Electric > Motor Sizing

Q-2: An old-time glow-fuel pilot mentioned that for years he referred to engines by their classes, such as Class 1/2A, Class A, etc. Each class had a specific engine displacement; Class A was understood to be .10-.199 cubic-inch displacement, a .19-powered model was supposed to weigh approximately 19 ounces, and so on. He went on to write that with Electrics the identification of motor size to model size is difficult, to say the least. He cited examples of Speed 280, Speed 400, etc. How do you decide on application? Answer ...

Q-44: I’m an experienced modeler who has flown strictly glow-fuel-powered aircraft. I always knew what displacement engine would power a particular size and weight aircraft. Now I’m entering electric power and I’m having trouble relating motor designations, motor current, number of battery cells in a pack, propeller size, and whether or not I should use direct or gear drive. Can you steer me in the right direction? Answer ...