I have been flying electric for about a year or so, and i have flown a gas plane twice. But now im starting work on a SPAD plane and i want to know about servos and crystals are - i basically know what they are, but i want to actually understand their purpose and stuff so that i know what im doing when i start building. does anyone know where theres a good site that explanes? Maybe with alot of pictures...everyone loves pictures! Any, if you know of a site please let me in on it.

-Fox