Skeinforge is a tool that converts a 3D model (an STL file) into a set of specific fabricator commands (move the tool head here, squirt out some goop, then go there) necessary to print your 3D object.

See: the Skeinforge website at


The Skeinforge source code is most conveniently downloaded from where it resides within the ReplicatorG source tree:

If you are running linux and have subversion installed, you can check out the entire replicatorG source tree like this:

cd where-ever-you-want-the-files-to-be
svn checkout replicatorg-read-only

How to convert STL to G-Code

(work in progress)

Run skeinforge:

cd whereever-skeinforge-is
python ./

You should see the skeinforge preferences GUI pop up:


I have no idea what those settings mean, so I just assume the defaults are acceptable and clicked the "Skeinforge" button to get down to bizness.

I then selected my STL file in the file selection dialog, and skeinforge got to work. I saw some text blaze by that looked like this:

On the X axis, the extrusion starts at -16 mm and ends at 16 mm, for a width of 31 mm
On the Y axis, the extrusion starts at -17 mm and ends at 17 mm, for a depth of 33 mm
On the Z axis, the extrusion starts at 0 mm and ends at 14 mm, for a height of 13 mm
The average feedrate is 25 mm/s, (1473 mm/min).
The extruder speed is 255
The extruder was extruding 91% of the time.
The extruder was toggled 372 times.
The extrusion width is 0.675 mm.
The following procedures have been performed on the skein:
The layer thickness is 0.375 mm.
The text has 10536 lines and a size of 329.0 KB.
The total build time is 740 s.
The total distance extruded is 16623 mm.
The total distance traveled is 18173 mm.
The volume extruded is 4 cc.

The exported file is saved as /home/jonmayer/Desktop/PolyChocolateIcoV02-fixed_export.gcode
It took 22 seconds to export the file.

Pay attention to that final line describing "volume extruded." If the volume extruded is zero, then there is something wrong with your model — most likely, your model does not comprise a manifold solid. See Troubleshooting your 3D Model for more instructions.

If everything went well, you will then see a new GUI window labelled "Skeinview from HydraRaptor." It's empty: do not panic. This GUI interface is showing you the gcode steps to assemble your model, one layer at a time. Click the "Up" button to see the first layer. It will look something like this:


The first two layers are a sparse grid that Skeinforge always starts the bottom of your model with. This grid provides the skeleton for the structure to be fabricated above it, and is designed to be easily trimmed away from the fabricated product.

Click "up" a couple of additional times, and you'll begin to see the first few layers of your actual object.


When you are satisfied, click "Exit."

Look in the same directory where your STL model resides. You should see a new file alongside it. If your file was named "model.stl", the new file will be named "model_export.gcode".

Congratulations! This is your g-code file. Now you get to go take your g-code file to ReplicatorG to fabricate it on your MakerBot!

Standard Preamble and Postscript

Skeinforge lets you insert canned initialization and finalization steps into the produced g-code. The recommended g-code snippets are here:


Tips and Tricks

If you are on a mac, and skeinforge just wont launch instead of clicking on "" click on "".

When you skeinforge something, it will appear to "freeze" DO NOT exit, this just means that it is working, give it some time.

skeinforge 0007

If, after you skeinforge an object skeinforge actually freezes. All you have to do is go to profile, behold, and uncheck it. This will make it so it gives you the skeinview and not the incredibly-hard-to-render 3-D model.

Skeinforge Calibration Logs

Unless otherwise stated, the content of this page is licensed under GNU Free Documentation License.