[ making cartridge cases ]

• To really be able to make gameboy games from scratch, you should also be able to make your own cartridges. From an economic standpoint, I suspect that it is cheaper to just buy old cartridges at tag sales and cut them up. But by casting your own, you can create new colors, embed metal particles, etc. A future project might include casting metal cartridge cases too.
• To learn how to do this, I signed up for a class in plastic casting/reproduction at The Crucible in Oakland, CA, during August 2006. with Billy Hiebert. The guy is a real master of mold-making and casting, which he does professionally.

1. The bottom of the cartridge is the simplest piece to cast because it consists of a flat, featureless bottom surface, which we can use as the top of our very simple mold.
   • Anchor the piece with to a well waxed board with clay, wax the piece, pour mold.
   • 
   • Mix and pour resin. Let it set (30-40 minutes for this resin) and remove
   • 
   • The interior seems to have been casted correctly, but it's a little too thick on the bottom...
   • 
   • ...so instead, wax a board (or use a sacrificial piece of paper under your waxed board), and after pouring the resin into the cast, use the board to press the surface flat.
   • 
   • Trim with an exacto knife, slightly sand the bottom, and it now fits perfectly. You can now make any color you like by mixing pigment into the resin.
   • 
2. To make the top portion, we will make a press-fit mold consisting of two pieces, since both sides are featured.
   • In the first stage, create a clay support which is flush to the top surface
   • 
   • Pour the cast and let it set (overnight).
   • 
   • Then carefully remove it the clay from the bottom, being sure to keep the cartridge original in position. Cut alignment notches into the side of the cast.
   • 
   • Then pour the top half of the cast, and let it cure. You will now have the two pieces shown in the center as the two halves of your press-fit mold.
   • 
   • Setup is everything. To create the cast, first spray both pieces of the cast with mold release. Then mix your resin and pour it into the portion with the finer features (left mold in below figure). Optionally, use a toothpick to remove air bubbles that may be trapped. You should pour enough resin to create a small "hill" at the top. Then press the top piece (right mold) onto the top. Put a small weight--enough to keep everything together but not enough to "squeeze" the rubber mold--on top and let the resin set.
   • 
   • Fits perfectly with our previously casted bottom piece, and with a standard factory-made gameboy bottom piece
   • 
   • And fits perfectly in the gameboy too!
   • 
3. The finished products!
   •