I'm trying to figure out exactly how that cam works.
I'm guessing there is an optical or mechanical switch which reads the part which sticks up (to end the chicken's turn and make the chicken make the 'finished turn cluck'), the depth of the cut of the cam controls when the chicken 'pecks' (due to the cliff/falloff at one point; the chicken itself appears to be mounted on a spring, and its head on a second spring, so it pecks forward when the cut suddenly gets deeper), and the distance from the center of the cam controls whether the chicken is facing right, left or centered. In several youtube video it is obvious that the switch did not properly activate (or the cop421 ignored it being activated) on the first full rotation of the cam, so the chicken repeated its movements exactly and did finish its turn on the second rotation.https://www.youtube.com/watch?v=a-7OAX2hcdQ
<- second turn the cam spins at least twicehttps://www.youtube.com/watch?v=MUAXlo-GwuU
<- second turn the cam spins twice