Y-Axis SelfTerst failure suddenly
Hi there. Purchased a new MK3S factory assembled for Christmas last year. I had been printing with my MK3s for a few months with no issue. Recently I tried to print and got a scary noise in the middle of printing and it started complaining of a y-axis length failure. I reset the machine and tried running through the calibration wizard, which now fails on Y-Axis Length.
I’ve scanned the forums here but frankly all the responses on this issue are pretty complicated and seem to involve tearing the thing apart - is there a way to get someone on the phone to walk through troubleshooting this issue?
Can you test if the Y-axis/the print bed is moving freely without resistance?
You can shut off motors in the menu or switch the printer off.
With the printer unplugged, I can move the print bed freely. I've looked below the printer and I can't see anything obstructing the movement.
The movement isn't 'smooth as silk' - I have to exert force to move the bed and in some parts of travel it moves easily and in others it's a little harder. I can't tell if that is the motor or something with the bed.
Also I notice that when I manually move the bed, the LCD screen flickers white. Not sure if that's supposed to happen.
Screen flickering ist perfectly normal, the motor generates current when moved.
You should now find out the cause of the resistance in movement. There are a lot of possibilities, please check the U-bolts which move very near the machine body, the bearings, belt tension, motor, motor-pulley and pulley on the opposite side of belt, to begin with 😉
Here is a video showing the tray movement. It does not feel like it is hitting anything, it feels like the motor itself suddenly 'seizes' as you move the tray. Where it grabs isn't consistent so again making me think it's not an obstruction. [video width="1280" height="720" mp4="https://forum.prusaprinters.org/wp-content/uploads/2020/09/PrusaTray_Trim2.mp4"][/video]
I guess one or more defective linear bearings. I had this problem and for this reason I printed other bearing holders and installed brass slide bearings.
I'm getting this same error as well. When I move the Y axis, the stepper seizes up when current is being generated from the motion. If I remove the belt, the axis slides freely and without problems. I also bought a new Y axis stepper and it's having the same issue. Is this a board issue?? Firmware??
Try removing the Y-axis motor connector from the Einsy Board and then manually move the printing bed back and forth. If everything goes right, it is possible that the Einsy has been damaged. You can try to change the axes ( X -> Y ) and see how it behaves. If the X-axis causes problems then you are already one step ahead. I would then contact the Prusa Chat.