Ever wondered about the difference between DC, coreless, and brushless servo-motors? This askJOHN article addresses it in a largely brand neutral way. and is generically useful because all servos - regardless of brand - use one of these three types of motors (share the link freely).

Is your avionics battery pack safe for three-flights? How about five? How can you figure out if it's safe to fly a sixth time before recharging the battery pack powering the radio system? The answer determines if you drive home happy at the end of the day, or not!