Recent advances in remote control (RC) modelling technology allow the average hobbyist to explore a wider range of aircraft with detailed scale features. Mechanical retracts are highly desirable as they allow an aircraft's landing gear to be pulled up into the fuselage during flight (just like on many full size planes.) This not only adds to the model's in-flight realism, but also significantly reduces drag; allowing it to fly faster and longer on a single tank of fuel or battery charge. This is especially useful for jets and warbirds, which make use of speed and sleek lines to attract RC enthusiasts. Once solely the domain of experts flying expensive quarter scale planes, mechanical retracts are now available for nearly every type and size of model plane.
Install the retract servos between the mounting rails near the front of the wing toward the centre.
Form an axle at 90 degrees to the strut, 11 centimetres from where the strut projects from its plastic mount.
Attach a wheel to each axle with a collar. Use Loctite on the thread for better hold.
Separate and remove the fixed landing gear assembly from the wing mounts.
Cut away some plywood on the coil side of the opening for the strut. This will make room for the landing gear coil.
Apply black marker in a line around the edge of the landing gear mount openings.
Connect a 6-inch length of twist tie (using tape) to each of the retract servo's pushrods.
Insert each of the pushrod wires into the openings where the fixed landing-gear mounts were removed.
Orient each strut's coil toward the rear of the wing and connect the pushrod to each retract's activation rod.
Slide the retracts into the landing gear mount openings and use four half-inch screws to attach each landing gear assembly to the wing.
Push the control arm onto the retract servo's output shaft, and tighten the control arm to the retract servo.
Bind the retracts to the gear switch on the transmitter, and cycle through several times to test final operation.
Prior building experience is recommended. Instructions are for typical installation on a WW2-era low-wing design plane. Fine-tuning may be required for exact fitment and operation. Metal gear servos are recommended for increased strength.