I made the car “Sling Shot” to enter in the 2012 Milwaukee “Nerdy Derby” at Barcamp7 this weekend. A lot of people were talking about adding motors and fancy electronics, but my car is powered by a spring – a 10 foot length of surgical tubing that is stretched to another block of wood that must be clamped down. I added wheels, but they aren’t necessary – they don’t actually even touch the track.
Check out what may end up being the only two runs the car has. Fortunately, JRock captured some video of them. I’d estimate that the car took 0.1 or 0.2 seconds to travel the 40 foot length of the race track, giving an average speed of 300 feet per second (200 mph!). The great part about this “sling shot” design is that the car is accelerated by the surgical tubing spring throughout the first 30 feet of the track – until the surgical tubing is completely unstretched. “Beautiful!”