<p>I believe (<a href="https://gist.github.com/ellisgl/3b92a7fbca4962297bec4c906420a916" rel="nofollow noreferrer">from reference</a>) the default steps per mm for the FLSUN 3D Cube are:</p>
<pre><code>                                          X,   Y,    Z, E0 
#define DEFAULT_AXIS_STEPS_PER_UNIT   { 100, 100,  400, 150 }
</code></pre>
<p>Default marlin 2.0.x are:</p>
<pre><code>                                          X,   Y,    Z, E0 
#define DEFAULT_AXIS_STEPS_PER_UNIT   {  80,  80, 4000, 500 }
</code></pre>
<p>Such a setting would explain the excessive speeds; while the printer only needs 400 steps for advancing a single millimeter, the stepper receives 4000, this implies a tenfold, hence larger displacement and higher speeds.</p>

CC BY-SA 4.0
2020-09-28T12:51:23.513Z
2020-09-28T17:44:48.367Z
2020-09-28T17:44:48.367Z
0scar
<p>I have an FLSun 3D Cube, running off an MKS GEN V.1.4 main board. With Marlin 1.0, the Z-axis works great (and has been for three years). When I try to upgrade to Marlin 2.0, moving the Z-axis 10 mm results in extreme motion -50 mm at least, left motor then the right motor, three or four times, very fast. It's loud, it's jarring, and it's at the very least incorrect.</p>
<p>What setting am I missing?</p>

CC BY-SA 4.0
2020-09-28T05:39:25.473Z
Are you sure the steps/mm are indentical between your configurations?
Too high values for Z max speed or Z acceleration might also cause odd behaviour.
towe
CC BY-SA 4.0
2020-09-28T06:52:30.263Z
Are you using Marlin 2.0 correctly configured for your printer? If it's configured for a different printer, anything can happen. Where did you get the Marlin 2.0 image?
DoxyLover
<marlin><flsun-3d-cube><mks>
Marlin 1.0 works: Marlin 2.0 destroys Z-axis motion
Bill in Kansas City
# Marlin 1.0 works: Marlin 2.0 destroys Z-axis motion

(Asked by: username_0 on 2020-09-28)

I have an FLSun 3D Cube, running off an MKS GEN V.1.4 main board. With Marlin 1.0, the Z-axis works great (and has been for three years). When I try to upgrade to Marlin 2.0, moving the Z-axis 10 mm results in extreme motion -50 mm at least, left motor then the right motor, three or four times, very fast. It's loud, it's jarring, and it's at the very least incorrect.

What setting am I missing?

**Tags:** marlin, flsun-3d-cube, mks
> **Comments:**
> **username_1**: Are you sure the steps/mm are indentical between your configurations? Too high values for Z max speed or Z acceleration might also cause odd behaviour.  
> **username_2**: Are you using Marlin 2.0 correctly configured for your printer? If it's configured for a different printer, anything can happen. Where did you get the Marlin 2.0 image?  

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## 1 answers

### Answer by username_3 on 2020-09-28. Score: 2 | Accepted answer

I believe (from reference) the default steps per mm for the FLSUN 3D Cube are:
                                          X,   Y,    Z, E0 
#define DEFAULT_AXIS_STEPS_PER_UNIT   { 100, 100,  400, 150 }

Default marlin 2.0.x are:
                                          X,   Y,    Z, E0 
#define DEFAULT_AXIS_STEPS_PER_UNIT   {  80,  80, 4000, 500 }

Such a setting would explain the excessive speeds; while the printer only needs 400 steps for advancing a single millimeter, the stepper receives 4000, this implies a tenfold, hence larger displacement and higher speeds.


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