An observation was made years ago that PWM base frequency settings can greatly effect cutting and engraving with different base frequency settings producing optimal results at very different frequencies.
I’m testing LinuxCNC/Remora on my K40 and setting up the spindle control so getting deep into what type of PWM(PDM vs PWM) is needed and configuring the frequency of the PWM. So now I’m looking into ways to dynamically change the PWM frequency during a single job. Either using a special M code injected into the GCode or dynamically by setting thresholds on the tool movement average velocity or maybe a threshold on laser power itself. LinuxCNC lets you do those types of things.
Does anyone know if this effect of PWM frequency changes @Ben_Myers Ben_Meyers and @donkjr found and discussed are K40 LPS specific or generally useful to all laser cutters? LinuxCNC/Remora should be able to run on all LPS1768/1769 based boards like Smoothie, Cohesion, SKR, etc so maybe this is of interest to other K40 users.
This might explain what was going on when I was doing a test pattern of dithering and grayscale on white tiles and my grayscale patterns went from white right to black instead of the gray scale and I’ve been using dithering ever since.