Retract Gear and Accessories
MK-20 Retract Gear System
The MK-20 Retract Gear System was designed to meet the needs of models in the
17-30 lb. weight range. It had to be light enough for ducted fan
applications and tough enough for scale models operating from rough grass
fields. It is hand-crafted from aircraft grade aluminum with an emphasis
on simplicity of design and ruggedness.
The MK-20 operates off compressed air. The 2-way valve is controlled
by a servo and activates the cylinders attached to each individual retract
gear to either retract or extend the struts.
All of the gears are mechanically locked down and pressure held up. By
eliminating the need for up locks and holding the gears retracted with
pressure, it allows the modeler a variety of installations possibilities.
Many variations in strut geometry require less than 90 degrees of strut
travel. It is possible with the MK-20 System to stop the gear
retraction wherever desired by
merely adding a stop in the wheel well.
The actual weight limitation on the gear is
somewhere around 30 lbs. of aircraft weight, but this largely depends on the
strut length, field conditions, and ultimately piloting techniques.