I keep getting these double lines from my Ortur LM3 20W. Gantry is ok, checked everything and movement is smoother as well. I did other checks on the machine too where movement is concerned. Every design I’m cutting is cutting double lines and oval shapes in the Y-axis. Lightburn preview shows no double lines.
Ortur is not replying to these issues.
Something is loose, or a pulley gets a bit of drift, IMO. Check all belts to ensure tightness. Make sure any cables (anything that moves with the gantry) are all secure and not catching on anything. If you can get to them, loosen every set screw, push head through full X-Y range of motion, wiggle everything, then retighten without shifting it. Even limit switches need checked and tightened. A ‘home’ position isn’t really home if you get .001 of movement each time it tries to go home.
Verify all cables are fully seated in their sockets, from the motors through any USB/power connections. I don’t see it being coms though.
I had a similar issue with my old Atomstack, but it was always belt/pulley related. A ‘missed’ limit switch due to my stupidity (trying to run it past where it should stop) would either jump a tooth or move a loose pulley just enough during the engraving process it would not be in alignment for the next pass. Of course, this might not work for you. But, it’s at least something less you have to check.
Lastly, are you 100% sure the material doesn’t move at all? As you probably understand, nothing can move at all if you want the lines to line up at the end. Air assist, if you run it, can get under a piece of even 1/2-3/4" thick piece of material and float it like it’s air hockey time. Stick it, clamp it, screw it, but do not let it move. I’ve got a trash can full of ‘well, it moved’, from glass to metals and everything in between. If it’s air, it’ll move even pretty heavy stuff quite nicely.
What speed are you running? Try cutting that speed in half. If you have a harmonic vibration issue, the slower speed will reduce the error in the line.
Is your table 100% stable
What is your acceleration setting? $120 and $121
Do you have an overhang camera?
As mentioned above, I suspect cable drag issue but there are many possible sources.
Hi. I’ve checked everything. I did the whole out-of-box settings again. I’ve checked the eccentric screws as well same thing. I always holding pieces to cut/engrave with double-sided tape. I’m gonna do a change over of the timing belts, my last resort.
Hi. I’ve checked everything. I did the whole out-of-box settings again. Cables are completely out of the way. The problem is only in Y. If there’s an X and Y movement, X cut/engraving lines remain slightly solid while Y is going skew. X is NOT the problem.
I’m gonna do a change over of the timing belts, my last resort.
6mm GT2 belts (the ‘usual’ belt on imported machines in my experience) are a lot stronger than you might give them credit for. Unless you’ve worn them down to the cords inside, they’ll hold a medium size child off the ground without issue. While their working tension is low, their weight capacity is substantially higher…something around 125lbs breaking strength. For it to be the belts, when most of those motors run in inch pounds, something else is off.
A bearing sticking, a pulley loose or cable hanging something up, even a motor driver not transmitting correct steps would be my guess long before bad belts.
Hope you find what you’re looking for. I do know it sucks trying to figure stuff like this out.
Oh, and lastly…laser focus?
Try straight lines in both the X and Y.
With my CO2, I can get a ‘shadow’ line to one side if the laser is out of alignment and bouncing off the interior of the mirror housing.
With diode lasers this should be impossible, but one of the stacked diodes and lenses might have shifted, giving you that extra line.
I’m grasping at straws right now, so best of luck.
