How to Polish Your Pinewood Derby Car’s Axles and Wheels
The quality of your Pinewood Derby car’s axles and wheels may be the most important factor in building a fast car. Here’s how to choose and polish your car’s axles and wheels.
Polishing Pinewood Derby Axles
1. Start with a set of raw axles.
2. Can you tell the difference between the axles in the top row and the ones on the bottom? The ones on the bottom aren’t straight and will slow your car.
3. To tell which are straight and which aren’t, mark each axle with a marker about 1/2 inch from the pointed end.
4. Have an adult clamp a power drill into a vise, a device that will hold it perfectly still.
5. Have an adult help you insert each axle into the drill at the location you marked in Step 3. Have the adult turn on the drill.
6. Bent axles will wobble as they turn in the drill. Straight axles will hardly wobble at all. Pick the ones that wobble least.
7. Once you’ve selected the four straightest axles, use a file or fine-grit sandpaper to remove small burrs and mold marks that can cause friction and slow a car. These imperfections should be removed from both the axles and the wheels. Watch this video to learn one way to do this.
8. Use polishing compound from the auto supply store to polish the wheels and axles. One easy way to do this is to clamp the axles back in the drill and let the drill spin the axle while you polish it.
9. When you install the axles and wheels, make sure they are aligned perfectly straight. You can test the alignment of your axles by pushing your car across a smooth floor or table. It should roll in a straight line.
10. Don’t forget to add graphite or another dry lubricant to your wheels and axles.
My son had a good first year derby experience finishing in second place. The next year I asked him to make a sketch of his design for the next competition. What he drew was an exact copy of the car that beat him the first year right down to the lightning bolt.
Tiger Cub dads get way too into it. By the time they are Webelos the parents let the kid do it all. I don’t know how I feel about many modifications to the car. It gets way too competitive sometimes.
One of my sons was an engineering student at Duke. They used the BSA Pinewood derby cars as a project for the students to build over Thanksgiving break for one of the labs. The techniques we used in Cub Scouts proved a winning combination at Duke.
I have two kids. The older one eight did all the cutting and painting himself and needed some help to mount the wheels straight.
The younger one age 4, couldn’t do the cutting. Her contribution was the paint job (bright pink). This car came in 2nd in the adults and sibling category.
We did a test of just the block of wood out of the box (no cutting or painting) with just the wheels and nails out of the box. It beat out all but a few cars.
Lesson here – it is absolutely possible to make your car faster if you polish up the axles, distribute weight properly etc…but if you dont do it REALLY well, you’ll just make things worse.
How about if Dad’s just keep their hands off the cars once the cutting is done? Let the kids build the cars as they come in the kit.
It’s supposed to be a joint project for bonding and learning time. Very little in cub scouts is hands-off by the parents.
Stay in your lane.
The car is a cooperative effort between scout and parent.
This is always a sticky subject. My son really looked forward to spending time together building. He did most of the work himself, but we spent 4-6 weeks at it. Our goal was to make the car he imagined and build relationship. Each pack should clearly define the goal for its members, then ask the adults to behave.
Lol… soo funny, just enjoy the time with your children! My three year old painted his and I had to help him put the wheels on.
How about we require a build journal with pictures to eliminate these “bought on the internet” cars?
I’d use three straight axles and take one bent one. Put the bent one on a front wheel and mark a line on the head from center to edge. Roll down an incline. If car veers to one side, use needle nose and rotate bent axle 45° if it i if it’s worse,rotate in other direction and tweak until straight. Better option then pulling down on a wheel and cracking the wood.
Some dad’s enjoy the quality time with their kids. It is a project that is supposed to be done together. Mu Tiger scout could not do any of this. So we do it together.
How can you fix it
We did this to perfection. My son was winning by such a margin, that two parents placing the cars on the track started cheating and lubricating every one of the other cars before racing them.
Watch a Movie called Down and Derby if you want to see parents out of control.
Graphite needs a few days of spinning to shear correctly, they weren’t doing those builders a whole lot of good 😞
When polishing the axles, only take of the minimum material to make them smooth. Too much removed will result in wobbly wheels too.
Good tips ..
This. My son made this change this year and it was fantastic. We noticed the wheels rattling, so he went real gentle on the polishing and once we got the graphite smoothed out the wheel wobble disappeared and ended up yielding a big trophy and a lot of pride.
Will wobbled wheels slow it down
Getting the car to track straight is big too. If the car pulls it will scrub off speed. So if it pulls left ,pull the left wheel down . If the wood splits use gorilla glue.once it tacks up enough finish the test gently .let it dry .
I tried a 2.5mm angle on my steering wheel up front. Don’t do it.. it jumps the track to the center…. use 1.5mm angle only on fronts.
if you have a bent axle.. or just want to start from straight.. reverse the axle/nail in the axle bending tool up to the head.. then give it a couple of wacks with the hammer, do this at 12:00, 4:00 and 8:00.. by rotating the axle. This should give you a good straight axle to use.. then you can have a more accurate angle in your axle.
In my opinion, properly aligned, highly polished axles is the most important factor in all fast Pinewood Derby vehicles!
These are real helpful tips