Input: blue shaft.
Angle between blue and green shafts is 40 deg.
Brown barrel has complicated motion.
Blue and green lines are loci of center points of the barrel end faces.
Orange and violet lines are loci of peripheral points of the barrel.
Strange things are:
1. In 1 rev. of the input, the peripheral points turn 1 rev. but the center points turn 2 rev.
2. In 1 rev. of the input, the green shaft turns 1 rev. but reciprocates twice.