---
tag: m0404
title: Set Filament Diameter
brief: Set the nominal diameter for filament width sensor auto-flow
author: thinkyhead

requires: FILAMENT_WIDTH_SENSOR
group: control

codes: [ M404 ]

notes: Requires `FILAMENT_WIDTH_SENSOR`.

parameters:
  -
    tag: W
    optional: true
    description: The new nominal width value
    values:
      -
        tag: linear
        type: float

examples:
  -
    pre: Set the diameter to 1.75mm
    code: M404 W1.75
  -
    pre: Get the current width
    code:
     - M404
     - '> Filament dia (nominal mm): 1.75'

---

Report or set the nominal filament width, such as 1.75 or 3.00.

This value is used to determine the percentage difference when auto-adjusting flow in response to the measured filament width, and should match the value used for filament width in your slicer settings.