I have an ortur LM3, and the latest build of lightburn. Completely vanilla with no mods, plugins or after market upgrades.
My problem is thus, If I draw a single large circle in the middle of the screen it cuts out slightly oval and the start and end points are slightly off so it doesn’t join up. There is a little tab left between the circle and the rest of my material rather than a neat cut all the way around.
The smaller the circle the worse it gets, it my circle is less than 1cm, it’s almost egg shaped and the line is way off of joining up. There is no noticeable difference if I’m cutting in the center of the cutting area or out towards the edges.
This happens regardless of how I draw the circle, even using the circle tool from the Lightburn menu.
I’m not sure if this is a hardware or a software problem. From general browsing this could be due to the belts not being tight enough, my steps being incorrectly set, my cutting area not being correctly set for the LM3, it not being properly homed, and half a dozen other things.
The problem is that I’m not really sure how to check any of this except for the belt tightness, which I would like to leave for last, as I can restore my software setting from a backup if I do something silly and make it worse, but if I change something on the hardware I can’t do that.
So, could I please have some assistance in checking the software parts, a dummies guide if possible.
I already know that my software configuration wasn’t set up correctly from the start as I’d managed to set my laser to be 255 instead of 1000, so all of my cuts were taking 4 times as long as they should.
This sounds like a belt tension issue. If the circle is squashed on the sides, your issue is with the x-axis. If it is squashed on top/bottom, it’s the y-axis. Check your belt on y-axis and tighten it as instructed in the videos that probably exist for your laser. If your x-axis is on a gantry tighten all screws accordingly.
This is virtually always a mechanical issue. Do as @ednisley suggests AND physically check set screws with an allen wrench and feel for any looseness.
Everyone wants to make this a software issue before finally giving up and checking their machine.
I’m not saying that it’s not a hardware problem, but I’d like to explore software first as you can back up software settings so if you make things worse you can always just go back.
Can’t do that with hardware.
Slipping belt or incorrectly set homing were my first thoughts.
Neje appears to have different firmware tables for their app than used in their conventional g-code handler. It seems conceivable Ortur would as well. They may have more conservative acceleration/speed/overscan settings for the app. A sloppy drivetrain could be masked by slower vector changes.
I’m not familiar with LaserGRBL but you would want to compare all speed and acceleration settings.
In LB, type $$ (enter) in console and copy/paste the entire result here for review. Also paste all cut/layer settings. If you can do the same for LaserGRBL, it would helpful to have that as well.
You also said you weren’t interested in checking for loose set screws, etc.
Until the most common reason that everyone has this same problem is eliminated it’s hard to move to software as the issue.
I have yet to see this problem anything other than mechanical, but anything is possible. And you’re not giving people here trying to help confidence that you’ve gone thru and checked couplers, drive pullies with an allen wrench to move to other lesser possibilities.
It was a software problem, deleted device profile and reinstalled using settings on ortur forum. Problem solved.
No idea which settings were wrong, but since I have already had problems with incorrect software settings I seems like I simply didn’t install it properly on day one
I came to the lightburn forum looking for help with lightburn, since I didn’t have this problem with my two previous packages.
