For my project I decided to print this modified 20-sided die (typically called a d20). According to the creator, the design was inspired by the Turner’s Cube, which was originally an exercise in milling. Allegedly, the student would be given a cube and be told, “Here, make this.”

From this, the creator became inspired to make a Turner’s Icosohedron, then realized that he could just add some numbers, and Bam! here I am.

My first print, more of a proof of concept than anything, since I was using the less delicate MakerGear printers, came out like this.

As you probably can’t see, the very center, where the ‘die’ part of the print is, is minuscule. It was barely attached, there was stray filaments falling about, and the numbers were hardly legible. So I realized that I either had to make the whole thing significantly bigger or make the ‘die’ core bigger. Of course, I couldn’t resist making the project far more difficult than it needed to be, and I also wanted to try to preserve the feel of a standard d20 in size, so I decided to edit the file and make the core bigger with respect to the outer shells. Thankfully, it didn’t turn out to be as difficult as I thought; most of the work was simply finding the right CAD package. I ended up using Autodesk’s MeshMixer to select the faces of the core and simply scale it up to ‘eat up’ the shell I wanted to remove, then used the make solid tool to recompile it into a printable shape.

My final prints turned out pretty well, but there is definitely still room for improvement. My first final print was made on the Form Labs 2, an SLA printer. My favorite part about this one was how clear the numbers are- at least most of them. Unfortunately, the support structure that it uses created a bunch of attachment points, and those points left pretty visible marks on the surface of my print, including several of the numbers.

Here, we see the support, the good side (the number’s a 14, it’s rotated funny), and the bad side of the Form Labs version. (PS, it’s really hard to photograph the inside of this thing.)

My other print was on the Objet. The good thing about this one was that the end product was very clean, with few defects, and the support came off cleanly. However, I think that the white material makes it much harder to read the numbers.

Were I to do this again, I would first scale them both up a bit. I tried to find the dimensions of a standard die when printing, but the numbers I used came out too small, which certainly didn’t help the other issues I had. Also, I found out that you can turn off internal support on the Form Labs, so I would also do that.

Price: apparently $0.25 ea.
Estimated Cost: $129.10
Time: $90- 6 hrs @ $15/hr (Also, 3 hours of babysitting the printer, but I wasn’t required to be there)
Machine Time: $30- 6 hrs @ $5/hr
Materials- $9.10: ~.10$ on MakerGear, $1 on Form Labs, $8 on Objet