HeloFan,
The first page is the basic theory demonstrating how force is produced. Page two demonstrates how to produce a consistant constant force, however there is an unbalance between A and B which is rectified on page three. With each reaction weight being paired to one reaction weight of another pair 180 deg out of sync spinning in the other direction. The two additional pairs also accelerate and decelerate in the same manner as the first two bringing the total number to eight.
Regards
Jiff