wow, thats crazy that you said that because ever since i've had the aluminum heads ive took two teeth out of two gears already. and i bought it just to upgrade for fun. only thing ive ever really broken is blades, landing gear, and a body. i was sick of buying a pack of rotors every week so i said f**k it and just bought 20 packs for $80. now i just need to find a gymnasium to fly in.