Three-pendulum near-unison results
The effect of the 3rd rotary pendulum increases the variety of possible results. Some of the best designs occur when the three pendulums all swing at similar but slightly different frequencies, with the rotary pendulum swinging around in a circular motion. Note that the mass of the paper platform on top of the rotary pendulum causes it to swing at a slightly slower frequency when all weights are at their lowest position, so you would raise that one slightly if you want it to match the frequency of the other two.