It is surprising how poorly most pupils understand mechanisms. Automata are a superb source of solutions to many mechanical problems. The artists who construct these metaphors are some of the cleverest engineers i have met. They solve with simple wood and chains what many companies would produce full electronic servo, microprocessor controlled, positionallay accurate, cost a fortune alternatives.

Many people who make these devices actual make a living selling copies.

At keystage 3 i would place card over all the mechanisms openings and ask the pupils to guess how the mechanism looks inside by seeing how the arrow moves. I would them make a simple automata. The favourite is the two offset (Marked) cams making a head move up and down and right to left.

At keystage 4 i would then add a full design and make of their own automata.