[asid61]

We have a digital protractor that we use for odd things like that, and a vise that can turn. Even if we had a sine plate, I doubt we would ever use it; this year our 1x1 back braces for our elevator needed a 43.2* angle or something, and we just tilted the vise to within 0.1* and milled it right, and it fit on just fine. We had a plate that needed a 44* angle, so we tilted it in the vise and got a reading to within 0.1* with a digital protractor.
That being said, if this is a learning exercise for your veteran machinists it will teach them a whole lot of stuff, and it sounds amazing. I look forward to seeing hoe this goes. I was very impressed with your power-fed rotary table welding this past year.