My Fourth Automaton (Acrobat)

This automaton was the most complex of all the five pieces. It had an excellent movement. The acrobat would balance on a table and chair. He would first slowly raise his body up then down. He would then raise his body higher a second time, followed by raising the chair into the air. He would tilt his balance to the left hand in doing this. When completed, he would lower the chair and his body to the original position.

The figure was knocked up from plastic spares. The rigid body was articulated only at the shoulder for the two arms. The left shoulder was the most important. There were two tiny holes next to each other. Wires were fitted into these holes. One wire acted as a pivot for the left arm. The other wire was fitted to a follower for the cam located below. These closely juxtaposed wires allowed for sweeping movements of the body with very small displacement of node points. The joints were further disguised by puffed up sleeves. The left arm was fixed to the table for support. The right arm was attached to the chair to raise it.  One cam was positioned under the right arm to make a single lift.

The main body was lifted by a large cam underneath the left arm which turned slowly, allowing for two lifts. The apogee of the movement had the cam pushing the rider up, incidentally causing the unexpected tilt, resulting in a very pleasant movement. A little necklace was allowed to swing freely to add further interest.

The box was made of cardboard, decorated with pictures and mounted on a simple wooden base. The exposed mechanism shows the musical movement connected to a Tamiya gear mechanism which was used to slow down the turning movement.

I had used cheap plastic bricks then to ensure true alignment.

Looking back at the construction, I should not have used cardboard for the box. This is not a durable material. The cheap bricks occupy too much space within the narrow confines of the box. The Tamiya gear mechanism slowed the mechanism by too much. The follower made out of thin wire sometimes bent under frictional forces from the cam, thus jamming the mechamism and preventing movement from going up and down. This was further exacerbated by time and surface rusting on the thin wire. The cams have started to roll around the spindle, negating any possible automata movement until this is rectified.