Originally Posted by arbilab
The notion of an adequately-sized tailmotor inboard where its bulk can stay within CG, is very attractive. But ever since my Erector Set days I've been skeptical of bevel gears. They work fine in car differentials, but those are helical AND submerged in goo.
Exactly. Hirobo made it work by using a very good quality coreless motor, foam rotor blades that don't weigh anything and a drum and pinion gearset that has very little friction. These are details Walkera missed.