Metalcasting by 3D Printer

Starting at the End

I used 3D printing to create a pendant for a friend.  The steps I took are below.  However, I’m so excited about the end product that I wanted to start by showing it off.

Picture of the finished pendant

The Adventure Begins

On a whim, I asked a friend to give me an idea for something to 3D print.  She’s a huge fan of Garth Nix’s Abhorsen series and admires the Clayr.  She suggested creating a pendant based on their sigil.  After a couple hours work, I had this:

From here, I started thinking about how nice it would be to have this in metal - to make it into a proper pendant that she could wear.  After quite a bit of looking online, I settled on trying to cast it in a low-melting point alloy.  These are usually used in thermal fail-safes in industrial machinery, rapid prototyping or die-casting.

Many of these alloys contain lead - obviously an issue for something that is to be worn.  The most prominent non-toxic option is Field’s Metal.  However, that stuff is EXPENSIVE. …

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New software - GCode splitter!

Over the last few months, I’ve been silent as I transitioned from the life of a student to the life of a professional.  But!  I have finished that transition (for the most part) and am now back.  I even bring new software with me.

This new software (which has the rather uncreative name “gcode splitter”) is a utility for use in 3D printing.  I have acquired a 3D printer for me to experiment with.  The printer I own has one printhead.  However, many of my designs require two or more materials.  (I’m using a lot of “exotics”, like conductive or flexible plastics).  It occurred to me that as long as the two materials never shared a layer (or only shared one layer at the interface), I could split the print into parts, change the plastic between prints and thereby end up with multi-material objects.

The code is available on my github.  The utility has fairly simple inputs - it takes a (specially formatted) gcode file, followed by the locations in which the …

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Extruding Silhouettes for 3D Printing with Inkscape and OpenSCAD

I recently found myself in a position where I wanted to extrude a logo so I could 3D print it.  Unfortunately, this is a pretty difficult process to figure out without instructions.  Therefore, I decided to document it.  This process assumes you’re starting with a pixel-based image (bitmap, jpg, etc).  If instead you have a vector graphic (SVG, etc) you should be able to do this by starting at the export step.

Software Used

  • Inkscape 0.48.4-r9939 (latest through Debian testing as of time of writing)
  • OpenSCAD 2013.06.09 (Also Debian-testing latest)
  • A Debian-testing system (though this shouldn’t matter)


As the highest level we need to accomplish three steps:

  1. Convert the pixel (bitmap) image to a vector graphic
  2. Export the vector graphic in a format OpenSCAD will use
  3. Extrude it in OpenSCAD

The last step is documented solely because there are a number of little details which can totally stop this process from working if you don’t get them exactly correct. …

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Defense Distributed, 3D Firearms and People Who Should Have Shut Up and Left It To The Pros. Oh my.

Edit: Just before the publication of this article, Defense Distributed voluntarily removed the designs for the Liberator from their website, at the request of the Department of Defense.  In my opinion, this is Defense Distributed getting the legal fight with the government it was spoiling for.  More on that to follow.

Hello again world.  How are you today?  It’s been a while since I last posted, mostly due to school.  Good news is that I had an awesome semester and worked on some very cool projects.  A little polishing, and I’ll happily show them off here.

One of the things I’ve been very intimately involved with this semester is 3D printing.  Consequently, I have some thoughts to share on Defense Distributed, which is aiming to make a 3D printed firearm.  More specifically, I have thoughts on their 3D printed firearm and how much it does - and doesn’t - change the security playing field.  I also have a few thoughts on the attitude and approach of Defense …

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