Prusa XL - Belt Tension Equalization Gcode G-Code

This G-code is a service and maintenance utility for the Prusa XL, designed to evenly distribute belt tension after manual belt adjustments.

When adjusting belt tension, the tension is often unevenly distributed along the belt path.
This file moves the XY system across the maximum usable travel range to allow the belts to settle evenly before final evaluation or further adjustment.

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VIsit my Prusa XL Belt Tension Alignment Calibration Guide

This is a powerful guide that helps you adjust the belt tension and alignment on your Prusa XL perfect evenly: https://investegate.de/prusa-xl-belt-tension-alignment-calibration-guide/

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What this G-code does

• Performs a large XY square (359 × 359 mm) covering almost the entire bed

• Includes both diagonals

• Runs the motion clockwise and counter-clockwise

• Uses two speeds:

  • Moderate speed for initial settling

  • High speed for final tension equalization

• No heating

• No extrusion

• No printing

• No tool pickup - Parks current tool

• Pure mechanical motion only

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Purpose

• Equalize belt tension after adjustment

• Reduce localized belt preload

• Improve repeatability after re-tensioning

• Detect abnormal noises, binding, or uneven belt behavior

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Important notes

• This is not a calibration print

• This file is not meant to improve print quality directly

• The printer displays a warning message at startup. Simply confirm.

• Always supervise the printer while running

• Stop immediately if unusual sounds or vibrations occur

• Run this file once after each belt adjustment

• Gcode is packaged as a zip file because Printables blocks custom gcode uploads

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Recommended workflow

1. Adjust belt tension

2. Run this G-code once

3. Listen and observe motion

4. Measure the Belt Tension

5. Re-adjust if necessary

6. Run again if adjustments were made

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Technical details

• XY homing only

• Safe Z height before motion

• Simple and symmetric motion path

• Designed for repeatable workshop use

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G-Code

; ======================================================
; Prusa XL – Belt Tension Equalization Test
; XY-ONLY HOMING (NO Z HOMING and NO TOOL)
; ------------------------------------------------------
; Author: INVESTEGATE
; Website: https://investegate.de/prusa-xl-guides/
; Date: 2026
;
; PURPOSE:
; Short belt tension equalization run after each
; manual belt tension adjustment. After that, measure the belt tension. 
;
; HOMING:
; - X and Y axes only
; - Z homing intentionally skipped
;
; TOOL:
; - Parks current tool
; - No tool while running
;
; SPEED & DIRECTION:
; - Pass 1: F6000  / CW
; - Pass 2: F12000 / CCW
;
; MOTION:
; - Large square (359 mm) + both diagonals
; - Simple, symmetric path
; - Z raised to 50 mm once for safety
;
; IMPORTANT:
; - Only use if Z position is known and safe
;
; USE AT YOUR OWN RISK.
; ======================================================
; ===== Belt Tension Test START =====
G90
M83
; ---------- HOME X AND Y ONLY ----------
G28 X Y
; ---------- SAFE Z ----------
G1 Z80 F2000
; ---------- PARK TOOL IF ACTIVE ---------- 
P0 ; Parks tool - THIS LINE has to DELETE for printers without toolchanger.
; ---------- WARNING MELODY ----------
M117 BELT TENSION Equalization Starts
M300 S2000 P120
G4 P150
M300 S2000 P120
G4 P150
M300 S2000 P300
G4 P500
; ---------- MOTION LIMITS ----------
M204 P4000 T4000
M205 X15 Y15
; ---------- BOUNDARIES ----------
; Square size: 359 x 359 mm
; A (0.5,0.5)     B (359.5,0.5)
; D (0.5,359.5)   C (359.5,359.5)
; ======================================================
; PASS 1 – F6000 / CW
; ======================================================
G1 F6000
G1 X0.5   Y0.5
G1 X359.5 Y0.5
G1 X359.5 Y359.5
G1 X0.5   Y359.5
G1 X0.5   Y0.5
; Diagonals
G1 X359.5 Y359.5
G1 X0.5   Y359.5
G1 X359.5 Y0.5
G1 X0.5   Y0.5
; ======================================================
; PASS 2 – F12000 / CCW
; ======================================================
G1 F12000
G1 X0.5   Y0.5
G1 X0.5   Y359.5
G1 X359.5 Y359.5
G1 X359.5 Y0.5
G1 X0.5   Y0.5
; Diagonals
G1 X359.5 Y0.5
G1 X0.5   Y359.5
G1 X359.5 Y359.5
G1 X0.5   Y0.5
; Measure Position
G1 X181.5 Y281 F8000
; ---------- FINISH MELODY ----------
M300 S1200 P150
G4 P200
M300 S1500 P150
G4 P200
M300 S1800 P300
G4 P500
; ---------- END ----------
G1 Z80 F2000
M84

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Disclaimer

Use at your own risk.
This G-code performs fast, large-area movements and is intended for users familiar with Prusa XL maintenance and mechanics.

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Created by: investegate.de