Sabre Weight Analysis & Ballast

Since I first measured the components and parts of the Sabre, it has gone through so many iterations of small changes that I can't quite capture everything.

I finally got around to the tedious task of re-measuring all of the components, as well as the important (and previously not done) task of laterally balancing the wing.

Since the 1.3 GHz video transmitter is so much heavier out on the wing when compared to the 5.8 GHz one I was using, the lateral imbalance was enough to warrant correcting it. I did this by adding coins to it until it balanced, and then carving out a clean hole in the left wingtip to hide the weights away.

I actually made up a process for making the opening, at the right size and depth. I started by tracing the outline of the weights. Then I measured the depth I needed for the set of coins to be flush or slightly submerged under the surface of the wing. I put a wrap of tape on the Exacto at this depth, and cut a grid out of the foam inside the outline of the desired opening. Then I used needle-nosed pliers to pluck each piece of foam out of the grid. This process worked really well, and I will likely find applications for it in the future. For the cover of the weights, I simply used a piece of white card stock and packaging tape.

I also had to make a tail weight for use with flights that use the heavier 16,000 mAh battery. This weight is also made with tape and coins, but it is not as elegant as the wingtip weight. I'll just insert it into the hole in the aft part of the fuselage where the tail pieces attach, and secure it with tape when it is to be used.

I created a matrix of the airplane configurations that are possible, or at least probable with all of my current equipment, and used this to calculate the flight weights.

Overall, the plane is about 7.6 - 8.5 lbs with a 5.8 GHz FPV setup, and 7.7 - 8.7 lbs with a 1.3 GHz setup.