<p>Assuming that the model is sliced correctly, not scaled (by looking into the G-code you can find out if it is sliced correctly, look up the last layer move <code>G1 Zxx.xx</code>, <code>xx.xx</code> should be the height of the model). If that is correct, then your Z might have a problem in that the steps per mm are set incorrectly, or your Z stepper is missing steps.</p>
<p>As Marlin is used as printer firmware, you can check and change the configuration of the Z steps per mm. When using <a href="https://3dprinting.stackexchange.com/questions/10573/what-is-a-printer-console-terminal">a console</a> you are able to communicate with the printer and see output return.</p>
<p>With G-code <a href="https://reprap.org/wiki/G-code#M92:_Set_axis_steps_per_unit" rel="nofollow noreferrer"><code>M92</code></a> you get a report of the current settings. These should be verified with the mechanics (e.g. gearing) and electronics used (e.g. micro stepping value).</p>
<p>In firmware configuration this is found in file Configuration.h (<em>note: this is an <strong>example</strong> and may differ from your values!</em>):</p>
<pre><code>/**
 * Default Axis Steps Per Unit (steps/mm)
 * Override with M92
 *                                      X, Y, Z, E0 [, E1[, E2...]]
 */
#define DEFAULT_AXIS_STEPS_PER_UNIT   { 80, 80, 4000, 500 }
</code></pre>
<p>The third value is the setting for the Z axis. Your value is too low and should be increased according to the fore mentioned mechanics and electronics.</p>
<p>By sending the command <code>M92 Zxxx</code> (where xxx denotes the value you calculated) will update the steps per mm.</p>
<p>There are <a href="https://blog.prusaprinters.org/calculator_3416/" rel="nofollow noreferrer">online calculators</a> that can help you calculate the correct value.</p>
<p>As an example, a very common lead screw is the trapezoid Tr8x8(p2). Assuming that you have normal 200 steps/rev steppers and use 16 micro steps and have the fore mentioned lead screws with a 2 mm pitch, the Z requires 1600 steps per mm.</p>
<p>You should check your hardware, stepper, screw and driver. Note that 8000 is a strange value, your Z axis is only about 10 % off, if 8000 value is correct for 200 (1.8°), 1/32, 0.8 pitch, but also for 400 (0.9°), 1/16, 0.8 pitch (M5).</p>
<p>Considering you are losing about 10 % it can also be that the Z stepper is missing some steps. Increasing the Vref of the stepper motor drivers may help with that.</p>

CC BY-SA 4.0
2021-01-05T09:44:49.200Z
2021-01-07T15:55:08.963Z
2021-01-07T15:55:08.963Z
0scar
<p>When printing the Z-axis appears out of scale. I'm using a self-built 3D printer.</p>
<p>For example:</p>
<ul>
<li>When printing a 10x10x10 mm cube, the Z height is 9.01 mm;</li>
<li>When printing a 20x20x20 mm cube, the Z height is 18.6 mm.</li>
</ul>
<p>Does anyone know a possible cause of this problem?</p>
<hr />
<p><em>I checked the G-code and everything is sliced correctly.</em><br>
<em>I have now tried connecting a computer to the printer via usb and I executed the command <code>M92</code>. The response I got was this: <code>M92 X200 Y200 Z8000 E500</code>.</em></p>

<z-axis><layer-height>
Z-axis scale wrong
Xander Suys
# Z-axis scale wrong

(Asked by: username_0 on 2021-01-05)

When printing the Z-axis appears out of scale. I'm using a self-built 3D printer.

For example:

* When printing a 10x10x10 mm cube, the Z height is 9.01 mm;
* When printing a 20x20x20 mm cube, the Z height is 18.6 mm.

Does anyone know a possible cause of this problem?

---

*I checked the G-code and everything is sliced correctly.*  
*I have now tried connecting a computer to the printer via usb and I executed the command `M92`. The response I got was this: `M92 X200 Y200 Z8000 E500`.*

**Tags:** z-axis, layer-height


---

## 1 answers

### Answer by username_1 on 2021-01-05. Score: 1

Assuming that the model is sliced correctly, not scaled (by looking into the G-code you can find out if it is sliced correctly, look up the last layer move `G1 Zxx.xx`, `xx.xx` should be the height of the model). If that is correct, then your Z might have a problem in that the steps per mm are set incorrectly, or your Z stepper is missing steps.

As Marlin is used as printer firmware, you can check and change the configuration of the Z steps per mm. When using [a console](https://3dprinting.stackexchange.com/questions/10573/what-is-a-printer-console-terminal) you are able to communicate with the printer and see output return.

With G-code [`M92`](https://reprap.org/wiki/G-code#M92:_Set_axis_steps_per_unit) you get a report of the current settings. These should be verified with the mechanics (e.g. gearing) and electronics used (e.g. micro stepping value).

In firmware configuration this is found in file Configuration.h (*note: this is an **example** and may differ from your values!*):

```
/**
 * Default Axis Steps Per Unit (steps/mm)
 * Override with M92
 *                                      X, Y, Z, E0 [, E1[, E2...]]
 */
#define DEFAULT_AXIS_STEPS_PER_UNIT   { 80, 80, 4000, 500 }

```

The third value is the setting for the Z axis. Your value is too low and should be increased according to the fore mentioned mechanics and electronics.

By sending the command `M92 Zxxx` (where xxx denotes the value you calculated) will update the steps per mm.

There are [online calculators](https://blog.prusaprinters.org/calculator_3416/) that can help you calculate the correct value.

As an example, a very common lead screw is the trapezoid Tr8x8(p2). Assuming that you have normal 200 steps/rev steppers and use 16 micro steps and have the fore mentioned lead screws with a 2 mm pitch, the Z requires 1600 steps per mm.

You should check your hardware, stepper, screw and driver. Note that 8000 is a strange value, your Z axis is only about 10 % off, if 8000 value is correct for 200 (1.8°), 1/32, 0.8 pitch, but also for 400 (0.9°), 1/16, 0.8 pitch (M5).

Considering you are losing about 10 % it can also be that the Z stepper is missing some steps. Increasing the Vref of the stepper motor drivers may help with that.


---

