G-code replicator

README.md

Requirements

The slicer needs to be configured to emit EXCLUDE_OBJECT_(DEFINE|START|END) commands. Also the printer has to support Firmware Retraction (G10 and G11 commands).

Usage

python replicate.py COUNT_X COUNT_Y SPACING_X SPACING_Y MOVE_Z

• COUNT_X: X-axis replication count
• COUNT_Y: Y-axis replication count
• SPACING_X: X-axis spacing between object centers (millimeters)
• SPACING_Y: Y-axis spacing between object centers (millimeters)
• MOVE_Z: Z-axis clearance during move between objects

LICENSE

MIT License

Copyright (c) 2026 tana_ash

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

replicate.py

# G-code replicator
# Written by tana_ash. May 2026.
# Licensed under the MIT License.

import sys
import re
import itertools

filename = sys.argv[1]
count_x = int(sys.argv[2])
count_y = int(sys.argv[3])
spacing_x = int(sys.argv[4])
spacing_y = int(sys.argv[5])
move_z = int(sys.argv[6])

exclude_object_define_p = re.compile(r'^EXCLUDE_OBJECT_DEFINE NAME=(?P<name>[\w.]+) CENTER=(?P<center>[0-9.]+,[0-9.]+)( POLYGON=(?P<polygon>\[(\[[0-9.]+,[0-9]+\])(,\[[0-9.]+,[0-9.]+\])*\]))?', re.IGNORECASE)
exclude_object_start_p = re.compile(r'^EXCLUDE_OBJECT_START NAME=(?P<name>[\w.]+)', re.IGNORECASE)
exclude_object_end_p = re.compile(r'^EXCLUDE_OBJECT_END', re.IGNORECASE)
g90_p = re.compile(r'^G90', re.IGNORECASE)
g91_p = re.compile(r'^G91', re.IGNORECASE)

object_defs = dict()
current_object_name = None
stored_gcode = []
relative = False
last_shift_x = 0
last_shift_y = 0

for line in open(filename).readlines():
    line = line.rstrip()
    
    match = exclude_object_define_p.match(line)
    if match:
        name = match.group('name')
        center = [float(coord) for coord in match.group('center').split(",")]
        polygon = match.group('polygon')
        object_defs[name] = (center, polygon)
        print(f"Object {name} defined", file=sys.stderr)
        
        for i in range(count_x * count_y):
            new_name = name + f"_{i}"
            cmd = f"EXCLUDE_OBJECT_DEFINE NAME={new_name} CENTER={center[0]},{center[1]}"
            # TODO: polygon coordinate conversion
            if polygon:
                cmd += f" POLYGON={polygon}"
            print(cmd)

        continue

    match = exclude_object_start_p.match(line)
    if match:
        name = match.group('name')
        if name in object_defs:
            current_object_name = name
        else:
            print(f"Object {name} not found", file=sys.stderr)

        continue

    match = exclude_object_end_p.match(line)
    if match:
        if current_object_name is None:
            print("Unexpected EXCLUDE_OBJECT_END", file=sys.stderr)

        (center_x, center_y), _ = object_defs[current_object_name]

        for i, j in itertools.product(range(count_x), range(count_y)):
            shift_x = spacing_x * (i - (count_x - 1) / 2)
            shift_y = spacing_y * (j - (count_x - 1) / 2)
            
            print(f"EXCLUDE_OBJECT_START NAME={current_object_name}_{count_y * i + j}")
            
            # Retract
            print("G10")
            # Raise nozzle
            print("G91")
            print(f"G0 Z{move_z}")
            # Move to the current object center
            print("G90")
            print(f"G0 X{center_x} Y{center_y}")
            # Move to the new object center
            print(f"G91")
            print(f"G0 X{shift_x - last_shift_x} Y{shift_y - last_shift_y}")
            # Shift coordinate
            print(f"G92 X{center_x} Y{center_y}")
            # Lower nozzle
            #print("G91")
            #print(f"G0 Z{-move_z}")
            # Restore relative/absolute mode
            if relative:
                print("G91")
            else:
                print("G90")
            # Unretract
            print("G11")

            last_shift_x = shift_x
            last_shift_y = shift_y
            
            for stored_line in stored_gcode:
                print(stored_line)

            print(f"EXCLUDE_OBJECT_END")

        current_object_name = None
        stored_gcode = []
        
        continue

    match = g90_p.match(line)
    if match:
        print("Changed to absolute mode", file=sys.stderr)
        relative = False
        
    match = g91_p.match(line)
    if match:
        print("Changed to relative mode", file=sys.stderr)
        relative = True

    if current_object_name:
        stored_gcode.append(line)
        continue
    
    print(line)