Mousetrap Car

Some uni work again! Recently, as part of our Mechanics module (Newton's Laws and all that) we were set the task of building a small car powered by a mouse trap to traverse a distance of 5m as fast as possible. Each car was to be built out of 3mm MDF and powered by a spring from a standard mouse trap given to us - everything else was up to us. With CAD software and the laser cutter available, it was decided to take advantage of this, making everything in 3D, assembling it and then laser cutting the wooden components. Little work was actually needed to make the car - cheating I know, but c'est la vie!

Anyway, a 5m track was laid out, with a light sensor at each end, these were connected to a computer and were used for measuring the time taken to traverse the track. A computer program was set up to calculate the minimum time a car should take to run the 5m based on the weight of each car and the engine stored in a control spring...this showed quite a considerable fluctuation in the spring constant of the supposedly identical springs!

Anyway, after this, using various bits of data from the test, and other assumptions made, a set of calculations had to be done to calculate velocities, accelerations and times for the movement of the car. I did these calculations using Excel, with which you are able to produce a rather snazzy spreadsheet where changing one piece of data such as the weight of the car, alters everything!

By the way, after hating Excel for the last 18 years of my life, I have discovered the joy of these snazzy spreadsheets and have introduced The Carpenter to them, who now uses them for calculating information for organ building.

The Engineer.