#Gantry z motors mess

51 messages · Page 1 of 1 (latest)

mortal hawk
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Do not know reason way my z motors look like going different speeds. Even when I Try qgl after homing, an manually squaring everything (with motors off) , it finally fails due excessive tolerance. I attach my klipper, only weird thing I can see is

TMC 'stepper_x' reports GSTAT: 00000004 uv_cp=1(Undervoltage!)
TMC 'stepper_y' reports GSTAT: 00000004 uv_cp=1(Undervoltage!)
TMC 'stepper_x' reports GSTAT: 00000000
TMC 'stepper_y' reports GSTAT: 00000000

TMC 'stepper_z' reports GSTAT: 00000004 uv_cp=1(Undervoltage!)
TMC 'stepper_z1' reports GSTAT: 00000004 uv_cp=1(Undervoltage!)
TMC 'stepper_z' reports GSTAT: 00000000
TMC 'stepper_z1' reports GSTAT: 00000000
TMC 'stepper_z2' reports GSTAT: 00000004 uv_cp=1(Undervoltage!)
TMC 'stepper_z3' reports GSTAT: 00000004 uv_cp=1(Undervoltage!)
TMC 'stepper_z2' reports GSTAT: 00000000
TMC 'stepper_z3' reports GSTAT: 00000000

Board is new, drivers (5160) also rc all 0.8 he all 0.3 motors all

17HS19-2004S1

Psu mean well 500 , could it be faulty? In a steady state , it provides constant 24.2 v

Z belts all 5.6/5.8 range with boquilla belt tensioner

Thanks in advance

📎 klippy_4.log
zinc marsh
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There was someone else having the same problem a week or so ago, also running TMC5160's on Z. My guess is that all four Z motors with 5160's starting to move all at once is a sizeable current spike, causing a voltage drop, causing that uv_cp=1 error.

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(The error doesn't necessarily mean "voltage is too low", but usually at least that voltage is fluctuating)

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Might help running beefier power wires, and maybe splitting the motors between "main power" and "motor power" (as config suggests you have an Octopus Pro).

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That error means the stepper driver isn't stepping for a brief moment, so the motor is missing steps and lagging behind the others, making them move at seemingly different speeds.

waxen geyser
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someone else also recently discovered they had the wrong pulleys on some of their z drive stepper motors

zinc marsh
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yeah, different size pulleys in the Z drive could do weird things. still wouldn't cause that stepper error though, and without fixing those the printer will never run reliably.

waxen geyser
mortal hawk
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Pulleys are all the same, motion difference should be much bigger , i.e 16/20 teeth, 4 teeth per turn would make motion much more different , no? I could be mistaken , I am quite newbie

mortal hawk
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On the other hand, does it make sense to try a different psu, this one has seen a lot of ‘accidents’ ( I have lost the count of ruined boards and drivers..)

zinc marsh
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It's not certain that this could not happen on tmc2209's as well, but two people I've seen have this issue were both tmc5160's on Z (which I think is not very common). But correlation != causation.

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I think you would lose just about nothing running 2209's on Z. They don't need to move super fast or run high currents or really get any benefit from running on 48V.

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If you have the "standard size" Meanwell 24V PSU that should be all the power you need. But if the wiring between PSU and Octopus are a bit weak, maybe that's something to look at. Even if you run everything on 24V, you could still spread the load between two sets of wires and terminals ("main power" and "motor power"), with about half the stepper motors on each (set with the little power jumper next to each driver).

mortal hawk
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When you say weak, you mean loose or thin?

zinc marsh
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either one. or poorly crimped connectors. Anything to impede the happy flow of current.

waxen geyser
mortal hawk
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Crystal Cleat there could not be better example 😃

mortal hawk
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All tightly connected, wire AWG 18, are they thick enough?

zinc marsh
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Should be enough (at least for a short wire). Though I don't know what a 6-pack of 5160 working together might do in terms of current peaks.

mortal hawk
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Well anyway , I have changed to awg15, problem remains…anyway I have noticed something, it is like back part of gantry move faster than front one, in addition, if I slightly pull up a z axis in front it stays were pulled, but both back ones falls down again. Is it normal?l? Belt tension are all more or less the same

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And when I say faster is down direction, when moving up is like gantry recover leveling

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Could be a build issue?

waxen geyser
mortal hawk
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I did. Gt20 😀

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Nevertheless, I’ll recheck tomorrow…

waxen geyser
mortal hawk
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Yeap all the same

waxen geyser
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as well as checking the four pulleys, check the four idlers to make sure they're all the same too

mortal hawk
waxen geyser
# mortal hawk

any reason you have microsteps set to 16 instead of 32?

mortal hawk
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Anyway is like the front right corner slow down when getting closer to bed

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No, I thought it was like that, should I change it?

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X-y as well?

waxen geyser
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i've just noticed, you've set hold_current for all four z steppers? iirc, that's not recommended

mortal hawk
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Ok I remove them

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Removed. Really appreciated

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What’s iirc

waxen geyser
mortal hawk
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Haha. Sorry , I thought Something current related😂

waxen geyser
mortal hawk
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Mmmh , I start thinking I am stubbornly thinking all pulleys are equal, z1 motor moves much more quicker than the rest, and I replaced it recently, before start testing dynamics… smoking gun point the pulley

waxen geyser
mortal hawk
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World!

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Be noticed I am stupid! It might be 16T and for any reason I ordered 20T

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Sorry yo all of you

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Someone told me this was a good thing for reliefing PTSD but I guess it does need of a well organized head 🤪

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They will arrive tomorrow , I’ll tell you

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Thanks @waxen geyser

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You are sooooo patient

waxen geyser