M92 - Set Axis Steps-per-unit

motion Set the number of steps-per-mm, per-inch, or per-degree

Use M92 to set the steps-per-unit for one or more axes. This setting affects how many steps will be done for each unit of movement.

Units will usually be set in steps-per-millimeter unless:

The firmware has INCH_MODE_SUPPORT enabled and has been set to Inches Mode by G20 or by having inches as the default unit.
The machine is a SCARA in which case the A and B axes are configured in steps-per-degree, not steps-per-distance.
Any axis for which AXISn_ROTATES is enabled is configured in steps-per-degree.

Get the current steps-per-unit settings using M92 with no parameters or M503 on older versions of Marlin.

With EEPROM_SETTINGS enabled:

This setting for all axes is saved with M500 and loaded with M501.
M502 resets steps-per-unit for all axes to the values from DEFAULT_AXIS_STEPS_PER_UNIT.

M92 [A<steps>] [B<steps>] [C<steps>] [E<steps>] [T<index>] [U<steps>] [V<steps>] [W<steps>] [X<steps>] [Y<steps>] [Z<steps>]

`[A<steps>]` 2.0.9 I_DRIVER_TYPE AXIS4_NAME 'A'	A steps per unit
`[B<steps>]` 2.0.9 J_DRIVER_TYPE AXIS5_NAME 'B'	B steps per unit
`[C<steps>]` 2.0.9 K_DRIVER_TYPE AXIS6_NAME 'C'	C steps per unit
`[E<steps>]`	E steps per unit
`[T<index>]`	Target extruder (Requires `DISTINCT_E_FACTORS`)
`[U<steps>]` 2.1 U_DRIVER_TYPE AXIS7_NAME 'U'	U steps per unit
`[V<steps>]` 2.1 V_DRIVER_TYPE AXIS8_NAME 'V'	V steps per unit
`[W<steps>]` 2.1 W_DRIVER_TYPE AXIS9_NAME 'W'	W steps per unit
`[X<steps>]`	X steps per unit
`[Y<steps>]`	Y steps per unit
`[Z<steps>]`	Z steps per unit

Set E steps for a new extruder

M92 E688.4