Troubleshooting Y axis
Hi everyone,
Today I was trying to start a print, and when my MK2S started doing the auto-home routine at the start of the print. It didn't make it all the way to the 0 coordinate, and luckily I noticed and pressed the X button before the nozzle drilled a hole into my heatbed 😀
Here is a dramatic reenactment of the auto-home procedure, started manually from the Calibration menu: https://www.dropbox.com/s/0h63uer6cpv8epy/Auto-home%20failure.mp4?dl=0
(At the end you can see how the Y-Axis is not close enough to 0, and off-camera I'm pressing the X button to avoid drilling.)
Another video that shows the problem: https://www.dropbox.com/s/xoft6bnahqk3l57/Y%20Axis%20manual%20move%20failure.mp4?dl=0
Here I'm trying to move the Y-Axis manually through the Settings menu. As you can see, it's moving weirdly. (I don't know whether this is what you call skipping.) It's making small steps and not covering as much distance as it usually does.
Any idea what's happening and what I can do? I already checked that the Y belt is tight, and that it sits tight on both the motor wheel and the idler wheel.
Re: Troubleshooting Y axis
I'll add another point of information in case it's helpful: When moving the Y-Axis manually through the Settings option, I looked at the Y motor and it turned slowly. If I'm moving the X-Axis through Settings, I see the X motor spinning fast (i.e. normal speed.)
Re: Troubleshooting Y axis
It sounds like the locking grub screw on the pulley that attaches the gear to the stepper motor is not attached to the "flat" of the stepper motor.
Step 31 and 39: Here:
http://manual.prusa3d.com/Guide/2.+Y-axis+assembly/298
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Troubleshooting Y axis
It sounds like the locking grub screw on the pulley that attaches the gear to the stepper motor is not attached to the "flat" of the stepper motor.
Step 31 and 39: Here:
http://manual.prusa3d.com/Guide/2.+Y-axis+assembly/298
Thanks Aaron! I looked at the pulley and it seems that the screw is on the flat part, check it out:
I also tightened the two pulley screws, but the problem still remains. I'm not seeing the pulley sliding on the motor rod, it's moving in sync with it.
Any more ideas?
Re: Troubleshooting Y axis
Belt tight? Teeth on belt ok?
If the motor is moving and the bed is not, you should be able to see what is slipping...
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Troubleshooting Y axis
Belt tight? Teeth on belt ok?
If the motor is moving and the bed is not, you should be able to see what is slipping...
Seems that way to me: https://www.dropbox.com/s/1h1147d2knj05ws/2017-09-25%2014.08.07.mp4?dl=0
The belt is tight.
The bed is moving with the motor. I'm not seeing anything that's slipping. I have no idea why the movement is stuttering
Re: Troubleshooting Y axis
I did another experiment now. I disconnected the belt from the Y motor. I turned on the printer and tried moving the Y axis back and forward. (In the Settings.)
It moves forward alright, but when I try to move it backward, the motor won't move at all. (Previously when the belt was on, it would sometimes move, sometimes not, and sometimes stammer.) The number on the screen does become smaller, and get this: The screen is sometimes blinking when I'm doing the backward motion.
Any idea what's wrong and what I can do?
Re: Troubleshooting Y axis
Looking at your picture, the drive pulley seems very close to the motor body; there should be at least a 3mm gap (which means you need to move the drive pulley to the left and the whole motor assembly to the right).
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Troubleshooting Y axis
I found the problem! I did a self-test and the Y stopper was broken. Turns out one of the cables broke loose. I soldered it back on and now the printer seems to be working!
Thank you so much for your help, Aaron and PJR!