Thanks for all the responses guys. In particular the last one. As it turns out this bevel gear does need to have a 3:1 ratio. The small pinion bevel gear (16 tooth) will most likely be a purchased item, However for a variety of reason it would be preferable to machine the large bevel gear ourselves. In particular I was looking into using a three axis process like this
http://www.youtube.com/watch?v=vw4ZX8VDIqY which is often used to make large bevel gears. Is this process a feasible one ?