What's the most important in 7-inch quadcopter drones? Thick arms and big motors. Forget about 4mm arms and the
motors we use on 5" quads only with lower KV. It does not work like that. 6mm arms in absolute minimum - we need
stiff arms that are not resonating in flight. Motor size 2208 is the minimum (you might try with 2207 but it
might not work the best) but the fun begins with 2506 and peaks at 2507! In terms of KV, for Long Range Cruisers
300KV per 1S works best (around 1200KV on 4S). For freestyle 400KV per 1S (1600KV on 4S) unleashes the fury!
Like my Alfa Monster with 7-inch arms and Brotherhobby Avenger V2 2507 1750KV motors on 4S. A shitload of
torque, power and climb rate! Full specification: