at the plug. There was no change in the problem and no debris was found in the connectors.

The wires in the Left Y plug appear to be in the same order as the other plugs.

I added a couple of pictures to the original post for context. The machine is a standard PilotPro 26-42 that I converted to use an Acorn board running CNC12. The stepper driver is a 2M542.

[Houseman303]

The machine has a Left Y axes and a Right Y axes that are paired. When I push Y- on the VCP, the right and left Y axis moves in the correct direction (Y-) together. When I push Y+ on the VCP, the right axis moves in the correct direction (Y+) but the left moves in the Y- direction. The X and Z axis work as expected as does the spindle.

If both axes move in the same direction in one direction but opposite in the other direction, then it shouldn't be the wiring. Software pairing in CNC 12 had problems?

[Gary Campbell]

Check the direction wire to the left Y driver

[cncsnw]

You could swap the H2 and H3 plugs, so that the X and Y axes get the commands for Z and Y2; and vice versa. Then if your Y direction problem remains with Left Y on the machine it the wiring; and if your Y direction problem moves to the Right Y, it is likely a hardware problem with that direction output on the Acorn board.

[Ken Rychlik]

Basically if it worked before you did the swap, you missed something in the wiring swap. One loose strand of wire to the plug, can mess things up.

I'm surprised to see you are not using the db25 for the step/dir outputs. What are the model number and brand of drives?

[cnckeith]

The machine has a Left Y axes and a Right Y axes that are paired. When I push Y- on the VCP, the right and left Y axis moves in the correct direction (Y-) together. When I push Y+ on the VCP, the right axis moves in the correct direction (Y+) but the left moves in the Y- direction. The X and Z axis work as expected as does the spindle.

If both axes move in the same direction in one direction but opposite in the other direction, then it shouldn't be the wiring. Software pairing in CNC 12 had problems?

no problems.

[SMCNC]

Check the direction wire to the left Y driver

I checked the continuity of the direction wire by putting a probe on the screw that holds the wire in the plugs (on both ends) and got 0 ohms so that makes me think the wire is fine. I made a new harness and installed it anyway. There was no change in the Left Y's behavior.

[SMCNC]

You could swap the H2 and H3 plugs, so that the X and Y axes get the commands for Z and Y2; and vice versa. Then if your Y direction problem remains with Left Y on the machine it the wiring; and if your Y direction problem moves to the Right Y, it is likely a hardware problem with that direction output on the Acorn board.

I swapped the plugs and the problem went to the Right Y axis and not the Left Y axis. The problem moved with the plugs. That makes me think the Acorn board is fine. I rebuilt the wire harness and the problem persisted. It also makes me wonder if there is something wrong with the stepper driver.