<p>For the Creality Ender 3, I had the same collision problem and after a while I found it was because of the X-axis not being level.</p>

<p>I found right hand side was more than 3-4 mm below the left side when the Z-axis height exceeds around 8-10&nbsp;cm. Below that, the two sides were even. I made some calibration by turning the eccentric nuts of the wheels and tighten them.</p>

<p>If you use Creality Ender 3, that might be the problem. Take a ruler and check between base extrusions and X-axis left/right hand sides at different Z heights.</p>

CC BY-SA 4.0
2019-06-25T23:09:14.510Z
2019-06-27T19:18:38.060Z
2019-06-27T19:18:38.060Z
she hates me
<p>The problem was twofold:</p>

<ol>
<li>Lack of bed adhesion due to the small contact surface</li>
<li>motion into the already printed objects.</li>
</ol>

<p>The <em>quick and dirty</em> way was to change two settings:</p>

<ul>
<li>Print with a small (3 mm) brim to stick the supports to the print and provide more surface. Other materials than PLA may need considerably more brim!</li>
<li>Activate Z-Hop to force the nozzle to lift over the print when traveling</li>
</ul>

<p>These tricks don't solve issues with very thin structures or in all cases. In those cases, it can be mandatory to increase the structure's (support) thickness or change the alignment.</p>

CC BY-SA 4.0
2018-10-01T18:01:05.770Z
This will help, but for thin vertical rods, the lateral force during deposition can cause bending of the structure, leading to effective random layer shift.  No way around that other than to print in a different orientation or build in a "scaffolding."
Carl Witthoft
CC BY-SA 4.0
2018-10-01T12:42:29.440Z
2019-03-06T14:49:04.863Z
2019-03-06T14:49:04.863Z
Trish
<p>When printing several objects, I recently encountered a problem that arises when the structure in itself is relatively thin or the support towers have a small surface: the printhead would in motion tend to knock one or more over as it traveled or catch at them and create layer shift.</p>

<p>How can I avoid collisions with the already printed parts of a layer?</p>

<print-quality><slicing>
How to avoid collisions with already printed objects?
Trish
# How to avoid collisions with already printed objects?

(Asked by: username_0 on 2018-10-01)

When printing several objects, I recently encountered a problem that arises when the structure in itself is relatively thin or the support towers have a small surface: the printhead would in motion tend to knock one or more over as it traveled or catch at them and create layer shift.

How can I avoid collisions with the already printed parts of a layer?

**Tags:** print-quality, slicing

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## 2 answers

### Answer by username_0 on 2018-10-01. Score: 5 | Accepted answer

The problem was twofold:

1. Lack of bed adhesion due to the small contact surface
2. motion into the already printed objects.

The *quick and dirty* way was to change two settings:

* Print with a small (3 mm) brim to stick the supports to the print and provide more surface. Other materials than PLA may need considerably more brim!
* Activate Z-Hop to force the nozzle to lift over the print when traveling

These tricks don't solve issues with very thin structures or in all cases. In those cases, it can be mandatory to increase the structure's (support) thickness or change the alignment.

> **Comments:**
> **username_2**: This will help, but for thin vertical rods, the lateral force during deposition can cause bending of the structure, leading to effective random layer shift.  No way around that other than to print in a different orientation or build in a "scaffolding."  

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### Answer by username_1 on 2019-06-25. Score: 2

For the Creality Ender 3, I had the same collision problem and after a while I found it was because of the X-axis not being level.

I found right hand side was more than 3-4 mm below the left side when the Z-axis height exceeds around 8-10 cm. Below that, the two sides were even. I made some calibration by turning the eccentric nuts of the wheels and tighten them.

If you use Creality Ender 3, that might be the problem. Take a ruler and check between base extrusions and X-axis left/right hand sides at different Z heights.


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