szempruw

I had already determined that I wanted the switch up front near the batteries. I searched the internet for ideas on making a hatch. I found some good ones by expert builders, but one concept offered was a rotating door using a wire and a tube for a hinge. It was a simple concept where you’d push on the bottom (or top) of the door, and because it was offset, the door would rotate open. I liked that idea. I implemented that concept which was only a diagram and used a piano hinge and magnets to keep it closed instead of a latch mechanism. Here’s what I did to hide a Miracle Switch with charging ports for my LiFe batteries.

I picked a location where it was easy to cut through the fuselage and to hold the switch box that I would make. I made sure the switch box would sit on the motor mount box that I made for my motor mount. You’d have to go back to post #4 to see how I mounted the engine.


The switch box is made out of 1/8” plywood and is roughly 3 ½” by 1 ¼”. I built the 4 sides supporting them with triangle stock. I then sized a plate. I first hogged out and fitted the switch. I glued the plate to the edge of the box. When the epoxy set and after sanding the box square, I used a band saw to cut the box in two pieces allowing enough clearance to recess the switch, about ½”. I then glued the cut off piece onto the back of the plywood plate to rejoin the box. This seemed easier to me than making two independent boxes, but that’s up to you if you copy this. The door is offset about ½” which was just a guess on how much push I would need to open. You have to watch out for the way the piano hinge rotates and also drill extra holes to offset the tiny screw heads from hitting each other. Here’s where I thought of using large steel flathead screws instead of opposing magnets. One wasn’t strong enough so I placed in a second magnet and wood screw. Later I found out how that really turned out to be a good idea and helped me which I will explain later.




I checked for fit into the fuselage. I had to cut out some of a shelf I installed earlier and I mounted the switch box securely with epoxy. There were large gaps around the edges so I installed 1/32” plywood strips to form a clean and solid frame that fit to the hatch door.


I used light weight epoxy putty to fill the gaps and sanded the frame flush to the fuselage



I used some of the putty to stabilize the long screws I used. Here is where the screws work out nicely. The door was uneven with the outside of the fuse. I was able to adjust the screws out till the door was fairly parallel to the fuselage. This was a chance happening. I wish I could claim I thought about this in advance, but this technique really minimized the filler I would need to make the door flush with the fuselage.



Soft balsa stock 3/8” was used to plank the plywood door


I spackled any low spots before glassing the door to make it a hard surface.



I tried to make the door and fuselage gap as small as possible, but note that the larger gap at the top (actually will be at the bottom) which had to be rounded slightly to allow rotation. The door shuts nice and solid and is easy to open.



Overall I think it’s a good concept. I like the idea of not having a latch. This looks more scale even though it will mess up the panel lines. Again, "Pseudo Scale." I wish I could find that post again to give credit to the poster.