Rotary Club Technology Challenge
Squashed Tomato Challenge (Practical Action)
Rube Goldberg Machine (Also see- https://youtu.be/qybUFnY7Y8w )
Automaton Challenge
Steampunk Mechanical Challenge
Robotic Prosthetic Challenge
Battlebots ( https://battlebots.com/ )
Custom VANS (Also http://mrkimble.weebly.com/vans-shoe-comp.html)