Axis length error (Y axis) after initial build
hello,
During the self test, I get the following error string:
'Selftest error
Please check :
Axis length
Axis Y'
when it is moving the plate along the Y axis, I hear a clacking sound when it reaches the end.
Is this a tension on the belt issue?
The odd thing is when I ran this self test the first time, it got past this step and completed. I wanted to adjust the height of the extruder from the bed and this started occurring when I re-ran the self test.
RE: Axis length error (Y axis) after initial build
Most likely this is the carriage hitting something issue.
Check all your zip ties (popular culprit) and cables.
RE: Axis length error (Y axis) after initial build
hmm I do not think the zipties are impeding movement.
what should tell the bed that it has reached the end? it appears like one of the left side cylinders is hitting the end of the rail (80mb each video, one from each side) and it wants to keep going (the second video)
RE: Axis length error (Y axis) after initial build
Good video. I don't have a clue...
Prusa moves the bed to the rear until it hits the back rail. That sets the endpoint; 220mm or whatever.
It then moves back to zero in the forward direction - and is not supposed to hit anything...
Watch the travel to the rear and make sure the carriage goes all the way.
All I can think of is that something is stopping it short, so when it subtracts the 220mm from current location it is way overshooting home.
RE: Axis length error (Y axis) after initial build
The left side bearings hit the rod holders - this sets Y-axis range. The printer determines the X and Y stopping points by monitoring the motor drive currents and detecting a stall condition.
RE: Axis length error (Y axis) after initial build
I had the same problem after the initial build (on monday). In my case the solution was to reduce the tension of the tooth belt (step by step). I think this increases the lenght of the belt to the steps, the motor needs for the needed length.
RE: Axis length error (Y axis) after initial build
Hi,
Just finished mounting my Prusa Kit and I have the same problem presented on the video.
Any ideas how to solve?
Thanks,
MD
RE: Axis length error (Y axis) after initial build
One thing about Gates belts - they don't stretch.
Whatever else is going on, you can't make the belt longer with tension.
RE: Axis length error (Y axis) after initial build
Probably the printer is not happy with the Y length.
When hearing the clacking sound is the bed really reaching the end as tim described? There is no endstop switch when hitting the rod holders the motor current is increasing as tim mentioned this is the detection.
The number of the step motor steps from start to end of the Y axis the printer is calculating it's length. If this is not the expected length 220mm it starts to complain.
even an old man can learn new things 🙂
Standard I3 mk3s, MMU2S, Prusa Enclosure, Fusion 360, PrusaSlicer, Windows 10
PRUSA MINI+ Prusalink + Prusa Connect
RE: Axis length error (Y axis) after initial build
Well to make it more challenging - it won't complain at the back end - where the problem is.
It will complain when it tries to go back to the front, 220mm away from the incorrect origin.
Figure out what is stopping the carriage from going all the way to the rear.
RE: Axis length error (Y axis) after initial build
Generally it's U-bolts compressing the bearings causing them to seize along the path of travel. U-bolts need to be snug, not tight. Bearings aligned in the middle of the slots, and almost able to wiggle.
Recently there's also been an increase if folks planning to use an enclosure that install a different Y-bed cable cover that bends the wire so it interferes with the X cable harness, and locks things up when it snags.