A D20 is a 20-sided die often used in role playing games like D&D. Geometrically, it is an icosahedron, consisting of 20 triangular sides.
It may seem that sticking server computer components inside is completely random and unnecessary, but this was in fact a machine which we would hook to the LAN and run games (like Team Fortress 2) and apps like Teamspeak and a live video stream. Computer components generate heat which can be a challenge for adhesives, and everything would need to remain structurally sound for at least the 4 day duration of the summer LAN. As it turned out, it held up for weeks.
Here's a look at the finished product:
Step 1: Planning
The nice thing about an icosahedron is that it's just a series of triangles, which are easy to build and are naturally a sturdy shape. Once we had an idea of the interior space we needed, we figured out the length of the leg of any triangle and got started.
Step 2: Sheets and Tubes
Once we had a four-ply sheet, we'd roll it up as tight as possible. Once rolled, we spiral wrapped another layer of tape from one end to the other. When finished the tube was very strong and about an inch in diameter! Just to go a step further - the tubes were usually slightly hollow at the center - we stuffed tiny scraps of duct tape to fill the tubes to add a little more rigidity.
A group of us spent a few nights just mass producing tubes like this.
Step 3: Making Triangles
As things progressed we found that our tubes were not all exactly the same length, and that little differences would start adding up and distort our shape. The first few tubes were cut to length with a utility knife, but it was really tough chopping through nearly a solid inch of tape. We also realized that the tubes would look much nicer if they were mitered to fit snuggly together at each corner.
We looked at each other and knew what must be attempted...
we had to use a miter saw on our duct tape!
It worked like a charm! *
* Your mileage may vary. Use appropriate caution. Also be prepared to end up with a very gummy saw blade (and maybe more) when you're finished.
Step 4: More Structure
After the bottom half came together, we made a large internal triangle to help support the shape and to hold our motherboard.
As the last of the sides were added, some more tubes were added inside for bracing. At this point, before adding any computer components, the structure was a hefty 20+ pounds of nothing but duct tape!
Step 5: Putting in the Computer Components
As for cosmetics we added a red cathode tube for a little light inside. And for even more needless bling, we charlieplexed a bunch of red LEDs (one mounted at each corner) and programmed them to randomly flash.
The specs of the machine are pretty low end (we used old gear for the build), but it was plenty to handle its tasks. If you're curious:
* Pentium P4 3.0 GHz
* Intel SFF Motherboard
* 2GB DDR2 RAM
* 80GB SATA HDD
* 475W PSU
* 1 120mm LED fan (rear)
* 1 92mm fan (cpu)
Step 6: Finishing Touches
Remember EVERYTHING that's not electrical is duct tape, anything else would be like cheating to us. Even the letters and numbers we added were cut from red duct tape.
The final tally was a whopping 22 rolls of tape and about 127 man-hours went into this thing. We prefer not to think of the dollar amount behind that - we don't use cheap tape either - but then again it's not everyday you build a 3-foot wide duct tape D20!