I’ve been running my S9 as it came for several months with no problems.
Bought the y-axis extender rails from Amazon. Instructions were laughable: Take it apart. Reassemble.
The new cables had color-coded plugs to match the color-coded, size-matched, and keyed connectors on the board, so I’m certain I connected it right.
Plugged it into the computer, fired everything up, and voila! It works.
But wait: on any job with a total path length over 25mm, when I start the job it performs for a split-second, then pulses in both motion and laser firing. After a few pulses, the job ends and the laser head “returns to origin” at distances I estimate to be the distance it should have travelled if the full job would have run correctly.
A single straight line, horizontal or vertical, under 25mm appears to fire fine.
Test fire works. Jog commands from the Move tab work, including shift-arrow and ctrl-arrow.
Created a square in the center of the workspace 25mm square.
Frame works. Shift-frame fires the laser at test level and movement is correct.
Press Start, and the odd behavior repeats.
Tried the previous “Sculfun” device that I used previously. Same results.
Used “Discover my device” with same results.
Tried four different USB ports on the computer. Same results.
Manually set up the new device, selecting GRBL and COM port and defining bed size. Same results.
Changed the communication type from buffered to synchronous. Same results.
Tried different movement speeds and laser strength settings. Same results.
shut down, re-set the cables on the servos and laser head. Rebooted the computer. Same results. (I haven’t opened up the case to double-check the board ends of the new cables are correct - but again, they only go on one way.)
I have a 10-second video that shows the problem but I can’t see how to upload an attachment.
To rule out a hardware or software problem: could you try to laser a slightly bigger rectangle using LaserGRBL? Just to make sure it’s no setting that interferes.
Do you get any error messages in the console window?
If you move the gantry manually, do you feel any resistance?
@misken I’m going to have to get lasergrbl. I’ve been very happy with Lightburn, and it was working Tuesday night.
I’ll check for errors tonight.
The gantry moves as it did before the upgrade in both axes with minimal resistance.
The error happens regardless of the direction of motion alone the x or y axes, or at an angle.
Further testing:
I replaced the new cable that came with the extension kit, putting the old kit back on.
With the old cable, everything works as it did: frame, shift-frame, and burn.
With the new cable, I get the same results: frame and shift-frame work, but the burn fails in the same way.
In between every test, I:
closed lightburn
turned off power to the laser
disconnected the usb and power from the control box on the laser
disconnected the cables
installed the other set of cables
plugged the usb and power back into the control box
started lightburn
opened the same file
powered on the laser.
I didn’t change any settings or do anything with the software.
I don’t have limit switches, I don’t have return to origin turned on, and I can manually moved the laser head to any coordinates within reach of the cable, with the same results. I also don’t have “Warn me if the print might be out of area” turned off, so the controlled has no idea how big the bed is.
I’m convinced it’s the cable.So I got out my trusty multimeter, and I have good continuity from the red and blue connector at the controller end to the three pins on the laser head end of the new cable (one line at a time, of course) and there are no shorts among the three leads.
Unless there’s some magical way that the cable is communicating to the laser that I changed the side rails of the frame, I’m at a loss.
Did you also check the other cables? I suspect a problem in the stepper cables. Possibly shorting out or causing a current spike that’s disrupting the controller.
To me, it sounds like a broken cable as well. Usually, those cables break inside the shielding, directly at the plug. And it’s usually no complete connection loss because the wires are still touching each other, depending on cable bending. So, you can test by steady firing the laser and turning and twisting the cables while plugged in. The laser should flicker again. Or it’s a loose connection between the plug and connector.
Well, RATS!
Took the new cable off, and I’m experiencing the same thing. With a larger file, the burn proceeds for a random amount of time (under 40mm approx in repeated testing) then the same problem appears.
Tried it with a “real” file (shelf sides) and I get the same bhavior. It almost seems like every tie there’s a direction change, I get a single pulse, At random times, it’ll butn the “full length” of the cut apparently, then go back to the odd behavior.
Multimeter testing shows continuity is good on all cables (old and new) from connector to connector.
Test fire and wiggle the leads on both cables, and no flicker in the laser (assuming my eyes would pick it up if it happened.
Set the firmware to the 400x900 size per Misken’s page that he referred me to i the FB group.
Checked and rechecked all belt tensions and free movement of both axes.
It’s possible I goobered the control board when I was swapping cable, but I doubt it.
You’re saying using your original cables you’re experiencing the same problem?
I’d suggest taking a look at your power supply. Test to see if you’re getting proper voltage. It also may be failing under load. Do you have another power supply you can test?
Success!
It turn out that changing which outlet I plugged the laser into made a difference! The power strip the previous owner of the house put up was good enough for the computer and drill chargers (my laser is in the garage), but the ground was just bad enough that it was messing with the laser.
At least, that’s the best explanation I can come up with.
With the extended cable installed, I’ve had two successful burns. And I’m happy once again. Even better, I’m productive once again.
