Hover Cart

This was the first year I was allowed to participate in Destination Imagination. I was really looking forward to it, and I had a great time with my team.

Last summer, my sister and I made hovercraft and soap box cars during the break.

Hovercraft Summer 2015 from Fred Mannby on Vimeo.

When I showed the hovercraft to my team at school, they were very excited, and some even stood up and surfed on it in the hallway.

Surfing from Fred Mannby on Vimeo.

So, around Christmas time I made a new hovercraft for DI, and started experimenting with it. The Technical challenge this year involved creating a vehicle with two propulsion and two motion systems. At first, we didn't get this. We thought it only needed two propulsion systems, so we made different contraptions to let the hovercraft get pushed by wind and pulled by wire.

We played with things that could pull the hovercraft along.

We made a bike pulley, but the propulsion system needed to be on the vehicle, so we couldn't use it.

We had a hard time getting anything to push the hovercraft. The school was very busy, and we couldn't get access to a smooth floor with enough space to experiment on. It turned out that if the ground was curved, sloping, or rough, it took much more power to push the hovercraft, and a leafblower just wasn't strong enough.

Leaf Sail from Fred Mannby on Vimeo.

We thought a team member could walk behind, and blow into a sail. After all, sailing is a propulsion method. We sent emails asking DI through official channels, and they said it wasn't allowed.

Then we found out that we had missed part of the rules, and had to have a second movement method. I had recently found an electric scooter at the thrift store, so I came up with the idea of dragging the hovercraft as part of a scooter-hovercraft vehicle.

To control the scooter, I used the controller from a gokart we bought at the thrift store earlier, because the controller in the scooter would only turn on if the scooter was already moving, as a safety feature. I also made the cables longer, and added a switch that could make the motor turn the other way, so the scooter could go backward.

It was just awesome to drive. All of us loved to play with it.

But, we weren't sure if the judges would think of it as two vehicles or one. So we started experimenting with combining the two vehicles even more. We tried lifting the vehicle using the hovercraft.

That worked, so, we removed most of the scooter, switching to the motor in the gokart instead, since it was already taken apart, and fit well into my new design.

We always had trouble with the long extension cords that we were using to power the two cheap leaf blowers. It would have been great to use a battery-powered leaf blower, but they're way too expensive for the DI budget, and you can't rent the new powerful ones. Every once in a while, the extension cords would get caught under the wheels, and when we tried to run the gokart motor, it couldn't climb over the cables, unless we were already moving. And, I had used audio cables for some of the wiring for the gokart controller, and they melted when I tried to drive when stuck behind an extension cord. It made a terrible smell, and lots of smoke, but luckily only the wire insulation was destroyed. The gokart controller still worked!

We also had a lot of trouble making the gokart go backward and forward. In the gokart, the chain was pushed by a spring, which worked fine as long as the motor was only turning one way. But, if it was turning the other way, the chain would easily pop off, and I at first wasn't even trying to use the spring because it was hard to set up and put in place. Just making the whole setup tight, and easy to take apart and put back together again worked well enough.

The new hover cart was also a lot of fun to drive!

Hover Cart from Fred Mannby on Vimeo.