The motors now offered with ARDUCOPTER have plenty of power and are reliable. I only have one issue with them. During the very first takeoff test it flipped from front to back bending the shafts on the two front motors. I tried looking for a replacement shaft how ever even if I found it the shaft on the motors does not come off. I like the motors but I don't want to buy a new one every time I bend a shaft. Has anyone used any other type of motors? I'm thinking of buying something with a name brand that I can find accessories for. Especially a screw on prop drive. As another option I would cut the shaft and screw on a prop drive using the top 4 screw holes. has any one done this or similar? I want to use something like the image to avoid worrying about a bent shaft causing vibration or worst.