Neither you nor anyone else can touch nor interact with your machine during operation. In other words, it's a completely hands off operation. You push the start button, then stand back and enjoy watching your creation do its thing. At least one of the machine's actions must be easily visible from 10 ft. away. Must be resetable for the next run in 60 seconds or less.
Human intervention is permitted during the reset period.
Must have at least one part that moves. Must be completely self-contained, including power sources. Only batteries can be used as sources of electrical energy. Nothing can connect to the 110V power line. Must be safe for operators and audience.