> For the complete documentation index, see [llms.txt](https://manual.rotrics.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://manual.rotrics.com/gcode/marlin-original-commands/marlin-m003-laser-on.md).

# \[Marlin] M003 - Laser On

{% hint style="success" %}
**📅Update: 2020/09/18**
{% endhint %}

## Description

Wait for moves to complete, then set the spindle speed (clockwise) or laser power.

## Notes

* 'S is interpeted as the configured value range: PWM (default), Percentage, or RPM. (See `CUTTER_POWER_UNIT`)'
* "[`M3`](https://app.gitbook.com/docs/gcode/M003.html) and [`M4`](https://app.gitbook.com/docs/gcode/M004.html) aren't needed with `LASER_POWER_INLINE` and `LASER_MOVE_POWER` enabled. Power is set directly in [`G1`](https://app.gitbook.com/docs/gcode/G000-G001.html)…[`G5`](https://app.gitbook.com/docs/gcode/G005.html)"

## Usage

`M3` `[I<mode>]`

### Parameters

* `[I<mode>]` Inline mode ON / OFF.

## Examples

Set spindle rotation clockwise at 50% with `CUTTER_POWER_UNIT` set to `PERCENT`

```
M3 S50
```

Set spindle rotation clockwise at 6K RPM with `CUTTER_POWER_UNIT` set to `RPM`

```
M3 S5000
```

Set laser power to 50% in PWM

```
M3 O128
```

Turn on the laser at full / `SPEED_POWER_STARTUP` power

```
M3
```

Fire laser at 80% on next G1,G2 and G3 move

```
M3 S204 I
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://manual.rotrics.com/gcode/marlin-original-commands/marlin-m003-laser-on.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.