First attempt at making a 2 piece mold for the track pad and link bolted together out of a plaster cast. Since I don't have a cnc machine.
I was not sure if it was going to work and it didn't. It failed and cracked. The plaster it still slightly pliable after it sets(30 minutes or so) so I thought I might be able to slide it out ok. Even if I had added more water to soften it even more. The undercut on the track pad still would have deformed the mold. It was just a test anyway to see how the whole process goes.
The search is on for other methods. I'm considering lost wax, lost foam, or prototype metal mold casting. I will find a way to get this done. 102 track pads to go.
![](http://i784.photobucket.com/albums/yy130/jp7986/2012-10-19_03-09-20_639_zpsa10d0050.jpg)
On the left side mold. On the bottom of the track pad is where the undercut is. That's where it cracked on me. Also I forgot to make a sprue or vent holes.