How to Use Auto Bed Leveling in 3D Printing: Simple Guide

To use auto bed leveling in 3D printing, first install a compatible sensor on your printer's printhead. Then, run the printer's bed leveling command to let the sensor measure the bed surface and adjust the nozzle height automatically during printing.

Syntax

Auto bed leveling involves commands and settings in your 3D printer's firmware and slicer software. The main command to start leveling is usually G29, which triggers the sensor to probe multiple points on the bed. Before that, G28 is used to home the printer.

• G28: Homes all axes to set a reference point.
• G29: Starts the auto bed leveling process.
• Firmware settings: Enable auto bed leveling and configure sensor offsets.
• Slicer settings: Use the leveling mesh for adjusting print layers.

gcode

G28 ; Home all axes
G29 ; Start auto bed leveling

Output

Printer homes all axes, then probes bed at multiple points to create a leveling mesh.

Example

This example shows how to run auto bed leveling on a printer with a BLTouch sensor. The commands home the printer, run the leveling, and then start printing with the adjusted bed mesh.

gcode

G28 ; Home all axes
G29 ; Auto bed leveling
M420 S1 ; Enable leveling mesh
G1 Z0.2 F3000 ; Move nozzle close to bed
; Start printing commands follow

Output

Printer homes, probes bed points, enables leveling compensation, and positions nozzle for printing.

Common Pitfalls

Common mistakes when using auto bed leveling include:

• Not homing the printer (G28) before leveling, causing incorrect measurements.
• Incorrect sensor offset settings, leading to wrong nozzle height.
• Using a dirty or uneven bed surface that confuses the sensor.
• Failing to enable the leveling mesh in firmware or slicer, so adjustments are ignored.

Always clean the bed and verify sensor installation before starting.

gcode

Wrong way:
G29 ; Auto bed leveling without homing

Right way:
G28 ; Home all axes
G29 ; Auto bed leveling

Quick Reference

Tips for smooth auto bed leveling:

• Always home the printer first with G28.
• Run G29 to probe the bed surface.
• Check and set correct sensor offsets in firmware.
• Enable leveling mesh compensation with M420 S1.
• Keep the bed clean and free of debris.

Key Takeaways

Always home your printer with G28 before starting auto bed leveling.

Use G29 to run the auto bed leveling sensor probe across the bed.

Set correct sensor offsets in firmware to ensure accurate nozzle height.

Enable the leveling mesh compensation in firmware or slicer to apply adjustments.

Keep the print bed clean and smooth for reliable sensor readings.