<p>Apparently, the possible cause mentioned by @R.. GitHub STOP HELPING ICE turned out to be true. The frame was noticeably skewed in the Y-axis, which is why the prints were leaning in that direction.</p>
<p>I replaced the <a href="https://www.prusa3d.com/prusa-i3-printable-parts/" rel="nofollow noreferrer">Z-axis top parts</a> with a 3D printed modified version of them (what came with the printer is orange, what I printed is yellow.) The modified version is slightly longer so as to move the steel rods (ones that hold the X-axis) slightly towards the front of the printer (in the opposite direction to the skew)</p>
<p>This turned out to work perfectly, the skew is still slightly present, but it has been substantially mitigated and I can fix it completely by adjusting the length of the printed parts.</p>
<p><a href="https://i.sstatic.net/r6Aii.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/r6Aii.png" alt="enter image description here" /></a></p>
<p><a href="https://i.sstatic.net/c7Fev.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/c7Fev.png" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2020-11-18T15:37:31.570Z
Any clue as to why the skew occurred?
BobT
CC BY-SA 4.0
2020-11-19T16:38:21.753Z
@BobT Well, skewed prints are the effect of a skewed frame but I have no idea as to what caused this. Sorry to disappoint. Anyway, I'm glad that it's working now.
StLuke5
CC BY-SA 4.0
2020-11-01T18:30:30.270Z
2020-11-01T18:30:30.270Z
StLuke5
<p>My prints have recently started to come out with a serious skew along the Y axis.  This occurs regardless of printing parameters such as speed/acceleration. I don't know the exact cause yet, can someone help me resolve this? What could have caused this?</p>
<p><a href="https://i.sstatic.net/XiodQ.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/XiodQ.png" alt="enter image description here" /></a></p>
<p>Please don't mind the stringing/blobs, I'm currently running out of filament and I was forced to use an old PET-G spool damaged by moisture.</p>

CC BY-SA 4.0
2020-10-31T22:53:15.400Z
looks like you loose steps in Y. Is the belt tight?
Trish
CC BY-SA 4.0
2020-11-01T01:51:48.763Z
I can't think of a plausible theory whereby lost steps would be a consistent skew like that. It looks to me more like the frame isn't square.
R.. GitHub STOP HELPING ICE
CC BY-SA 4.0
2020-11-01T10:57:47.970Z
I ran the selftest and actually, the Y-belt is overtightened. Even if this does not change anything, I need to fix it. I'm pretty sure there is something wrong with the frame, perhaps it actually isn't square (I can tell this just by looking at the printer.). I have no idea how this happened as I haven't used this machine for a long time.
StLuke5
<print-quality><prusa-i3>
Prusa MK3S Y-skewed prints
StLuke5
# Prusa MK3S Y-skewed prints

(Asked by: username_0 on 2020-10-31)

My prints have recently started to come out with a serious skew along the Y axis. This occurs regardless of printing parameters such as speed/acceleration. I don't know the exact cause yet, can someone help me resolve this? What could have caused this?

[![enter image description here](https://i.sstatic.net/XiodQ.png)](https://i.sstatic.net/XiodQ.png)

Please don't mind the stringing/blobs, I'm currently running out of filament and I was forced to use an old PET-G spool damaged by moisture.

**Tags:** print-quality, prusa-i3
> **Comments:**
> **username_1**: looks like you loose steps in Y. Is the belt tight?  
> **username_2**: I can't think of a plausible theory whereby lost steps would be a consistent skew like that. It looks to me more like the frame isn't square.  
> **username_0**: I ran the selftest and actually, the Y-belt is overtightened. Even if this does not change anything, I need to fix it. I'm pretty sure there is something wrong with the frame, perhaps it actually isn't square (I can tell this just by looking at the printer.). I have no idea how this happened as I haven't used this machine for a long time.  

---

## 1 answers

### Answer by username_0 on 2020-11-01. Score: 1 | Accepted answer

Apparently, the possible cause mentioned by @R.. GitHub STOP HELPING ICE turned out to be true. The frame was noticeably skewed in the Y-axis, which is why the prints were leaning in that direction.

I replaced the [Z-axis top parts](https://www.prusa3d.com/prusa-i3-printable-parts/) with a 3D printed modified version of them (what came with the printer is orange, what I printed is yellow.) The modified version is slightly longer so as to move the steel rods (ones that hold the X-axis) slightly towards the front of the printer (in the opposite direction to the skew)

This turned out to work perfectly, the skew is still slightly present, but it has been substantially mitigated and I can fix it completely by adjusting the length of the printed parts.

[![enter image description here](https://i.sstatic.net/r6Aii.png)](https://i.sstatic.net/r6Aii.png)

[![enter image description here](https://i.sstatic.net/c7Fev.png)](https://i.sstatic.net/c7Fev.png)

> **Comments:**
> **username_3**: Any clue as to why the skew occurred?  
> **username_0**: @BobT Well, skewed prints are the effect of a skewed frame but I have no idea as to what caused this. Sorry to disappoint. Anyway, I'm glad that it's working now.  

---

