pic: Mammoth GearBox1

[artdutra04]

If you are going to make those on a regular CNC milling machine, then it would be SO much faster to fabricate by making the outside of the plates square. That way, you can just stick the plate in a vise and mill out the bearing holes and pockets (as opposed to mounting it onto a fixture plate, and mounting that inside the milling machine, then having to mill out the pockets and holes, as well as go around the outside to make the curves...).

Also, if the aim is weight savings, I would lighten the gears well before I would start pocketing the side plates to that extent. All it takes is two operations on a milling machine (either CNC or manual with DRO and rotary table) to make these. Depending on the gear size these can save quite a bit of weight.