Help! Y-Axis Stepper Motor Skipping
Hello fellow Prusa Friends,
After months of using this printer perfectly, my y-axis stepper motor has begun to skip, causing consistent failures when the printer tries to auto bed mesh (or xyz calibration fails too). The skipping occurs when the motor is commanded to move very quickly, and I can tell it is indeed skipping because of the grinding sound that is being made. You can see video of what I'm talking about at my youtube account at:
I've confirmed that the PIDNA probe is working, the y-axis belt is tight and secure, and that I'm operating the latest firmware. I've also disconnected, cleaned, and reattached the wire connections at the Rambo board but to no avail. I've successfully commanded the y axis motor to move both directions via the settings>adjust axis menu, so I know the motor itself is working.
Can anybody please help me? I'm at a loss for what to do.
I got the i3 Mk2S kit back last June, so the components are all less than 1 year old, and should thus be covered by warranty. Is there a way that customer support can send me a new Rambo 1.3 driver card?
Thank you anyone for the help!
Re: Help! Y-Axis Stepper Motor Skipping
Make sure your printer is running in High Power mode and make a proper x,y,z-calibration. Your printer doesn't find a point in the 2nd row but by the sound in the Video I could not say whether this ist because the motor skips. Could also be that the calibration got messed up after moving the printer. Furthermore you should carefully check your y-axis, bed and rods. I would bet your bed gets stuck at certain positions.
Re: Help! Y-Axis Stepper Motor Skipping
Thanks for the advice on running at High Power mode Alexander, I'll try that tomorrow morning. Though, I don't think the machine should be required to operate at such a state, and limiting my operations to only high power is a band aid fix.
I'll also detach the bed from the belt and try moving it across the rods to see if there are any sticky spots.
Per the calibration, I've been able to get a perfect score on the xyz calibration when it doesn't fail due to the y axis skipping. I'll try to get a better video of the grinding noise in order to prove that that is indeed occurring.
Thanks!
Re: Help! Y-Axis Stepper Motor Skipping
Thanks for the advice on running at High Power mode Alexander, I'll try that tomorrow morning. Though, I don't think the machine should be required to operate at such a state, and limiting my operations to only high power is a band aid fix.
I'll also detach the bed from the belt and try moving it across the rods to see if there are any sticky spots.
Per the calibration, I've been able to get a perfect score on the xyz calibration when it doesn't fail due to the y axis skipping. I'll try to get a better video of the grinding noise in order to prove that that is indeed occurring.
Thanks!
Just one more thought...
I remember some post where people got some filament pieces and strings (for whatever reason) to the y-axis motor pulley which
caused some similar effect to yours.
https://shop.prusa3d.com/forum/original-prusa-i3-mk2-f23/xyz-calibration-failure-with-new-firmware-t6859-s10.html
Re: Help! Y-Axis Stepper Motor Skipping
Hey Alex,
So I've confirmed that the gear head on the motor is tightened (and its screw is secure against the flat part of the motor shaft), and that there is no dirt in the pulley or gear head of the motor. I've also turned on "High Power" mode, but all of this is to no avail.
I went ahead and switched the x and y motors, making sure to keep their wiring correct, and as can be seen in the video below, the "grinding failure of the "y axis" motor is still present.
I can also assure you that the y axis belt is perfectly secure, not loose, and is if anything good and tight.
This is pretty damning evidence that the y axis driver has failed.
Any ideas?
Re: Help! Y-Axis Stepper Motor Skipping
Okay! So I got my printer running smoothly again, and have had it running for the past few days to make sure.
The problem was... the y axis bearings! I've been running my printer for months in a hot enclosure, and it must've dried all the lubrication out of it. I used some machine oil on all of the linear sliders, especially the y axis ones, and now my Prusa is working just like normal!
BTW, after doing extensive research on the drivers on the mini Rambo 1.3, they are "guaranteed" to never fail, because the PCB is rated to insanely high temperatures.