<p>I don't understand the reasoning behind a first layer having a different offset from the following layers, but, You can manually add a re-definition of the current height after the first layer, suppose your first layer is 0.2 mm, you just need to tell the printer to move to a slightly higher next layer to redefine this as a different Z-offset.</p>
<ul>
<li>From a G-code file find the start of the second layer:<br><code>G0 F600 X141.541 Y109.467 Z0.37</code></li>
<li>Modify this to:<br><code>G0 F600 X141.541 Y109.467 Z0.42</code></li>
<li>Now insert the following command:<br><code>G92 Z0.37</code></li>
</ul>
<p>Now it is like you have changed the Z-offset.</p>
<p>The reason for not using <code>M206</code> is that is applied onto current offsets, if you accidentally save setting to memory after printing, it stores this offset. You can use <code>M206</code>, but use it carefully. A re-definition of the Z level is never stored, the next <code>G28</code> erases the effect, so does repowering the motors.</p>

CC BY-SA 4.0
2021-04-03T09:52:21.983Z
Hm I cannot find `G0` in PrusaSlicer printer settings G-code. Mine goes `M420` than `G1 Z2 F240..` Also is this just changing the layer heigh or actual Z offset ? I just found out about `M206` documentation says it can set the Z offset for the first layer but what is used after the setting on the printer or ?
Sterling Duchess
CC BY-SA 4.0
2021-04-03T13:46:21.153Z
@SterlingDuchess `G1` is identical to `G0` for e.g. Marlin and RepRap firmware. I wouldn't recommend using `M206`.
0scar
CC BY-SA 4.0
2021-04-03T09:43:23.230Z
2024-12-21T06:53:10.107Z
2024-12-21T06:53:10.107Z
0scar
<p>Trying to change the Z level (NOT the offset) during a print isn't a good idea UNLESS you know that all future moves will be &quot;relative&quot;.</p>
<p>The <code>M206</code> (if you use Marlin) is the right way to set it!  Depending on the slicer, just create TWO &quot;different&quot; printer definitions and add them to the startup G-codes.</p>
<p>If you don't save it, a reset will return the z-offset to the &quot;saved&quot; value. Or consider resetting to a &quot;standard&quot; value in the ending G-code.</p>
<p>Also, consider using &quot;baby-stepping&quot; (if you can), and manually adjusting things at the start of a print with a different surface.</p>

CC BY-SA 4.0
2021-04-04T03:14:18.250Z
Welcome to 3D Printing SE and thank you for your contribution. When you get a chance, please take the [Tour](https://3dprinting.stackexchange.com/tour) to understand how the site works and how it is different than others.
agarza
CC BY-SA 4.0
2021-04-03T23:25:30.377Z
2021-04-04T15:37:09.507Z
2021-04-04T15:37:09.507Z
Scott Baeder
<p>In slicer G-code is it possible to set the probe Z offset for the first layer only?</p>
<p>For my stock E3 plate I find -4.125 mm best however for glass I need to go to -4.175 mm for the first layer to get better adhesion. So it's a manual process every time. Any way to tell the slicer do the first layer at -4.175 mm and next ones at -4.125 mm?</p>

CC BY-SA 4.0
2021-04-07T17:48:03.077Z
Are you running stock firmware/Marlin firmware?
0scar
CC BY-SA 4.0
2021-04-08T14:30:36.607Z
TH3D firmware, latest version.
Sterling Duchess
<creality-ender-3><g-code><bltouch><z-probe>
First layer Z-offset in G-code
Sterling Duchess
# First layer Z-offset in G-code

(Asked by: username_0 on 2021-04-03)

In slicer G-code is it possible to set the probe Z offset for the first layer only?

For my stock E3 plate I find -4.125 mm best however for glass I need to go to -4.175 mm for the first layer to get better adhesion. So it's a manual process every time. Any way to tell the slicer do the first layer at -4.175 mm and next ones at -4.125 mm?

**Tags:** creality-ender-3, g-code, bltouch, z-probe

> **Comments:**
> **username_1**: Are you running stock firmware/Marlin firmware?  
> **username_0**: TH3D firmware, latest version.  

---

## 2 answers

### Answer by username_1 on 2021-04-03. Score: 4 | Accepted answer

I don't understand the reasoning behind a first layer having a different offset from the following layers, but, You can manually add a re-definition of the current height after the first layer, suppose your first layer is 0.2 mm, you just need to tell the printer to move to a slightly higher next layer to redefine this as a different Z-offset.

* From a G-code file find the start of the second layer:  
  `G0 F600 X141.541 Y109.467 Z0.37`
* Modify this to:  
  `G0 F600 X141.541 Y109.467 Z0.42`
* Now insert the following command:  
  `G92 Z0.37`

Now it is like you have changed the Z-offset.

The reason for not using `M206` is that is applied onto current offsets, if you accidentally save setting to memory after printing, it stores this offset. You can use `M206`, but use it carefully. A re-definition of the Z level is never stored, the next `G28` erases the effect, so does repowering the motors.

> **Comments:**
> **username_0**: Hm I cannot find `G0` in PrusaSlicer printer settings G-code. Mine goes `M420` than `G1 Z2 F240..` Also is this just changing the layer heigh or actual Z offset ? I just found out about `M206` documentation says it can set the Z offset for the first layer but what is used after the setting on the printer or ?  
> **username_1**: @username_0 `G1` is identical to `G0` for e.g. Marlin and RepRap firmware. I wouldn't recommend using `M206`.  

---

### Answer by username_2 on 2021-04-03. Score: 2

Trying to change the Z level (NOT the offset) during a print isn't a good idea UNLESS you know that all future moves will be "relative".

The `M206` (if you use Marlin) is the right way to set it! Depending on the slicer, just create TWO "different" printer definitions and add them to the startup G-codes.

If you don't save it, a reset will return the z-offset to the "saved" value. Or consider resetting to a "standard" value in the ending G-code.

Also, consider using "baby-stepping" (if you can), and manually adjusting things at the start of a print with a different surface.

> **Comments:**
> **username_3**: Welcome to 3D Printing SE and thank you for your contribution. When you get a chance, please take the [Tour](https://3dprinting.stackexchange.com/tour) to understand how the site works and how it is different than others.  

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