SOLVED: Burn Marks Alongside Cuts

[Khayl (Abdulrahman Allahyani)]

Hi everyone!

I’ve been using my 130W RECI laser with a Ruida controller for almost a year now, and it’s been running smoothly until recently.

Lately, I’ve been noticing strange burn marks alongside the cut in specific locations. This seems to occur mainly at the top-right and slightly on the bottom-left of the material. I haven’t made any changes to the setup prior to the issue appearing.

I’ve attached a picture for reference—any insights or advice on what might be causing this would be greatly appreciated.

Thanks in advance for your help

after the nozzle

[Khayl (Abdulrahman Allahyani)]

This test is done on 4mm acrylic, the sides are smooth with 30% power 6mm speed

[Kuth (Luis Jardim)]

I think that’s a mechanical problem (something slightly loose).

@Khayl

the sides are smooth with 30% power 6mm speed

6mm/Sec. or 6mm/Min.? Probably “/Sec” but we need to know for sure.

[Khayl (Abdulrahman Allahyani)]

You are right it’s /Sec.

[Khayl (Abdulrahman Allahyani)]

@Kuth

Probably “/Sec”

You are right it’s /Sec.

[ednisley]

@Khayl

strange burn marks alongside the cut

Verify the beam emerges from the middle of the nozzle with plenty of clearance all around.

The beam seems to enter the laser head in the middle of the aperture, but that does not ensure Mirror 3 angles it correctly through the entire head.

A quick check: stick tape over the nozzle and fire a brief manual pulse. The hole should be in the middle of the circle formed by finger pressure on the inner rim of the nozzle.

Sometimes things can work loose without permission:

We’ve seen cases where the lens clamp ring has come loose, with the lens rattling around inside the head. The mirror clamp ring can do the same thing, letting the adjustment screws feel right with the mirror flopping around.

[Khayl (Abdulrahman Allahyani)]

@ednisley

A quick check: stick tape over the nozzle and fire a brief manual pulse. The hole should be in the middle of the circle formed by finger pressure on the inner rim of the nozzle.

Although it seemed fine and in the middle, I did very minor adjustment for the 3rd mirror and that did really help.

I did not expect that, especially how it occurred.

@ednisley

lens clamp ring has come loose

Before I did the test, I replaced the lens (and scratched the old one in the process ).

thankfully it’s just alignment.

Thank you @Kuth and @ednisley .