Maybe I am just a geek a heart, but it seems that I am continuously amazed by technology. Burt21 over on the H.A.M.B. contacted me to draw a CAD model of a fuel block that he wanted to eventually cast in aluminum. We talked about possibly machining a female mold that his foundry man could use to make a male form from. I suggested that we try this place:
The surface finish didn't turn out too bad. There will be some hand finishing required, but should turn out really well. Apparently, the process prints every 0.010" so you will not be able to get a perfect part, but still, I am impressed.