From what I've read about other members and their experiences with the manufacturing process, it can be difficult and really expensive. Basically, you're fighting two battles: the process itself and the cost. In some cases, so many parts would have to be sold at a reasonable cost that you 1) lose money, 2) break even, or 3) you can't sell enough parts to even do the first two if that makes sense. With 3D printers, they can help with the process and the cost but it obviously depends on what you are making. In any case, I'm rooting for you and I certainly expect to pay a pretty high price for some clear lenses. I'm okay with that.