Robot Repairs

This cute little robot found his way back to my workshop this afternoon. I made him about four years ago for a game at One Way Out escape rooms in Oakham. This time he had a problem with slightly loose battery connection so I replaced it with a fully enclosed battery box (4xAA) so hopefully he'll be fine for a bit longer. It made me realise I'd never talked about the insides. He actually has a twin brother who occasionally visits too and they both get upgrades over time. The robot is put together during the game so the parts essentially hide inside a larger box.

The main change would be in the arms of the device. They were originally phono connectors which on the surface appear pretty sturdy but after a couple of rushed attempts to assemble the parts while the time is running out on the clock those had a tendency to break off. The solution was to remove them entirely, the shoulder joints are now just metal pins that insert into appropriate sized holes. There's a magnet right at the bottom which draws the pin in and snaps it into place. A simple microswitch is depressed as the pin enters the tube and detects the connection. It's much more rugged that relying on an electrical connection looping through the plug/socket.

The head detection works on a very similar principle. I've never had any luck with reed switches, they seems to need perfect magnet placement, occasionally get stuck in the on position, and don't like being dropped so I decide to not even risk it. For this box there is a free floating magnet in the top enclosure, the matching magnet from the head pulls the magnet towards the back of the box where it presses against a microswitch. It's been one of the more reliable parts of the build.