Hi everyone,


I’m facing a recurring issue while cutting carbon steel with my self-built fiber laser machine, and I’m hoping someone can help shed some light on it. The machine uses a Raytools BM109 cutting head, a Raytools XC3000S controller and software, and a BWT 1500W fiber source.

Here’s the situation:
Sometimes, a small burr forms on the material during the cut, usually on small details, but this isn’t really the main problem. When the nozzle comes into contact with this burr, the cut cancels, which is expected. However, instead of the cutting head retracting immediately, it plunges downward into the workpiece, damaging the nozzle in the process. After this happens, the head finally moves up, and an alarm is triggered.

I’ve also noticed that this happens when cutting small letters or features that don’t fall out of the workpiece immediately. If these small parts tilt slightly upward, the nozzle can make contact with them. The result is the same: instead of retracting as it should, the head moves downward, crashes into the material, and damages the nozzle.
I have, of course, performed all the necessary calibrations, and apart from this specific issue, everything works perfectly. The head only moves in the wrong direction when something goes wrong, which thankfully doesn’t happen often. As a workaround, I could raise the nozzle height, but this compromises the cut quality and feels more like a quick fix than a proper solution.

Could it be that there’s some kind of safe height setting that needs to be configured? Perhaps this is currently set below the material’s surface? I know similar settings exist for some milling machines.
However, I haven’t been able to find anything like this in the Raytools software.
Has anyone encountered a similar problem, or does anyone know why the cutting head might be moving downward instead of retracting when it hits an obstruction like a burr or a tilted feature? Any advice or suggestions would be greatly appreciated!

Thanks in advance for your help!

Best regards,
Eddy