Posted On: 2009-01-02
Cub Scouts will find the Space Derby exciting. They blast off with models of miniature "rockets" propeller-driven and powered by three rubber bands that travel along a heavy monofilament fishing line. Join in the fun as the countdown begins for the space race of the century.
1. To stage the race, boys wind up their rocket's motor (rubber band), then hook the rockets over the guidelines, centering the rockets between the vertical dowels and locking the propellers behind the horizontal dowels on the starting gate. Start the countdown and fire at 'zero' by lifting the rear of the starting gate frame which releases the rockets.
2. Run the race in heats, up to four contestants at a time. Boys work hard on their rockets, so each boy gets to try at least twice instead of eliminating him from competition after the first race. For example, in a 6-boy den, try heats of three boys each. The winner of each heat goes into the den finals. Then race the other four again with the winner competing with the other heat winners for the den championship and entry into pack finals.
3. Recruit dads as your flight operations team - two as starters with green flags, two as judges with checkered flags, and two as gate-keepers to line up the boys. Use other adults as inspectors, scorekeeper, etc.
4. Experienced rocket racers warm up their space ships by gradually winding the rubber band motors to full capacity. Try 50 turns first, then 100, 200 and so on. Release the propeller between each winding. Try some backyard runs on a length of monofilament line before competition.
5. Soak rubber bands in castor oil several days before the space derby. This prolongs the band's life and power and will help eliminate breaking during competition. Leaders should have extra rubber bands and props handy for emergencies. Remember that it takes three rubber bands to fly each ship properly.
6. To save time, whenever a ship gives any trouble, pull it off the line and run it with the last heat. Allow boys to wind propellers before coming to the starting gate.
A small hand drill is excellent for winding the rubber bands. It also helps speed up the event. Check the ratio of the drill by making one revolution of the crank handle and count the number of times the chuck turns. Most drills average a 1-4 ratio. It would take 40 turns of the crank to give you 160 winds on the rubber band motor. It is advisable to have one person hold the rocket and propeller while the other stretches the bands, about 1 1/15th" beyond the rocket tail, and turns the rubber bands, gradually shortening the distance between him and the rocket.
A handmade fitting of coat hanger wire makes winding easier. The wire for this winder accessory is not included in the kit, but can be easily made from scraps around the home.