Laser newb lining up job on ender3

New lightburn user, feeling like Im brain damaged here. Ender3 running Marlin2 bugfix with crealitys laser attached. I can not position my cuts/engrave to save my life. Ender3 0 is center of the bed. I have a start Gcode set that homes all, then raises Z 50mm as thats where my focus is set. Then the last line of Gcode moves the laser to the front left corner of the bed, which appears to be lightburn 0. I am sending jobs via octoprint or SD card, not direct connection. I have lightburn set to start from current position. I have my cut lined up in Lightburn on 0,0. There is really no predicting where it will start cutting. Sometimes its exactly on target, other times its slightly off the center of my bed. I dont have any offsets set in lightburn, so I really cant figure out whats going on. Everytime Im confident i have the positioning figured out, i send a job and it could possibly be cutting off of the bed entirely. Im really at a loss. Are the visible options in the Lightburn UI only applicable to direct connection?

If I run this via a terminal, I land on front left corner of the bed, which should be Lightburn 0. I dont have auto home set in lightburn, or offsets in the machine settings or layer. Have Start From Current Position set. I still cant predict where the cuts will start. What am I doing wrong?


G1 X0 Y51

G1 Z50

To add to this, at random times, sending the same job to the printer, the laser will position over home, and just fire without moving. I can cancel the job, send the job to print/burn again, and it may or may not move X/Y axis. Ive stripped all GCODE out of my machine definition and just manually home before sending the job.

Discovered with no GCODE in machine definition, no movement except laser fire when sending a file.
I added a home X,Y to the start gcode, then set my laser offset of 51Y also in machine definition. 3 burns so far, reliably where i think it should be. 1mm sec at 100% power to get engravings on aluminum business cards. Cheap laser was a good entry point and learning experience, ill be upgrading to something more powerful soon.

Glad you got it sorted. :+1:

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