<p>Hmmmm In my experience when a printer has that bad of wobble it is still the Z axis. Your rods might be good, but are the two Z axis the <em>exact</em> correct distance and equal distance on the printer frame? Imagine that you had one a few millimeters too far out. How might the rods act? Mayhaps, over the course of several layers, they would slowly drift back and forth? Creating a period effect on your print? What do the top of the rods do over time? Do they move a lot if you go from height 0 to 100mm on z?</p>
<p>I have a few ideas. What happens if you loosen you Z motors so they can move around their mount? I had to do that on my Prusa back in the day. I think for that machine the Belt was actually too tight causing the issue. Current printers are usually better designed so its unlikely that is your issue. Also measure the distance between the top of the rods when the carriage is at 0, and at max. You should see very little variance.</p>
<p>If it was on both sides I would say it was bad PID calibration. <a href="https://www.simplify3d.com/support/print-quality-troubleshooting/#lines-on-the-side-of-print" rel="nofollow noreferrer">IE this simplify 3d link</a></p>
<p>Though you can see on this forum the fellow <a href="https://www.3dhubs.com/talk/thread/z-axis-artifacts-wobbling-irregularities-waves-ribbing" rel="nofollow noreferrer">had a bad coupler.</a> So still mechanical.</p>
<p>Also could be back lash / belt lash.. but unlikely</p>

CC BY-SA 3.0
2017-01-09T15:06:44.013Z
+1 hit most of the points I was about to comment for. Any idea if the machine uses a worm gear or some sort of nut? Is it possible that a nut would not be concentric or be cross-threaded?
tbm0115
CC BY-SA 3.0
2017-01-09T15:52:45.380Z
Thanks @tbm0115! Yes photos of the machine would likely help as well.
MakerModder
CC BY-SA 3.0
2017-01-10T05:40:34.163Z
hey thanks it was the z axis coupling, just had to readjust it, thank you so much.
blah42
CC BY-SA 3.0
2017-01-09T04:42:01.220Z
2017-01-09T21:42:32.780Z
2020-06-18T08:29:41.667Z
MakerModder
<p>The right side of my prints always have the standard ribbing effect given by a bent z rod, however I have replaced the rod and there was no change. Here are pictures of one of my more recent prints:
<a href="https://i.sstatic.net/Sucjy.jpg" rel="noreferrer"><img src="https://i.sstatic.net/Sucjy.jpg" alt=""></a>
and the left side of that same print:
<a href="https://i.sstatic.net/29xDN.jpg" rel="noreferrer"><img src="https://i.sstatic.net/29xDN.jpg" alt=""></a>
As you can see the left is almost unaffected the right is the only side with the error. Anyone have any ideas about this?</p>

CC BY-SA 3.0
2017-01-09T13:59:48.310Z
Looks like your axes still aren't quite aligned properly. What speed is your extruder moving at when doing shells?
Diesel
<print-quality><prusa-i3><z-axis>
3d prints come up with ribbing on one side
blah42
# 3d prints come up with ribbing on one side

(Asked by: username_0 on 2017-01-09)

The right side of my prints always have the standard ribbing effect given by a bent z rod, however I have replaced the rod and there was no change. Here are pictures of one of my more recent prints:
[![](https://i.sstatic.net/Sucjy.jpg)](https://i.sstatic.net/Sucjy.jpg)
and the left side of that same print:
[![](https://i.sstatic.net/29xDN.jpg)](https://i.sstatic.net/29xDN.jpg)
As you can see the left is almost unaffected the right is the only side with the error. Anyone have any ideas about this?

**Tags:** print-quality, prusa-i3, z-axis

> **Comments:**
> **username_1**: Looks like your axes still aren't quite aligned properly. What speed is your extruder moving at when doing shells?  

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## 1 answers

### Answer by username_2 on 2017-01-09. Score: 6 | Accepted answer

Hmmmm In my experience when a printer has that bad of wobble it is still the Z axis. Your rods might be good, but are the two Z axis the *exact* correct distance and equal distance on the printer frame? Imagine that you had one a few millimeters too far out. How might the rods act? Mayhaps, over the course of several layers, they would slowly drift back and forth? Creating a period effect on your print? What do the top of the rods do over time? Do they move a lot if you go from height 0 to 100mm on z?

I have a few ideas. What happens if you loosen you Z motors so they can move around their mount? I had to do that on my Prusa back in the day. I think for that machine the Belt was actually too tight causing the issue. Current printers are usually better designed so its unlikely that is your issue. Also measure the distance between the top of the rods when the carriage is at 0, and at max. You should see very little variance.

If it was on both sides I would say it was bad PID calibration. [IE this simplify 3d link](https://www.simplify3d.com/support/print-quality-troubleshooting/#lines-on-the-side-of-print)

Though you can see on this forum the fellow [had a bad coupler.](https://www.3dhubs.com/talk/thread/z-axis-artifacts-wobbling-irregularities-waves-ribbing) So still mechanical.

Also could be back lash / belt lash.. but unlikely

> **Comments:**
> **username_3**: +1 hit most of the points I was about to comment for. Any idea if the machine uses a worm gear or some sort of nut? Is it possible that a nut would not be concentric or be cross-threaded?  
> **username_2**: Thanks @username_3! Yes photos of the machine would likely help as well.  
> **username_0**: hey thanks it was the z axis coupling, just had to readjust it, thank you so much.  

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