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G29 - Mesh Bed Leveling

1.0.0-beta calibration Measure Z heights in a grid, enable leveling compensation MESH_BED_LEVELING

With Mesh Bed Leveling (MBL) you can interactively measure a grid of Z heights without a bed probe. The only tool required is a piece of paper or a feeler gauge. MBL uses the mesh to compensate for variations in height across the bed. Comparable to using AUTO_BED_LEVELING_BILINEAR with PROBE_MANUALLY.

This feature is enabled with the MESH_BED_LEVELING option in Configuration.h. Users with a probe should enable one of the AUTO_BED_LEVELING_* options instead.

To do Mesh Bed Leveling from your host software:

  1. Use G29 S0 to get the current status and mesh. If there’s an existing mesh, you can send M420 S1 to use it.
  2. Use G29 S1 to move to the first point for Z adjustment.
  3. Adjust Z so a piece of paper can just pass under the nozzle.
  4. Use G29 S2 to save the Z value and move to the next point.
  5. Repeat steps 3-4 until completed.
  6. Use M500 to save the mesh to EEPROM, if desired.

To do LCD Bed Leveling with your controller: (Requires LCD_BED_LEVELING)

  1. Select Level Bed then choose Level Bed (not Cancel) in the sub-menu.
  2. Wait for Homing XYZ to complete.
  3. When Click to Begin appears, press the controller button to move to the first point.
  4. Use the controller wheel to adjust Z so that a piece of paper can just pass under the nozzle.
  5. Press the controller button to save the Z value and move to the next point.
  6. Repeat steps 4-5 until completed.
  7. Use Control > Store memory to save the mesh to EEPROM, if desired.

Usage

G29 S<0|1|2|3|4|5>

Argument Description
S<0|1|2|3|4|5>
  • S0:

    Produce a mesh report (see example 1)

  • S1:

    Start probing mesh points

  • S2:

    Probe the next mesh point

  • S3:

    Manually modify a single point

  • S4:

    Set Z-Offset, positive away from bed, negative closer to bed.

  • S5:

    Reset and disable mesh

Example

S0 produces a mesh report as follows:

+----> X-axis  1-n
|
|
v Y-axis  1-n