Note: There are deffinately things I would change with my design if I were to do it over. Financial considerations played a big role in some of the steps I took. Please feel free to critique the design. If I decide to make another one I will take all ideas into consideration.
Castin Craft resin (alot)
Castin Craft catalyst
26 gauge sheet metal
1/2" steel tube
AWG 3 point tool belt shoulder straps
Double stick tape
Bicycle safety lights
Step 1: Plumbob form
1) I used 26 gauge sheet metal because I am a sheet metal worker by trade and I am used to working with it. There was a two part mold for EACH HALF of the 12 sided diamond. I made two 6 side pyramids.
2) After looking at the SIMs literature that comes with the game discs I figured that the plumbob has a height to width ratio of about 3:1. I didn't do any fancy trig calculations to figure the angles out. With a piece of paper and a compass I played with some dimensions until I came up with a size that looked right. The dimension I cam up with was a form the has 2 1/4" base widths and 6 1/2" centerline height.
3) Knowing that this was going to be a form that was to be filled with a liquid I then extend the form height a little and scored a line where i would be filling the resin to, so that none of the resin overflowed. The picture describes the basic layout of each half of the mold. When bending the metal it is important that you measure the angle of the BOTTOM of the pyramid to 120 degrees. NOT the angle between the two flat sides. Put the form upright on a flat surface and lay a compass down next to it.
4) There are two 1 inch flaps on either side so that there is something to help clamp the two halves together. I applied some silicon to each flap and clamped them together. The silicon was mostly to prevent the liquid resin from running out of the mold.
I'm sure there are other ways to make a mold this shape but I went with what I was familiar with. Also, once you add the catalyst to the resin it gets really hot. I figured the metal would handle the heat well.