Date: September 26, 2008

Now I can start with the balancing. I plan on doing the balancing in two phases. The first phase is to determine the location of the main batteries. Once I build a mounting bracket for them, then I can rebalance, using the receiver battery, if needed, to get a final balance.

First I assembled the bird, and put it on the balancing stand. The CG is underneath the main wing spar. When it first set on the stand, it was tail heavy. But I only had two batteries in it. I plan on using four. So I added two more batteries and started to slide them forward. I didn't need to go far, with the front of the batteries about 3-1/8" inches from the firewall, the bird balances perfectly. (Pictures 1 thru 5)

Next I removed the wing and proceeded to build a battery mount. After thinking through alternatives, I came up with a simple box. The box would be open in the front and the batteries would stack on top of each other. A velcro strip will wrap down the front of the box, holding the batteries in place. In the picture you can see the open front of the box, currently a scrap is being used to help clamp, but some of the top will be open too. (Picture 6)

As I think about it, I like this idea more. I can rebalance the plane, shifting the box forward or back, to get a better balance. I will need to find some velcro strip material.

Picture 1: The plane balanced, the batteries in approximate location.
Picture 2: The plane balanced, the batteries in approximate location.
Picture 3: The plane balanced, the batteries in approximate location.
Picture 4: The plane balanced, the batteries in approximate location.
Picture 5: The plane balanced, the batteries in approximate location.
Picture 6: The beginings of the battery box. The front and part of the top is open.