Analysis
the day before testing, we didn't know how far the car would actually go. In the basement that we tested it, it hit the wall and we didn't know how much further it could actually go. so, on the day of testing, there was a problem that we didn't know about completely that made the car go backwards a the end of its trip, taking the total distance and subtracting about 5 feet from it and eliminating any possible coasting distance.
the build process
at first, we were going to make a much bigger, more complicated car that would have two stages of mouse traps. AFTER MANY TRIALS AND TRIBULATIONS, WE FOUND THAT THE BUILD WAS TOO COMPLEX AND ONE MOUSE TRAP DID NOT PROVIDE ENOUGH FORCE TO PUT THE CAR IN MOTION. AFTER SCRAPPING THE FIRST PLAN, WE DECIDED TO MAKE A SMALLER CAR SIMILAR TO THE ONE WE MADE IN OUR PROTOTYPE PHASE. EVEN THEN, THIS CAR NEEDED TWEAKS AND CHANGES THAT WERE EVENTUALLY WORKED OUT, AND OUR CAR BEGAN TO WORK. THE FINAL CAR WAS PUT TOGETHER IN ABOUT AN HOUR, AND TESTED SPARINGLY. HAD WE NOT FOCUSED TOO MUCH ON A CAR THAT DID NOT END UP WORKING, WE COULD HAVE TESTED OUR ACTUAL CAR MORE EXTENSIVELY.
how the car worked
Our mode of power was a mouse trap with string wrapped around the back axle. There was a dowel rod attached to the mouse trap and connected with the string. As the mouse trap was activated, the dowel rod created pulling force on the string, which unwound, spinning the wheels. Since cds are slick on the edges, we cut balloons on the opening side and the rounded end to get a circle of balloon to put around the cds so that they had extra traction.
what we'd do differently
oNE RATHER LARGE PROBLEM IS THAT AT THE END OF THE MOUSE TRAP'S SNAP, THE CAR STOPPED AND WENT BACKWARDS BECAUSE OF THE STRING WINDING BACK UP THE OTHER WAY. WHAT WE'D DO FOR THIS IS ADD A HOOK ON THE AXLE TO PUT THE STRING ON SO THAT WHEN IT UNWINDS, THE STRING FALLS OFF THE AXLE AND IT CAN GO FREELY UNTIL IT STOPS NATURALLY. WE WOULD ALSO USE A STRONGER TRAP, LIKE A RAT TRAP, IN PLACE OF THE MOUSE TRAP TO ADD EXTRA PULL AND ACCELERATION.
this page made by both brendan and keegan