Lifting gear has been converted to a hub, bearings, and spokes to statically balance the rotor. Adding 45 grams has made the rotor reasonably well balanced. When spun it will stop in fairly random locations. There is a copper tube ring fitted, 10.9mm internal diameter with a volume about 0.66 litre.
This is for dynamic balancing. It is held in place with clips as shown, and also silicone sealant, and is located in the angle of the stiffening ring. It has a small filler plug. Mercury
can be used as the balancing medium, or small bearing balls in oil. I will probably use 50gm of 3/32 brass balls (non magnetic) in 50gm of moly oil to start testing.