My Lowrider V4’s Y-min motor isn’t moving when I tell it to move 100mm via the touchscreen interface. The Y-max motor moves but the y-min either doesn’t, or rolls a little because the y-max is moving.
I’ve tried plugging it into the X-axis instead so I can tell it to move on its own, and I’ve taken all tension off the y-min belt to rule out excessive tension. I know the X-axis works as I’ve tested it already. But when I tell it to move with the y-min motor connected, the stepper motor clicks once, sits there for a few seconds, and the controller then gives the error: Printer halted: kill() called.
I can pull the belt through the motor and it rotates; I don’t know how freely it should rotate but it’s not jammed. I’ve got continuity on all four stepper wires (i.e. near-zero resistance between wires 1 and 3 and likewise between 2 and 4).
I wondered if it was a bad connection to the board, so I’ve soldered a better end onto the cable; one that seats properly in the socket and locks into place. Hasn’t helped.
I’m more than slightly mystified - has anyone else experienced anything like this?
(edit) it gets worse. If I tell it to move the Z-axis either up or down, maybe four times out of five the Z-max motor keeps driving downwards unstoppably until it runs out of travel and sits there skipping steps. I have to turn the whole thing off to stop it. One time in five it will behave impeccably and go 10mm up or 10mm down as instructed.
Tried some more troubleshooting - swapped the 2209 driver boards around to no effect. I’ve still got an X channel and y-max that work beautifully, y-min and z-min that click once but don’t move, and a z-max that thinks I want it to dig for oil. It has to be either the SKR Pro or the firmware at this point.
Curiously, the z-max problem doesn’t seem to occur in Marlin mode. y-min and z-min still won’t move though.
Have you confirmed your limit switches are working correctly and are not wired backwards. As in the machine thinks it’s at its max point and won’t move ?
So, I’m struggling to get good connections for the limit switches. But swapping motors between channels sees the fault staying with the motor, i.e. the X axis motor works fine when plugged into X; it also works fine if I plug it into y-min. The y-min and z-min motors, in the mean time, doesn’t move regardless of which channel it’s connected to.
I’ve checked the y-min motor resistance and I get 2.4 ohms across each coil; the fact that they match one another seems good, and this resistance is within spec. I’m measuring from the controller end of the wire.
Found it. And so help me, it’s a bit ridiculous.
I bought a pack of five stepper motors. It seems that these five externally identical stepper motors have different wiring configurations. Three of them have wires 1 and 2 connected to one phase and 3 and 4 to the other. Two of them have wires 1 and 3 connected to one phase and 2 and 4 to the other.
I’m mildly astonished, but mostly just hopeful I might have found the fault.
Why the z-max motor goes insane when commanded to move in touchscreen mode, I’m less sure. But one unlikely problem at a time. Will resolder the wires on these two motors and report back.
That’s sorted it.
Can anyone confirm - if I tell the Z axis to move but it thinks it’s up against the limit switch, will it lower the Z to try to come off the limit? Wondering why it was lowering until it ran out of travel and an intermittent connection on the NC limit switches might explain it. Better connectors are in order, I think.
I learned a while ago that you can’t trust the colors on stepper motors, even from the same supplier. The good news is that they don’t break themselves when wired incorrectly, it just sounds like they might.
Hmm, that’s a bit concerning then. Since fixing the wiring, it’s not done it again, but I’ll wait and see for a bit. I don’t fancy having it ramp down through a job mid-cut if I can help it!
I’m still getting used to the specifics myself, but the limit switches are only ever registered and react on homing. I don’t know how many times I have crashed the upper limit of Z because I manually moved the Z height too far while setting up the machine.