A Reliable Cargo Bay Door Open and Close System

I've been flying the FT Guinea Pig for awhile now and am LOVING IT!  During the build I also worked on a reliable way to open and close the cargo bay door.  I had a set of retracts from a Durafly plane that never worked right.  That plane was gutted and I'm glad I kept the retracts.  They were perfect for this application.  All you need is:

An electric wheel retract

A piece of thin plywood

A strong magnet. 

Installation is a breeze. 

1) The wire from the retract is shortened and bent up at the angle of the cargo bay door.  This is the hardest part of the project.  Take your time to get the angle correct.  Be careful not to bend the wire too many times as this weakens the metal and can cause it to break. 

Here is a rough drawn schematic of the assembly.

2) The retract is hot glued to the plywood.  The retract is not glued flush to the cargo bay but rather is glued hanging over the edge of the cargo bay door opening so as not impede the movement of the retract wire. I used a piece of plywood slightly larger than the retract but when I build my second FT Guinea Pig, I will used a longer piece for better stability. The plywood is glued hanging over the opening of the bay door by a bit (thats a scientific measurement).  The retract itself is actually hanging over the edge so that when the retract wire is retracted, it doesn't protrude through the lower wall of the plane.  

3) When the retract is not retracted, mark this location on the bay door. 

4) Trace the shape of the magnet onto the foam.  

5) Dig out the foam from this area to match your magnet so that your magnet is flush with the cargo bay door. Install the magnet with hot glue. 

5) The last step is to cut a groove in the bay door in the path of the retract wire by the hinge.  This groove is about 2" long.

This picture shows the groove carved into the door, the plywood placement, how the retract is hanging over the edge so it doesn't impede with the retract wire and the magnet installation. 

Here is a picture of the retract I'm using.  Disregard the popsticle stick at the end of the retract with the prebent wire.  This was my version 1 but broke free on the first use.  Thats when I decided to use the magnet which has worked flawlessly.

Note that when full retracted, the wire doesn't meet up with the magnet.  It only meet up when the door is closed.  Air movement pushes the door back up so the magnet will meet up with the retract wire.