Pinewood Derby Q&A

My nephew asked me to help with his pinewood derby car.?

My nephew asked me to help him with his pinewood derby car for cub scouts. I know it needs to weigh no more than 5 ounces and should be very air dynamic. Has anyone ever made a amazingly fast car?

Public Comments

1. the aireodynamics come pretty low on the list other than it has to look cool for him. get as close to 5 oz as possible that is probably the mainthing otherwise pend some time on the nails that make the axels and wheels. Use sand paper or a small file to remove all burs. they actualy sell a tool at scout shops to mount the wheels on a drill to spin them. also make sure the axels are straight. the slots already cut in the body are not gauranteed to be square withthe body. I like the extra weight by the back wheels but was actualy diaqualified one year for having a ball bearing thst shifted the weight rom the fron to the back as the track leveled out. just before the race hit all the axels with some dry graphite . My sons took 1st or 2nd every year.
2. there really is no guarantee, the most important thing is to get the axels (the nails that hold the wheels on) very very smooth, use a piece of sandpaper or a dremel tool to smooth them out. be careful of weight. our group let us keep adding peices of duct tape on the day of the race so that they could get it up to weight. my son's last car was cut in a wedge shape and he glued buckshot on the back angle of the car... it was fast but did not win.... like i said, you can never tell. i think for little ones it is more important that they think the car looks cool and they participate. good luck
3. Here's the fastest Pinewood Derby car around.... http://cgi.ebay.com/ULTRA-FAST-PINEWOOD-DERBY-CAR-BUILT-by-PHYSICS-TEACHER_W0QQcmdZViewItemQQcategoryZ2595QQihZ014QQitemZ330197566570QQrdZ1 Copy it. Aerodynamics plays VERY LITTLE factor. Weight helps, but only 1/25 of a second at worst. What really matters is the use of Graphite on the axle (Oil is against the rules). Coat the axle with graphite. Put the wheel on the axle then put the axle into a slow speed drill. Work the drill with graphite for about a minute. Put the wheel/axle assembly onto the car properly. Not too close, but definitely not to far from the car body. Make it almost touch. Do not super-glue the axles yet!!! Now, test the car on a flat surface. Make sure that it does not veer or stray away. Do several test, including a sloped ramp. Each time you test the car, you can tweak the axles. Usually they will straighten themselves with a few runs. Now carefully glue the axles in place. P.S. Polish any burrs or snags off, from the plastic wheels. Good Luck