While researching PIC-based ESCs, this material was discovered.

How to make an ESC without a PIC © 1999-2002 Szydlowski
Robert
Get an old servo where the servo amplifier still works. Cut off and remove the
motor from the servo but leave some wire from one of the cables leading to the
servo motor. Connect this cable to a 500 ohm resistor. Then connect that to the
GATE (G in diagram) of the MOSFET. Find the negative wire of the servo which
leads to the receiver, solder some wire onto it and connect that to the SOURCE
(S) of the MOSFET and the negative port on the battery for the motor (note: this
is not the battery for the receiver). Then connect the DRAIN (D) of the MOSFET
to the negative port on the motor. Then connect the positive port of the motor
to that of the battery. When using more than one MOSFET, use a separate resistor
for each one (see diagram below).

Notes by Ironsides
Note:
G = Gate
D = Drain
S = Source
The load (motor) is on the DRAIN
The MOSFET used in this example is the IRF530. An IRL2203N or IRL1404
would be a better
choice, but harder to find and more expensive than the IRF530.
