As promised, here is part 1 of our series on motor and propeller theory. Part 1 covers the coil magnet model, Kirchhoff's law for a motor, Back EMF, Kv, Kt, and motor efficiency.
By the end of the first video, you should really understand why is a motor is inefficient and the relation between electrical power, heat and mechanical power. The motor model is constructed part by part. I tried making this series different by giving a lot of examples while being backed by a solid theoretical background. We have more tutorials on our website. If you have any question or comment, my colleague and I will answer questions!