I spent a full day this weekend working on a casting project for a 50 year reunion medallion. I have been working on this project for at least six months trying to create a mold for casting for what will be hundreds of medals.
I have the design but I have been experimenting with how it should exactly look. I have drawn it both in Vectric Aspire and Rhino. Aspire has been the easiest. The big problem is making a mold that can withstand all the casting. I want to cast them in pewter.
I can make perfect versions in blue wax using 3D CNC. The run time is between 3 to 4 hours. There is usually 250,000 lines of code. I haven't been so good at machining aluminum. It's probably because I am using the wrong alloy for making the fine detail I want. Eventually I'll get the aluminum mold figured out as that is my preferred method
I have some pictures and video of the processes I have been trying. I don't want to publish until I have something that works perfectly. I first tried some high temp RTV (red) casting rubber but I think I got the mix wrong. The rubber didn't cure quite right and seemed to out-gas when I poured hot pewter into the mold. I switched to making aluminum molds which works, but like I said above, I am having problems with the detail machining.
I am making another rubber mold from the wax master I made this weekend. The cure looks good this morning.
