[Flieger]

We had to do a (single plane) rotor balance in a vibrations lab I had. The theory was it would take two spins. The first one you spun it up to find the original imbalance, and corrected it for slow roll. We were using transducers that measured the distance betweeen the shaft surface and the fixed transducer. The slow roll correction was done at slow speed and by subtracting that signal from the total at any speed you could see the dynamic imbalance, ignoring the vibration due to any bends in the shaft. So if your wheels are not true that can screw things up if you are not spinning the wheels very fast.

After that we did some stuff that would be way boring for here. We basically added a weight in a spot close to the heavy side (which we determined looking at the graphs from the initial run), then spun it again, saw the effect of that weight, and based on that effect calculated where to put the next weight. We had fixed spots and fixed weights so it was not really possible to get the rotor balanced without a lot of weights. If you want less weight you need to calc the vector sum, yada yada yada.

Basically, you should have a true and balanced wheel to calibrate I would imagine, and do the balancing at high speed. You may need several weights since you have fixed amounts of weight to choose from and you may not put them in the exactly right place.