Line cutting in brass: strobing and flashing and losing focus

[Brad2 (Bradley)]

I am using a Gweike Max 50W galvo/fiber laser, using the line cutting tool with wobble (thanks to this forum for that tip), the settings works usually great, but lately the cutting is very uneven and the laser focus seems to glitch out several times, the laser begins strong and loud. But slowly decreases to be invisible, and only the red focus laser visible. When cutting a circle for example, the laser flash is almost strobing/flashing, and when the job is done one can see where it was flashing, since half of the circle has little or no cutting at all. While the other half is cut through completely.

Just touching the electric lift (either up or down) immideately makes the laser go boom and is instantly very loud and bright all over the circle again.

The problem doing this 10 times every minute for a job that has over 1200 passes is not optimal, since the constant hoisting or lowering of the laser during work makes the end result blurry and I often end up with multiple (close to each other) lines, where in the optimal world there would be one that pierced the brass sheet completely.

I should mention that usual deep carving seems not to be affected and works good.

Anyone that experienced something distantly similar?

[NicholasL (Nicholas Leqeta)]

@Brad2

the laser begins strong and loud. But slowly decreases to be invisible

Mark or note the position of the galvo head to make sure there is not any z-creep or any indication of unwanted physical movement that would change the focus.

@Brad2

Just touching the electric lift (either up or down) immideately makes the laser go boom and is instantly very loud and bright all over the circle again

Power fluctuations like this should not be happening, contact the the machine supplier for troubleshooting advice. Does the unit feel hot?

@Brad2

usual deep carving seems not to be affected and works good.

Odd symptoms, maybe the higher power settings of the cut might be overloading the machine or somehow causing the power supply to become unstable?.. a brief increase to the power load from using the z-lift might have a momentary stabilising effect?..just throwing out some wild guesses.

A couple of tests you can do:

• Try running the deep carving at similar high power setting as the cutting - as a test - to see if that will results in problems also.

• Try letting the machine cool and then running a cutting job where you have decreased the cutting power by 20-30% to see if that results in longer periods of cutting before you notice a loss of cutting intensity.