Y-Axis test - false negatives !?
Hello Community,
I am requesting assistance regarding a persistent "Failed Y-Axis test" error on my new CoreOne+. Despite this error, the printer actually performs extremely well with high precision and excellent print quality. However, I am unable to clear the calibration wizard and the persistent warning is blocking normal operation.
Machine Status:
Model: Prusa CoreOne+
FW: 6.4.0+11974
Troubleshooting Steps Already Performed:I have strictly followed the official guides and forum advice, verifying the following points:
Belt Tension: Tuned exactly to the recommended frequency (Hz) using the web tool.
Interference Check: Verified the side filament sensor cable; it is properly tucked and does not touch or hinder movement at the back.
Maintenance: Rods and bearings are greased and smooth.
Gantry Alignment: Visually confirmed that both Y-carriages hit the front hard stops simultaneously (gantry is square).
Reset: Performed a full Factory Reset (Hard Reset) followed by a fresh calibration attempt.
The Y-axis moves smoothly, homing seems physically correct, but the software throws the "Failed" in Y-axis.I have attached a video showing the movement behavior.
But I don't know what I search...
Is there a way to force-mark the self-test as "Passed" via G-code or a hidden menu, given that the machine physical performance is flawless?
Are there any known issues with the CoreOne+ specifically regarding false negatives in Y-calibration?
Thank you for your technical insight.
Best Answer by hyiger:
I'm not 100% sure I understand the exact manipulations to achieve this without touching/tensioning the belts at all, do I need to manually twist/adjust the gantry frame itself to make it square mechanically? I'll tinker with it again following your link precisely.
You should never use the belts to square the gantry. It must be adjusted by manually bending the brackets that attach the gantry to the Y-axis bearing holders. For example, if the right side has a gap then wedge something on the left side and push on the right side until it is square. Then when re-tensioning the belts both left and right screws must be turned by exactly the same amount in the same direction. If you adjust independently of each other it is quite possible to pull the gantry out of alignment again.
RE: Y-Axis test - false negatives !?
Gantry Alignment: Visually confirmed that both Y-carriages hit the front hard stops simultaneously (gantry is square).
When you are checking gantry alignment, are you doing so with the belts completely slack? First completely loosen the belts, then check alignment. Follow this guide: Adjusting belt tension especially the section on quick gantry alignment.
RE: Y-Axis test - false negatives !?
Strange -- maybe there is something else going on which we are unaware of? There is currently another thread in the General section, and yet another in the German Core One forum, about stubborn problems with the Y axis test.
RE: Y-Axis test - false negatives !?
Thanks for your quick reply, @hyiger.
I'm a bit lost on where to start over, but why not reset everything.
To confirm:
with belts completely slack, we need the gantry to naturally align square (both sides touching front stops simultaneously without belts pulling), correct? Then tension per the guide.
I'm not 100% sure I understand the exact manipulations to achieve this without touching/tensioning the belts at all, do I need to manually twist/adjust the gantry frame itself to make it square mechanically? I'll tinker with it again following your link precisely.
Appreciate the guidance!
RE: Y-Axis test - false negatives !?
I'm not 100% sure I understand the exact manipulations to achieve this without touching/tensioning the belts at all, do I need to manually twist/adjust the gantry frame itself to make it square mechanically? I'll tinker with it again following your link precisely.
You should never use the belts to square the gantry. It must be adjusted by manually bending the brackets that attach the gantry to the Y-axis bearing holders. For example, if the right side has a gap then wedge something on the left side and push on the right side until it is square. Then when re-tensioning the belts both left and right screws must be turned by exactly the same amount in the same direction. If you adjust independently of each other it is quite possible to pull the gantry out of alignment again.
RE: Y-Axis test - false negatives !?
You should never use the belts to square the gantry. It must be adjusted by manually bending the brackets that attach the gantry to the Y-axis bearing holders. For example, if the right side has a gap then wedge something on the left side and push on the right side until it is square. Then when re-tensioning the belts both left and right screws must be turned by exactly the same amount in the same direction. If you adjust independently of each other it is quite possible to pull the gantry out of alignment again.
Thank you very much. That was it, we redid everything and by bending the sheet metal we corrected the 5mm gap. We were then able to finish the self-test...However, I feel like it's not printing as well (slight stringing) 🙂 But one thing at a time.
RE: Y-Axis test - false negatives !?
However, I feel like it's not printing as well (slight stringing) 🙂 But one thing at a time.
Stringing can be caused by the filament not being dry or perhaps the nozzle temperature is too high. Try drying the filament first.