So I think that the SKR Pro V1.2 board endstop issue is causing the Z1 motor (non rail side) to travel past the endstop switch during homing (despite me adding 1.2 kOhm resisors between Sig and VCC). But the thing that is puzzling to me is that the Z axis on that side falls to the spoilboard immediately as soon as the stub touches to top of the YZ plate, rather than skipping steps. It seems that the motor is losing power for a few seconds, then resumes trying to home.
I had the endstop issue happen previously on the Y2 motor and the Z2 motor, and those would just make noise and skip steps, but the motors wouldn’t shut off the way Z1 is doing now.
Is there any reason why this would be happening? (I mean the shutting down instead of skipping steps, not the fact that it is not stopping when it hits the endstop switch)
It’s wired NC, with one wire to SIG, one wire to GND, and a 1.2 kOhm resistor between SIG and VCC. Wires are soldered in place from my earlier build which worked 100% of the time, and works some of the time now on this build.
The board itself doesn’t seem to be resetting, as the other side (Z2) doesn’t drop, and the LCD screen doesn’t reset when the Z1 drops.
Triggering with my finger doesn’t stop the travel during homing intermittently, which is why I suspect the SKR endstop issue (despite adding a resistor). I can’t do a M119 until it stops moving, but I’ll do a bunch of tests tomorrow when it isn’t moving to confirm the endstop issue. But again the mystery isn’t the endstop issue, the mystery is that it drops rather than skips steps.
I’ll shoot a video of the symptoms and take pictures of the wiring tomorrow as well.
So of course when I tried to do some troubleshooting this morning, the endstop issue went away and everything homed perfectly for 10 tries in a row (last night was about 2 of 10 at best). But what hasn’t gone away is the Z1 motor falling down if it hits a solid object, while the Z2 just skips steps .
That does not look like what it sounded like when you described it.
I would try swapping the Z1 and Z2 motors and end stops. This will still work. If the problem stays on the Z1 side, then look at the motor and wiring. If it moves, then you need to look at the board itself.
