In your post about making your own turning material I wonder if this is acrylic clay? I have been working with it but not having very good results. Are there any techniques that you can share? I cannot get it hard enough to turn. I know the craft people use it but not sure about the cooking temps and that sort of stuff.

I never got good enough results with the clay to move any further with it. JP Timberlake gave it a whirl as well and like me, he didn't feel it warranted any further work. It's not really suited to the hardness required for turning parts and pieces for rods. At least within the confines of what we were able to accomplish with it. If you've got a good supply, keep at it, but expect to go through a long and trying experimentation process to get anything worth using.

There is a new method which we'll outline in the pages of the upcoming RodMaker that allows you to create your own turning stock from a multitude of materials. In many ways, it will unshackle all the turners from having to use what the pen making supply companies offer. Most anyone should be able to do it. It's a very exciting new technique.

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Has anyone ever used stereolithography (rapid prototyping) to make either parts or patterns for molds?

Not for rod building, but I have used lots of rapid prototype parts in my engineering day job. I can’t see too many rod builders using rapid prototyping due to the high costs, first to get an accurate 3D model, then the cost of the rapid prototype parts themselves. But for a manufacturer, to make a few $3,000 prototype parts before committing to $250,000 in tooling it makes all the sense in the world.