I don’t have cable extension just longer cable (2m vs 70cm iirc from Aliexpress). Z stop problem occurred only on far side (with longer cable) and completely gone after soldering resistors in.
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funny you should say that. the z stop on the right side (the one w/ the extension) had the issue I had to put a jumper on to solve.
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Mine was on both sides
Was the faulty/malfunctioning end stop connected via the >original< wire only?
My endstops didn’t come with wire.
If you want to test your theory, just unplug your endstops and measure the impedence between the wires with the switch in a closed position.
This dropping thing only happens for me if I drive the Z axis too high, while not during homing. I gather that driving the Z “shuttle” part up into a collision with the top of the YZ plate causes a skipping of steps that throws the magnetic grip of the motor out of sync / causes it to be confounded, and since that (driving Z into a collision) is exactly what happens during homing whenever homing switch is not working, then I strongly suspect that the same thing that happens for me when I cause a collision while not homing, would also happen during homing, if an end stop switch is not properly triggering, or not sensed when it triggers.
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This is happenningall the time , anytime i drive the z to home, i have to hit the emergency stop button, and reset the power.
If this is the solution- installing resistors to the board as shown then i will pull it all apart and solder in some.
do i really need to do for all, or just the one for Z2?, or do both Z switches? I dont have any problem with X or Y? If I do all, will this cause any problems with the touch plate, if at all?
I also noticed that it shows a continually changing z position, I gather that it will stop this fault too?, I hope so ,as I would like my Z height to show up as constant.
how do i set home as zstop @ 200mm? in settings?, once it is all done?
This is happenningall the time , anytime i drive the z to home, i have to hit the emergency stop button, and reset the power.
It is unclear to me that your problem and the problem above (SKR Pro pin read) are the same issue. I recommend opening a new topic with an explanation of your exact problem. If it turns out to be the SKR Pro issue, you only need to add resistors to endstops that are failing. While soldering the resistors is a clean solution, you can add the resistor to the endstop wiring instead.
Make sure you are not actually hitting the top of the slot with the Z axis stub, before it hits the switch. If you are sure that is not the case a resistor could help if you are sure your wiring is tight and secure.
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This is very unlikely. The resistance of even a very long extension will still be in the milli-ohms range. A 2m extension is 4m of loop area, which is 300mR for 24AWG/0.22mm² wire. That impedance would need to be significant relative to the 4.7kR pull-up resistors for it to be an issue. What’s more likely is that the extra cable length is causing noise pickup that is dropping the voltage on that cable enough to drop below the trigger threshold periodically. The solution to that is to use lower impedance pull-ups or to add filtering. In this case, the issue has previously been identified as being incorrect pull-up impedance. This wouldn’t have been found because it’s likely not a 100% end-of-line test or, if it is, it’s a test setup where the inputs are being driven by a digital output, not an actual contact, meaning the pull-ups themselves aren’t being tested.
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I was thinking that the z stops, and the top may be very close in distance, so I made some taller wedges to go on plates, for z stops/ switches. This seems to have fixed the homing problem.
I now have about 6 mm gap at top after homing, this gives more than enough z travel for my projects, I am not planning to build anything too tall- as you say, it is more sturdy towards the bed area.
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Thanks Ryan.
I fitted some larger spacers to the XZ plates at the Z stop switches, I won’t really need to use the full height, I don’t think? And it stopped- I thought it was close, and maybe was a possible problem, but no longer a problem!
… unfortunately, I work days, and the evenings and nights are bloody cold here(Perth, Western Australia), so I have not ventured out to my shed, to tackle remaining small problems I have, but that’s for another post.
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