You can see the model in action on Instagram here

Here’s a fun little mechanism inspired by this model by master automata maker Paul Spooner.
Starting with a disk connected to a rod, I’ve added four stops evenly spaced around the rim.

The disk then matches up with a stop fitted to the box top. The disk is free to turn in a loose fitting guide tube.

Here’s the clever bit. There’s a drive cam fitted to the drive shaft in the box. The flat surface one one side of the cam allows the disk to drop down a fraction releasing it from the stop in the box top. It is then free to turn but only by quarter of a turn.

The lid is half a millimetre smaller than the box so drops into place with a snug fit.

For each turn of the handle the vertical shaft turns quarter of a turn. Clever stuff!

I’ve added this large arrow for clarity but a whole variety of characters could be driven by this mechanism. What about an owl with rotating head or a watchdog looking round and round? I’ll be releasing the mechanism on its own shortly then adding my own character to make it into a complete model. Betcha can’t wait!

If anyone knows the name of this mechanism I’d be interested to hear, please leave a comment and let us know.