[DonRotolo]

The issue with bevel gears is that the teeth (and spaces between them) are not constant - they taper. Some careful clamping and indexing can help get the blank aligned with the cutting tool properly, but you need to use a tool that is narrower than the narrowest space and let it run its path. A specially-shaped cutter is best, tapered so it cuts the flanks of the teeth properly.

Get a bevel gear - any - and study it to plan out your buts. Make a few from wax or aluminum to get the feel and plan out the holding and indexing.