[Broken External Image]:
Here's my son with his 2010 car. He only came in second once.
Flipped car over, cut grooves off and drilled HOLES for axle nails. Chucked each axle nail in the drill press and cut the flashing off, then sandpaper, then 000 Steel Wool, then polishing with jewelers rouge.
Found a mandrel for the wheels, spun each one up and sanded off the sharp edges, rounded the face so it only touches in the center, then 000 steel wool to smooth. Graphite goes inside and out on the wheels.
Measured a penny, then drilled penny-sized holes in the underside of the car. Cut a piece of perforated metal strap to cover the holes with a screw at each end. It allows you to EXACTLY match the scale at the meet at exactly 5.0 ozs. Add or subtract pennies as needed. Take a roll with you. Weight is absolutely critical!
Put as much weight as possible near the rear of the car, but in front of the rear axle. Rearward weight bias puts the weight as high as possible to maximize potential energy. Inside the wheels improves stability.
Make sure no paint gets on the spot where the wheels touch the car. Graphite that spot. Press the wheels on with a drill press to as close as possible while still allowing a little play for free running.
P.S. Let the kid do some work, too! Josh now knows how to use the drill press to spin axles and wheels. He used the dremel to work on the final shape. He'll do more of the work himself next year, with supervision.
