Building Alert: Construction Issues

We thought and thought about what to use to place over the kart’s works to give our kart a top. In a stroke of genius (well, we couldn’t think of anything else, to be honest, and we were grocery shopping at the time), we used a plastic food storage container to create a bubble-like dome. It’s cheap, easy to work with, and clear so you can see what makes the kart go, which is kind of cool. Make sure you get a container made of flexible plastic. Flexible plastic is easier to use because you have to make two cuts in this container: an opening in the back that lets the IR signal from your transmitter reach the IR detector in the back of the kart and an opening in the side so you can reach the power switch.

You can build the base of the kart out of 14" thick plywood or 14" rigid expanded PVC (plastic). The PVC provides a better finished look than the plywood, but either will work. You should be able to locate 14" thick plywood at any lumber or homebuilding store.

A couple of robot supply houses, such as Budget Robotics and Solarbotics (here the material is called Sintra), sell small sheets of rigid expanded PVC. A Google search for “rigid expanded PVC” will also turn up plastic supply companies that sell larger sheets. Find more at these Web sites: www.budget robotics.com and www.solarbotics.com.

If you don’t feel ambitious, you can leave off the bubble top and let the gokart be a convertible model. If you plan to reuse the components after trying out the kart, that might be the way to go. However, if you plan to keep the kart intact, we suggest that you use a top to keep out dirt and avoid the possibility of wires or components being knocked off (in case your kart gets into a traffic accident in your living room).

The motor lugs used in this project are made of thin metal and will break off if you put too much stress on them. By using stranded wire, rather than solid wire, you can minimize the stress on the lugs.