I am having issues with my Lightburn setup that is causing the pattern to shift to the left. At first I thought it was an issue with my machine Millwright MegaV so I took apart my X axis and made sure there was no slipping but even after adjusting the motor to the gear teeth everything moves as it should. Next thing I thought was the USB turning off and going idol so I fixed that. Then I thought maybe when I imported a file from Imagr something went wrong so I imported a picture directly to Light burn and it did the same. It seems every time I got to hit start I get a Cut might be out of bounds - continue anyway alarm but the preview looks right. If anyone could help it would be greatly appreciated im at my wits end.
Here’s the description I see for the X and Y axes:
X and Y Axis Drive Mechanism: Precision 20 Diametral Pitch Rack with Hardened Steel Pinion
I assume the rack is securely mounted and even if not, can’t imagine this much drift occurring without you noticing.
How is the pinion attached to the stepper? Is it attached directly to the stepper shaft? If so, check for any slip of the pinion and make sure it’s secured well if there’s a grub screw. If this is loose it could be slipping and losing steps. Focus would be on the X-Axis.
The other consideration is that you could be moving too quickly, either acceleration or speed. What are your acceleration and speed settings? You should be able to hear a whine from the motor if the steppers are losing steps.
Are you using this machine also for CNC routing? If so, have you seen any similar issues there? What types of speeds to you run? And what software?
Found an assembly video for the unit and got some insight. A few additional notes:
The rack definitely looks like it could slip if not securely mounted. Make sure there’s no lateral travel of the rack. Again, focus on X-axis in this case.
Pinion slippage is valid, please check
Double-check wheel tension to the track. Make sure it’s not too tight and causing it to drag. The entire head should be able to move fairly freely but without “slop” or wobble from having a gap between the wheels and track.
I did loosen up the rack and reinstalled making sure the gaps were correct and the drive gear is secured and double checked. I will try the router aspect as soon as I get off work.
Ran them router on UGSplatform on something with multiple layers and depths and it ran fine. Thank you for the tips btw. Seems its just Lightburn that is acting up
Did you make any hardware adjustments before the router job? I highly doubt the type of issue you were having would be caused by LightBurn. LightBurn issues would be much more repeatable.
What were the speeds/acceleration used for the router? How do they compare to the speeds/acceleration you had on the burn?
I didnt make any adjustments other than taking the lazer off the spindle. I also ran speeds as fast and much faster with the router so im at a loss on this one.
Both burn and router work were in the same location because I really wanted it to mess up to narrow down what’s wrong and it ran fine. No unusual noises. As for alignment I square the piece down. Move the laser to position of my origin then hit set Origin. At this point I always get a warning cut may be out of bounds. And it will run fine for an inch or so then drifts left from there. The previews always look good though. Pretty much same process as the router through UGS
Hmm… sounds like you’ve got some coordinates issues going but they shouldn’t be causing what you’re seeing.
Try one thing… in LightBurn use the Save Gcode button in the Laser window to save the gcode to a file. Run the Gcode through UGS and see if you get the same behavior.
This reinforces to me that it’s not what LightBurn is generating necessarily. You should try the original burn that you posted in UGS and see how it behaves. It could still be something in the cut settings in terms of speed but otherwise not a problem in the actual gcode.
This to me still feels like something losing steps. One thing you could try to do is to slow down the burn a lot and see if it completes cleanly. If it works, then may be easier to trace down exactly what’s causing the error condition.
So I ran the same file that was giving me issues (well anything in LB gives me issues) on Lightburn by saving the Gcode and putting it on UGS. I marked off the 6x8 square it is set for and ran the program with the router bit just hovering the surface. Everything stayed in bounds so that might rule out the machine.
Just ran the gcode without hooking up the laser in UGS and since there was no depth I set the router bit the same place I would have referenced the lazer. Mainly was just watching the path to make sure it didnt run out of the 6x8 box I drew. I didn’t know I could run the lazer through there. I will look that up tomorrow and try.
I’m wondering if there’s a stray pixel to the extreme right somewhere that almost invisible to see. If so, it could move your output to the left to attempt to capture everything.
Did you try to “Frame” your output on the material before actually engraving?
Can you upload the original image for other’s to look at and possibly try?
