Knocking noise/stepper losing steps, but only when laser is on

[m_g]

Hi all,

80W chinese laser with Ruida controller, Lightburn software. Has been working well up until today, no changes have been made (that I'm aware of-the machine is still new, is it possible to accidently reset factory settings?) Now the machine randomly makes a knocking noise, and I get missed steps resulting in broken lines, or straight lines become misaligned as the laser skips appx 0.5mm to the side. FYI I am cutting at 100mm/sec.

Strangely, it only does this when the laser is active, if i turn the laser off, and run the same code, there is no issue.

What could be going on here? Any assistance much appreciated

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[Vlod]

Could be not enough power, if you said it would run cnc fine without laser.
I would try different power supply or isolate laser on a different supply line and check how much it actually take.

[joeavaerage]

Hi,
another possibility is that electrical noise from the laser power supply is being conducted into the power supplies for the electronics. Good quality EMC filters on each and all 230VAC inputs
is a worthwhile investment.

https://nz.element14.com/corcom-te-c...ase/dp/9586474

Craig

[m_g]

Thanks Craig, I assume there is a laser power supply, and then a separate supply for electromics? Do you mean place a filter on each of the separate supplies, or is the filter installed at the AC wall socket to filter power from the source?

Thanks

[joeavaerage]

Hi,
I am presuming that there is a switch mode power supply to the laser, and that its electrical switching noise is upsetting other more sensitive circuits.

You need to separate the 230VAC supplies, one to the laser supply, and the other for the PC/electronics. I would put a line filter on each AC supply.
The filter on the AC input to the laser will prevent any noise from coming back out of the laser supply to pollute the 230VAC network, and the filter to
the PC/electronics will stop any residual conducted AC network noise from being carried into the PC etc.

Craig

[m_g]

Thanks, this is the setup, it looks like there is a power filter, but maybe only setup from the mains onwards (nothing separate for laser and electronics supplies)?

[joeavaerage]

Hi,
I would put the line filter on the input to the electronics and/or PC and try it. The filter needs to prevent potential noise from the laser power supply from getting into the
electronics, so the filter must separate the two.

If it works then get two two stage line filters, the single stage filters don't attenuate the noise nearly as well.

Craig