GCode-Tools/Remove Small Moves

GCode Small-Move Remover

PowerShell script that removes gcode cutting moves where X and Y coordinates differ from the previous kept position by less than or equal to a configurable threshold (default 0.0006). These near-zero moves cause Komo CNC machines to throw ERROR: CRC Fault.

Problem

Komo controllers reject cutting moves where the actual displacement in X and Y is negligibly small. For example:

N7633 G1 X23.1756 Y27.9265 Z0.7700 F150.
N7634 G1 X23.1757 Y27.9268 Z0.7700 F150.  <-- dX=0.0001, dY=0.0003 (CRC Fault)
N7635 G1 X23.1962 Y27.9797 Z0.7700 F150.
N7636 G1 X23.1963 Y27.9799 Z0.7700 F150.  <-- dX=0.0001, dY=0.0002 (CRC Fault)
N7637 G1 X23.2163 Y28.0330 Z0.7700 F150.

Lines N7634 and N7636 move less than 0.0006 in both X and Y from the previous position, which Komo sees as invalid and halts with a CRC Fault error.

Solution

The script parses .OUT gcode files and removes cutting move lines (G1, G2, G3) where both X and Y differ from the last kept position by less than or equal to the threshold, and there is no Z change. This eliminates the CRC Fault triggers while preserving all meaningful toolpath data.

What gets removed

• G1/G2/G3 lines where dX <= threshold AND dY <= threshold AND Z is unchanged

What is always kept

• Z moves - any line where Z changed is never removed
• G0 (rapid) positioning lines
• G28 (home return) lines
• G52 (coordinate offset) lines
• M-codes, comments, tool changes, and all other non-cutting lines

Usage

# Basic - creates *_cleaned.OUT next to the original
.\Remove-SmallMoves.ps1 -InputFile "C:\path\to\file.OUT"

# Specify output file
.\Remove-SmallMoves.ps1 -InputFile "file.OUT" -OutputFile "file_fixed.OUT"

# Custom threshold
.\Remove-SmallMoves.ps1 -InputFile "file.OUT" -Threshold 0.001

Parameters

Parameter	Required	Default	Description
InputFile	Yes	-	Path to the input gcode file
OutputFile	No	*_cleaned.OUT	Path for the cleaned output file
Threshold	No	0.0006	Max X or Y difference for removal

Example Output

GCode Small-Move Remover
========================
Threshold: <= 0.0006 in both X and Y
Input:      file.OUT (8864 lines)
Output:     file_cleaned.OUT (8310 lines)
Removed:    554 lines

Sample removed lines (first 20):
  Line 36 removed: X=28.0339 Y=25.8585 Z=0.77 (dX=0.0002, dY=0.0003, dZ=0)
  Line 47 removed: X=27.7644 Y=27.1713 Z=0.77 (dX=0, dY=0, dZ=0)
  ...

How It Works

1. Reads the input file line by line
2. Extracts X, Y, Z coordinates using regex
3. For cutting moves (G1/G2/G3) only:
   • If Z changed significantly (> 0.0001), the line is always kept
   • If Z is the same, compares X and Y against the last kept position
   • If both dX and dY are within threshold, the line is removed
4. Updates the last known X/Y/Z position from kept lines only (removed lines don't update position tracking)