This was a fun prop made for Chitty Chitty Bang Bang. Caractacus Potts invented a haircut machine to make some money at the fair so he could buy Chitty from the junkman. The machine is supposed to malfunction and start smoking as it burns off Sid’s hair!
This machine had to be safe for a kid to wear on their head, fairly indestructable, and I had to throw it together on a very short timeline.
It's powered by 4 AA batteries, stepped down to to USB outputs which feed the two USB-powered personal ultrasonic misters. The misters are designed to be set into a bottle for continuous use, so I had to seal up the filter cases to act as self-contained water resevoirs, and I hacked the push button for the misters into a wire I could trigger with an Arduino Nano so that both misters would go off at the same time after a set delay. The rest of the hat is just spraypaint and spare parts – very very simple prop.