Layers shifting position when cutting

Hi,
I’m new to lightburn… on the trial for a couple of days and pretty new to cnc carving / lasering (a week).
I’ve been testing a few projects, learning as I go along… many errors and tweaks along the way, but I’m getting there… this issue though has me stumped…
I’m cutting a multi layered project (4 layers), starting position as ‘current position’. before i start I set home nonetheless and set origin (though that shouldn’t make any difference when using current position I believe). I also fire the low powered laser and plot a course around the extremities of the project to check all is within the expected bounds…
Everything so far checks out, but when i cut the project, invariably the whole project starts in an unexpected position or a layer will drop a centimetre mid cut. Out of approximately 10 cuts I’ve only had 1 success. Can you advise what I need to check to get this working correctly?


What I want…

What I’m getting most of the time…

Thanks,
Dave R

I think this was related to speed of cut, I hadn’t altered the settings from 6000mm/m as I think it defaults to the machine’s configuration if over.
However on watching the cut take place, particularly the small text outline it was apparent the speed setting was too high. dropping it down to 1000mm/m and lowering the power level for that layer seems to have solved the problem. I’m getting consistent results now

The speed definitely is the issue. I suffered the same problems when I set mine up as well. Depending on your hardware, and work surface it’s resting on. I discovered that my entire laser frame was actually shifting as the head moved. I found some 3D printable braces that can be screwed into a wasteboard, that could be an answer for you as well if you’d like to up your burn speeds.

Thanks Daniel,
Yes definitely a speed issue, plus I hadn’t stuck the workpiece down at all… just lay it flat on the spoil board (completely new to cnc lasering). Having tweaked speed and power settings and a touch of hot glue to secure… I get consistent results now. So much so, that I was happy to try my first real project…