/diy/ - Do It Yourself

>>2758527
>check g-code from manufacturer's software
>see M3 P100
>i've been using M3 S__ instead of P__
>can't find any literature on P__, just a couple of posts on the snapmaker forum
>https://forum.snapmaker.com/t/fixed-spindle-speed/2146/3
>I just received my SnapMaker and have tested setting the spindle speed with the M3 S[speed] command and indeed, the speed does not change no matter what values I enter for speed
>but laser g-code does have variable duty-cycle
>so i need to fool my snapmaker into thinking it has a laser connected
That means changing the file extension from .cnc to .nc and replacing a 100Ω resistor with a 130Ω. More importantly, it means adding a MOSFET, which may need a driver circuit too if the drive voltage and current is too low, and cramming that inside the driver housing. But somehow the chip used on the laser driver (XL3005E1) doesn't have a PWM input, but rather it does this weird circuit with a diode? If the PWM frequency is too low for the 12V motor to not pull stupid amps, I'll have to add an LC filter and a freewheel diode, turning the PWM circuit into a buck converter. Sounds kinda fun I guess. Makes me wonder why the MOSFET inside the thing can't be used for PWM though. Or why I can't change the PWM frequency to be higher. Really wish I could flash a custom version of marlin right about now.