Laser CNC

Laser Cutting and engraving

Life cycle:

1. Design the 2D object (Inkscape, or any graphical editor)
2. Export to a compatible format: Gcode or DXF
   • Use Inkscape extensions to generate the g-code, such as
   • Gcodetools - included with Inkscape, but not as well supported
   • Jtech Laser Tool plugin
3. Send it (the G-code program or DXF file) to the laser cutter. This is usually done with another program, such as
   • LaserGRBL or
   • Engraver Master
   • or a machine-specific program.

Inkscape for Laser cutting

A few short and useful tutorial videos:

• Laser Cutting With Inkscape Tutorial
• Inkscape with Jtech Laser Tools plugin for g-code

A short tutorial

1. Open Inkscape
2. Document properties: Set material size (height, width to 100x100 mm)
3. Draw your thing, for example, a letter A in your favorite font
4. Optionally resize. Can use lock icon in the toolbar to keep the aspect ratio.
5. Open Align and Distribute toolbox, and center the drawing on the page.
6. Menu -> Object to path
7. Change the view to Outline
8. Tools => Gcodetools => Path to Gcode
   • Preferences => enter file name
   • Apply
9. Open the new Gcode file and make the necessary edits

Inkscape extensions: Gcodetools

The following notes are for using Inkscape on Linux, e.g. Ubuntu. On Windows or MacOS you may encounter similar problems, depending on your software, e.g. Python configuration.

Problem1: python 2.7 vs 3 for gcodetools

Gcodetools is an extension for Inkscape for G-code export. It appears to be written for Python 2, while the newest Inkscape appears to be running Python 3. There might be problems with running the extensions. Change the default version for python to be 2.7 like this:

• Open Inkscape preferences, usually here: ~/.config/inkscape/preferences.xml
• Search for

<group
    id="extensions"
    …
    org.ekips.filter.gears.pitch="20"
    org.ekips.filter.gears.angle="20" />

• Change to - add the following:

<group
    id="extensions"
    python-interpreter="/usr/bin/python2.7"
    …
    org.ekips.filter.gears.pitch="20"
    org.ekips.filter.gears.angle="20" />

• More info here: https://wiki.inkscape.org/wiki/index.php/Extension_Interpreters

Problem2: unittouu

After running gcodetools extension you may get the error:

AttributeError: 'module' object has no attribute 'unittouu'

The solution is to update the gcodetools.py as follows. For me, this was on the line 5864 where inkex.unittouu() is called. The problem is that it is referenced as

doc_height = inkex.unittouu(...

Fix this as follows:

doc_height = self.unittouu(...

Inkscape extensions: JTechPhotonics

Alternative, easy to use extension for inkscape to create gcode is J Tech Laser Tool Plugin

• For Inkscape version 0.92:
  • Click here to download the plugin

Here is a Youtube tutorial for how to use it:

• Inkscape with Jtech Laser Tools plugin for g-code

Resources

• G-code description and codes on Wikipedia