Pinewood Derby Car Help

[kd...]

Having had three sons go through the cub scout program we've built our share of pine-wood derby cars. If the nails have a bumpy section next to the head be sure that you smooth it up by chucking the nail in an electric drill and filing the "barbs" off the underside of the nail head and the nail shaft next to the head. You might even find some "better-smoother" nails for the wheel axels. Get the weight as close to the 5 oz as you can without going over. You can do this two ways. 1. Load it a little heavy and then drill it out the night of the race with your electric drill. 2. Drill a couple of empty holes in the bottom and then push plumber's lead wool into the holes with a blunt punch the night of the race. You should do this while checking on the scale they use at the race. Make sure the wheels are perfectly round so they don't "hop" as they spin. The best way to do this is on a lathe but it can be done in an electric drill or drill press. Just mount them on a small bolt and chuck them in the drill and smooth them with a file. Some people file the edges of the wheels so that they have a sharp "V" edge that runs on the track. This reduces friction also. Make sure that the car runs perfectly straight so it isn't crowding one edge all the way down the track. If the car straddles a central guide strip on the track instead of running between two guide strips, be sure that nothing on the car can ever touch that center guide strip. This is especially important where the track bends from the down hill slope to the flat level straight part. I've seen a lot of cars drag their rear bumper right there at the bend. Lube the wheel axels with powdered graphite and shape the car with a low sharp nosed smooth profile. A bullet shape or torpedo shape is great. Give it a real nice smooth paint job and then wax it! That should do it.
[signature]