> For the complete documentation index, see [llms.txt](https://docs.voltera.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.voltera.io/docs/repairs/nova/nova-repair-guides-catalog/simple-troubleshooting/tool-port-homing-sensitivity-adjustment.md).

# Tool Port Homing Sensitivity Adjustment

{% hint style="warning" %}
**Safety first!** Before starting any repair, take a moment to review the [safety information in your user manual.](https://docs.voltera.io/docs/nova/downloads/nova-user-manual) An online version of the guidelines can also be found [here.](https://docs.voltera.io/docs/nova/getting-started/safety-guidelines)
{% endhint %}

​Port homing errors occur when the motor controllers for the Z or C tool ports are not able to register the home position. Symptoms of this are the Z/C lim error codes and a grinding noise when trying to home. We can increase the sensitivity of the motor controller to register the home position more accurately through console commands.

## Before you begin

This guide will take you through updating NOVAs toolport homing sensitivity. Before beginning this guide you should have been in contact with our support team.

As you work through this guide please reach out to our email <support@voltera.io> or through the chat if you run into any issues or have any questions. We are more than happy to assist you virtually with this repair.&#x20;

{% hint style="success" %}
**When in doubt, reach out!**
{% endhint %}

#### Estimated Repair Time:

* 10 minutes

## Port homing sensitivity adjustment

{% stepper %}
{% step %}

### Connect to NOVA

Connect to your device via **device-name.myvoltera.io**

<figure><img src="https://lh7-rt.googleusercontent.com/slidesz/AGV_vUcqVbtmTdro1CkOGizG9xqbhpESC3_E1c6tGxXXQCpgZoDrOd7N_asI1vuw4EHP1vEZm_EKzS3ncieX45i5Gr4iY_99BKxTi0hREAUMcTszMHxT64kxMzMMm8lXOz_LLzJ4FoOFnBUrraKsnQrH9AHGSXwr29cq=nw?key=cDG6WHJxzRoqCdPmGm5Rb1QN" alt=""><figcaption></figcaption></figure>
{% endstep %}

{% step %}

### Ensure the ports are in the home position

Press the home button and ensure that both ports are in the raised position and level.

<figure><img src="/files/EcV6YQ2Ka7bfTk9yhkr6" alt=""><figcaption></figcaption></figure>
{% endstep %}

{% step %}

### Open the console

Open the console by clicking the `~` key and type the command `M520` to read the current stall guard values for the C or Z port.

{% hint style="warning" %}
The left tool port = C axis

The right tool port = Z axis
{% endhint %}

<figure><img src="/files/HViG1nHRzjuqcXCLM8Z1" alt=""><figcaption></figcaption></figure>
{% endstep %}

{% step %}

### Increase the homing sensitivity

Start by decreasing the stall guard value of the offending port to 13 using either the command: `M508 Z13` or `M508 C13`

{% hint style="warning" %}
Only adjust the port that you have been getting an error with.&#x20;

Left = C axis, Right = Z axis
{% endhint %}

<figure><img src="/files/sUc9AmnMDDjtutbOb6v1" alt=""><figcaption></figcaption></figure>
{% endstep %}

{% step %}

### Test sensitivity

Now press the home button 3 times back to back to test the new sensitivity value.&#x20;

If the error / grinding noise is still present keep decreasing the stall guard in increments of 2 until the error goes away.

<figure><img src="/files/q6SPzSzwPWxf0LT0ldQQ" alt=""><figcaption></figcaption></figure>

{% hint style="danger" %}
If you are decreasing the value below 7 and there still seems to be an issue homing the port there might be something else going wrong that this adjustment will not fix.&#x20;

\
Please reach out to our support team for further troubleshooting!
{% endhint %}
{% endstep %}
{% endstepper %}

## Adjustment Complete!

Congratulations, you have successfully adjusted NOVAs port homing sensitivity!

Please reach back out to our support team through \`email (<support@voltera.io>) or the chat to let them know everything went well or share any photos, details, and feedback.&#x20;

### Related error codes `Unable to move to z-motor (z-lim), switch did not trigger`

`Unable to measure at z-motor (z-lim), switch did not trigger during initial approach`

`Unable to move to c-motor (c-lim), switch did not trigger`

`Unable to measure at c-motor (c-lim), switch did not trigger during initial approach`


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