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Y-axis fails  

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Jani
 Jani
(@jani)
Member
Y-axis fails

Hello,

I assembled a Prusa MK4 but the self-test of the y-axis fails, see video.
I know that the misplacement of the bearings is a common issue. I don't see an issue, I have already redid the assembly of the y-carriage.
But it still doesn't work, maybe I misunderstood the instructions.

Can someone confirm that those bearings are misplaced, see photo? I hope it's visible from that angle.


https://storage.googleapis.com/prusa3d-content-prod-14e8-wordpress-forum-prod/2023/11/90000881-y-axis-test-fail.mp4

Thank you in advance, and greetings from Belgium!

Jani

This topic was modified 5 months ago 2 times by Jani
Posted : 26/11/2023 12:48 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Y-axis fails

Hi Jani, 

Are the bearings central in the holders or are they offset slightly towards each other? 

i don't know if that would cause an error, but it would make the Y axis appear longer than it should be. 

regards joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 27/11/2023 1:20 pm
Zappes
(@zappes)
Reputable Member
RE: Y-axis fails

I had the very same issue, disassembled half of my (factory-assembled) MK4, found absolutely no issues and was close to crying. Reverted to firmware 5.0.0, all calibrations worked perfectly and now my printer is in top shape again.

This is very probably not your fault but a bug in the 5.1.0 firmware.

My models on Printables
Posted : 27/11/2023 1:29 pm
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DrNick
(@drnick)
Active Member
RE: Y-axis fails

Mine looked exactly the same.

What did help was the suggestion from LilyPink. Just put the end of a tweezer to the point were the bearing would hit the front, so that it doesn't go all the way to the front. Worked fine for me.

 

https://forum.prusa3d.com/forum/english-forum-original-prusa-i3-mk4-hardware-firmware-and-software-help/y-and-z-self-test-failure-after-update-to-5-1-0/#post-686550

Posted : 28/11/2023 4:19 pm
MaBaTaBa
(@mabataba)
Member
RE: Y-axis fails

Hello,

the same error almost drove me to despair with my self-assembled MK4.

The solution: tightend the y-belt significantly more than expected (then the belt tuner will also work more reliably and fits perfectly). 

For quick adjustment of the y-belt tension https://www.printables.com/de/model/575521-simple-prusa-i3-mk4-y-axis-belt-tensioner-3-mm-and works perfectly.

Greetings Maik

 

 

Posted : 28/11/2023 8:36 pm
Tyler Dola
(@tyler-dola)
Active Member
RE:

 

Posted by: @zappes

I had the very same issue, disassembled half of my (factory-assembled) MK4, found absolutely no issues and was close to crying. Reverted to firmware 5.0.0, all calibrations worked perfectly and now my printer is in top shape again.

This is very probably not your fault but a bug in the 5.1.0 firmware.

Agreed... I had to do the same thing. My axis passed on firmware 5.0.1... and the Y fails on 5.1.0... I did a factory reset with a 5.0.1 firmware file to downgrade, completed the calibration/tests, then upgraded to 5.1.0... Prints beautifully!

This post was modified 5 months ago by Tyler Dola
Posted : 29/11/2023 5:46 pm
Zappes liked
Tipler
(@tipler)
Member
RE:

Had the exact same problem right now. Y axis fails on 5.1.0 but after downgrading to 5.0.0 it succeeds. That indicates a problem with firmware itself.

It's not just 5.1.0 I have problems with. The 5.0.1 was also buggy (my screen would flicker and appear as if it had a loose connection) as is the 5.0.0 but I managed to find a workaround for my problems with 5.0.0's Z axis calibration failures.

I have had 2 bad experiences in a row with firmware updates and I will keep my 5.0.0 until something changes with the way these firmwares are released/tested. No idea what is the reason behind these buggy firmwares. Are there not enough people testing the alpha/beta firmware's or the testing itself is lacking?

This post was modified 5 months ago by Tipler
Posted : 01/12/2023 11:07 am
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brescoli
(@brescoli)
Member
RE: Y-axis fails

I had the same problem that the Y axis test was systematically failing, independently of the belt tension or the positioning of the bearings. I had trouble shoot the problem and the root cause was that I had installed wrongly the Y-Belt tensioners (step 29) of the Y-Axes assembly instructions. I had installed the one that goes left in the right position and the left one in the right position. I had re-installed the Y-belt tensioners in the right position and the problem of Y axis fail is solved. Now it always passes the test. 

Posted : 03/12/2023 12:11 pm
Neverdie156
(@neverdie156)
Member
RE: Y-axis fails

I had same problem. My solution was increase belt tension. When I testing tension in app, I have info that the belt is too tight, but the test comes out OK

Posted : 10/12/2023 1:35 pm
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