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installing electronics

Ive made lots of balsa kits before. But never installed receiver or servos in a balsa airframe before. At whut point should I install them and how do I compinsate for the cg? I'm makeing a 50" minoimoa it wus never intended for Rc. Just a free flight hi start.any help would be grate. I have to go to work so I wont be Abel to get back to check back till later sorry


Hostage Taker of Quads
Staff member

no worries, it's a forum, not a chat ;)

Neat idea! Been thinking about something similar w/ foam, but stick-build planes have far more charm!

I suppose you need to start thinking about it before you assemble anything a control surface will go on. If the wing or stabilzer layout can tollerate cutting a notch and adding a surface, it can be left utill after the assembly, otherwise you'll have to design it in.

If you go simple, rudder and elevator control would be easiest. You'll have to "hinge" and mount the control surfaces prior to mounting on the tail and mount control horns near the root, but with clear movement (Rudder on one side, elevator on the other, all clear of the fuse throughout the throw). You'll likely want to wait until you're covering the tail before you install the linkages -- pop a hole in the covering where it passes through and glue in a peice of tube for a guide -- that way you don't have to cover around your control rods.

If you must have ailerons, consider mounting one in each wing on the bottom, near the CG line, and cut the ribs and frame around it accordingly. keep in mind, it needs a secure mount, but you might want to get to it later to repair/replace.

Assuming the model is neutrally balanced by design, and since this is a glider (no motor weight up front) best to mount the servos and electronics it in the center, near the CG. You'll want to do that as you're finishing assembly of the fuse. Also consider adding a hatch or a removable wing mount to get to them for repair, adjustment and battery sawp. If you mount your electronics just aft of the CG, and your battery just forward, you can leave room to nudge your battery forward to finish out the balance.

For the elcetronics, you'll likely want your receiver, 2 servos (the typical 9g servos will likely do just fine), a small 2 cell (200-500mah range) and a UBEC. If you're careful about voltage tollerances on the servo and receiver selection, you might succeed without the UBEC.


Old age member
I would have used generic 9 gram servos for rudder and elevator on a 50" Minimoa. (like HXT900 servos)
Get all electronics between the wings and use strong sewing thread between the rudders and the servos (pull-pull).
The receiver battery in the front to replace the same weight of lead normally used or between the wings if you do not have any lead in the nose of the minimoa.
Use the same high start as you are used to.
I guess that you already have the rudder connected to the hook release and only have to replace the spring on one side with a thread.
I assume that you can modify the fuse mechanics (elevator)with a servo somehow. You only need a very small amount of movement on the elevator (stab).