Rope balancer D-BP with a KBK system (via)

The balancer in the photo uses magnets from a Top Flight Prop Balancer and works the same way. The shaft is a No. 54 drill blank with one end ground to a point, and the frame is made of wood.  Music wire of 0.055 in. diameter would also work as a shaft, but would not be as accurate.(via)

Ours, balancer (via)

with a piezoelectric ceramic sensor to provide more accurate measurements (via)

A CG balancer is included with the Reactor Bipe, so that you can properly set and balance your model to match your flying style. (via)