The Art of Engineering a Science Project

My year has started off with a few community service projects for BICAS. The first is with a Jr. High student (St. Michael's, Tucson) named Max. Max wanted to make a bike with a fan powered sail! Even though I'm pretty good at design on the fly, I'm not able to defy physics, do the impossible, or send off a kid with something that will surely cause an accident or injury. That said, we talked out the options and decided to make a land yahat, sand sailer, blow cart, or whatever you want to call a 3 wheeled sail powered vehicle. To keep the thing light, we opted for state of the art, used metal bed headboard, for the frame. For the seat, a old Prop 201 metal sign. The bmx bike frame welded to the front for steering has a fork for a 26" rim on the front with a working v-brake. The rear wheels are 20" rims with 2 rear triangles from old bmx bikes. The steering is rope assisted by derailers made into pulleys and a couple of store bought pulleys. The mast is a headset and solid steel schwinn fork and headset assembly in a little different configuration than intended (!), with a derailer pulley to hoist the sail. The sail (black, gray, and white camo) is 5 1/2' tall x 3' on the bottom and grommeted. The mast is able to swing from side to side without hitting the rider. We decided to not make the sail larger because of the wheel size being much larger than most of these types of designs. It should go way fast enough for a 15 year old on a windy day, in an empty parking lot! This is the first project I'm aware of that has been done at BICAS for a student science project for a school science fair. I hope it's something that can be done on a regular basis with all kinds of different things that students dream up!