Designed for models that have electric retracts and gear doors, this circuit will allow you to sequence the action of the retract controller and gear doors for proper timing and operation.  All the functions of this circuit can be adjusted to make it customizable for almost any model, including the direction (up or down) of the signal sent to the retract controller, the delay between the cycle of the controller and the movement of the gear doors, and whether or not the gear doors remain open after the gear are down, or close back up until the command to raise the gear is received.  In addition, the speed of the gear door servo is reduced for more scale-like movement, and to make the timing of the functions easier.  Plugs into a single channel in your receiver, and connects to both the retract controller and the gear door servo(s).  Can be used for multiple gear door servos by using a common servo Y.  Check the Product Details section for a description of a typical installation.


Small, compact, and easy to set up, this is a great way to solve the problem of gear door sequencing without having to use multiple channels in your receiver and/or complicated programming of your transmitter.


UPDATED VERSION: This circuit is now available in two versions, the original version that is suitable for retracts that are driven by a conventional (proportional) servo, and a new version designed specifically for retracts that are driven by small, brushed DC motors, like those that come pre-installed on many ARFs sold by companies like FMS, Robart, and E-flite.


DOWNLOAD: Electric Retract & Gear Door Sequencer Manual

Electric Retract & Gear Door Sequencer

  • Weight:  12 grams

  • Note: The programming of this device has been updated to make it compatible with some of the retracts now being shipped with models made by FMS, E-flite, VQ, and other manufacturers.  Some features have been removed, some added, and some re-designed to make setup easier, to make it more "fool-proof", and to make the unit function properly with some of the smaller retracts that do not use separate "controllers".  A new, updated Instruction Manual is avalable for download using the link on this page, and in the 'Manuals" section.


    All of the "options" offered by this circuit are controlled from the main circuit board.  The two red Option Switches are used to select the option of closing the gear doors after the gear are down, and the direction of the rotation of the gear door servo(s).  Switch #1 is used to determine whether or not the gear doors will remain open after the gear are down (P-47 style), or will close after the gear are down and locked (P-51 style). Switch #2 reverses the direction that the gear door servo rotates (clockwise or counter-clockwise), to make mechanical connections to the gear doors easier.  The small blue trim pot located on the circuit board is used to adjust the delay between the time the gear begin to move and the gear doors begin to close, which allows for the different speeds that may be encountered on different retract systems.  Since a microprocessor controls all of the unit's functions, the retract controller will never be cycled until the gear doors have completed their movement, and until the delay for the movement of the gear has expired.


    Detailed instructions are, of course, provided.