I read the "Electric Motor Handbook" from Astroflight. The book explains the basic physics of hobby-motor operation, but there is only a 1 page discussion on brushless motors. This left me with many questions.
According to the book, brushed-motors have greater efficiency at lower (high-load) rpms, whereas brushless motors have greater efficiency at high (low/no-load) rpms. Is this still true?
The book doesn't talk about magnets (gauss) and their effect on motor performance. All things being equal, does a stronger (cobalt) magnet increase efficiency, or does it just increase the power-dissipation through the windings? And what is a "wet" magnet (I see that term in advertisements for RC/Car stock-motors)?
My last question is more of a motor-design question than anything else. The book's graphs show various plots for Astroflight's product-line (circa 1994.) The common trend was smaller-sized motors had *higher* no-load RPM than the larger-sized motors. Is this a freely-made decision, or was there a conscious trade-off/compromise involved in choosing the Kv constant?