Petersi - you've been given good recommendations here. Machine the pieces instead of making an injection mold. For the quantities you require - this is likely the cheapest, fastest option.
I figured at an 8 sec cycle time on a single cavity mold (not including the cost of the mold), you'll be...
Have you considered a plastic injection mold with interchangeable inserts made of aluminum?
Cost wise it won't too prohibitive compared to other ideas floated. Your cost is going to be fairly high regardless which way you go as you have 20 different patterns.
If there is any chance that you...
We use WebEx Meet-Me-Now to do demonstrations, online training, and support of the mold quoting software we sell. We are often using 3D models, rotating, sectioning, etc and there is seldom an issue with viewing.
This has worked very well for us, even though we are using the 'lite' version...
