Diode laser not firing accurate

[M199117 (Jerardy)]

Hi

I can’t figure out what the problem is,
I have a 1000x1500 laser frame (1 x stepper motor, 2 y stepper motor), with a longer ray 5 controller, and 20w longer laser
but the laser keeps firing with every line 2 mm to early, first from the left side and then with the second line from the right side.

i have checked the frame for any lose bolts, also the tension on the belt.
I tried different speeds but the problem still remains.

I couldn’t find any topic with the same problem I hope that anyone can help me

[ednisley]

@M199117

checked the frame for any lose bolts

Scale this test pattern to fit the platform and run it as fast as it will go in Line mode with optimizations turned off and power set to mark cardboard:

GrundTest.lbrn2

Any distortion in the results on the cardboard indicates a mechanical problem. Upload a picture of the results so we can look over your shoulder.

After that runs correctly, then Scanning Offset Adjustment may be relevant:

Scanning Offset Adjustment - LightBurn Documentation

However, a 2 mm offset distance on a diode laser is extremely large, so it’s most likely a mechanical problem.

[JimNM (James)]

What speed are you running the test at?

Try running at half as fast, just for grins. Many lasers advertise an absurd top speed CAPABILITY… just because it says it will cut at 29,000 mm/m does not mean it will do so with good results.

My speedometer on my little commuter car goes to 140 mph … but it won’t ever see that speed unless I drive it off a cliff.

The stresses involved in repeating acceleration while the laser head is moving back and forth can easily be multiples of G force. That will cause distortions in the laser engraver frame and in your results.

Give it a try and let us know how you do at slower speed.

[M199117 (Jerardy)]

So I made a couple of software and hardware adjustments.

Hardware: one of the wheels was just to tight so that made the belt expand a little bit what caused the offset of the beginning of the laser.

i also noticed that when I was engraving lines I had wobbly lines, that was because my acceleration was to fast that made the 1500mm x frame shake so I adjusted the acceleration of the y axis lower what solved the problem.