Hmerly

How do you compare brushless motors? Aside from looking at kv, what other factors help determine relative performance? I've been looking at different motors and realized that I really have no clue what specs to look at to determine if one motor is going to provide more thrust than another or if one motor will be more efficient than another. Anyone help a noob out here?

Dr Kiwi

Motors don't supply thrust... propellors do.... so you first need to determine what size prop your aircraft needs (larger diameter gets you more thrust) and what sort of power you want to use (based on the rule of thumb of say 100W/lb for gentle flight, up to 200W+/lb for all out aerobatics). You then choose a motor of appropriate size to cope with that amount of power (3W/g is a useful rule of thumb). Deciding on Kv will depend on what size prop and what voltage you intend to use.... which in turn depends on whether speed or thrust is most important.