I’m experiencing a significant issue with my Omtech SH-G460 laser cutter using a Ruida RDC644XG controller. The X-axis movement has become erratic and jarring. It was working perfectly last night, but this morning, after powering it on, the X-axis started behaving unpredictably.
Issue Details
Erratic Movement: Pressing the left or right arrow sometimes causes the laser head to move to the end of the rail and reverse direction unexpectedly.
Jarring Motion: The X-axis movement is not smooth; it seems to “jerk” or “grind” as it moves, but when powered off, the movement is smooth by hand.
Unresponsive to Commands: Repeatedly pressing an arrow may result in random direction changes or continued movement after releasing the button.
What I’ve Done So Far
Reset to Factory Settings: Restored settings to defaults via the control panel.
Checked Connections: Verified that all cables, belts, and connectors are secure and undamaged.
Tested Belt Tension: Belts are properly tensioned with no signs of wear or misalignment.
Inspected End Stops: Homing and limit switches appear to be functioning correctly.
Tested in LightBurn: The erratic behavior occurs both when using LightBurn’s jog controls and the physical control panel.
Observations
Movement is smooth when the machine is powered off, so it doesn’t seem to be a mechanical issue.
The issue persists after multiple power cycles.
The problem started suddenly this morning with no recent changes to settings or hardware.
I swapped the x and y wires and it is some how now working fine. I think there was a glitch that swapped the x and y signals. Dont know how to fix that.
Sorry, I think you miss understand, the X wires are now plugged into the Y controller and the Y wires are now plugged into the X controller. It is now working as if it was plugged in correctly, but its physically backwards.
Understood completely. I just assumed you would switch the cables back.
The fact that both are working means they got that way because you seated both connectors. If you switch them back and Xaxis goes bonkers, that indicates a broken wire in the X-stepper cable.
Currently with the X wires plugged into the Y controller and the Y wires plugged into the X controller, the machine in working as if the wires are plugged in correctly. The left button moves the laser head left, the right to the right, the up to the back the down to the front.
I ran a few cuts without issue.
Doesn’t this indicate that the machine is reading the signals backwards? It thinks the X plane is the Y and the Y is the X.
Yeah, the travel works correctly only if the cables are swapped. If I swap them back, The X is all erratic again. I checked the device settings and the “Swap x/y output” is not enabled. It also acts weird when I use the machine to move the head even without using lightburn.
Right now the only “fix” I have is keeping the cables swapped. I’m wondering if there is a bug or glitch in the firmware.
This is usually not recommended for Riuda controllers. The defaults are not typically what the laser manufacturer input. Factory settings are what the Ruida Manufacturer determined. At least that’s what I’ve been told.
Now if you restored a backup settings file from when you first got the laser, that’s a different story.
I also tried that while on the phone with Omtech yesterday. They also sent me their factory settings and it still didn’t fix the issue. He is asking some other people and said he would get back to me if he finds a solution. It may require a firmware flash.
have you opened up and read you controller settings in Rdworks? im not sure if he still works there but way back when I had an omtech the only tech that would help was named Murphy so might be worth a shot to ask for him