A winning pinewood derby car through continous improvement: Part 3

Wheels: Take the burrs off the tire surface from the stamping process...we used a 1500 grit sandpaper to smooth the wheels as much as possible. Be very careful or you can create damage to the wheels. We tested the smoothness with the 'close eye-touch finger-spin wheel' test to feel any bumps or leftover irregularities on the surface as we sanded it to measure our progress. Also, we had an additional regulation pinewood derby kit and we picked out the best looking and straightest wheels. Not all pinewood parts are created equal.

Next, we waxed the wheel surfaces with car wax several times for a smooth uniform surfaces. I guess my son did it at least 10 times to build up a nice coat of smooth wax. It was smooth and good looking to boot. We used Johnson Car wax that I had for my car. We even tried waxing the inside the wheel where the axle goes...apparently, it didn't hurt. Lastly, test your wheels and axle out and true them up as best you can. I used a small level and checked to see if everything was trued up and straight with the wheels on. Also, leave a space the width of the pinewood cardboard stock thickness between the wheel and the car body. Friction against the body is bad and will slow performance.

Axles: There is a ton of information about the axle prep on the net-read it and follow it. It's better explained with pictures so do your homework. Here's my two cents-have your son polish, polish, and polish some more til he is sick of it. Then it will be ready. Here's my order of abrasives (that I had around my workshop) for axle polishing :

40 grit sandpaper
60 grit sandpaper
100 grit sandpaper
140 grit sandpaper
500 grit sandpaper
1500 grit sandpaper
00 steel wool
000 steel wool
0000 steel wool

By the time you are done, those axles should be shiny and bright. Be sure to do the same on the underside of the nail head too-it has burrs there that will slow down your car. We used a high speed Dremel like tool for the polishing which improved the process over the 3/8" variable speed drill I used in previous years.

For the axle lubricant, it's graphite all the way. I tried the white teflon stuff for several years and graphite made his car go fast. Another tip: Buy your graphite a month in advance-the day of the derby, the store I went to get it at was sold out...fortunately, a kind soul at the derby let me have some. I believe that the greatest improvement for me was to apply the graphite just before the car was weight certified and impounded until race time. We waited until the last possible moment before "graphiting up" the wheels and attaching the axles in a just in time fashion to improve lubricant retention. Several of the other cars had been finished a few days before and it was very difficult to add more lubricant because the axles were glued on or the car was impounded and moved and jostled around in the competition setup. In our "flow", we planned to have the car completely assembled and ready just minutes before the tournament started and it seems that helped as well. One piece flow is a lean concept...so google it.

Paint - Our cars was painted and sat in front of a fan for 3.5 days before the race. The local derby master had told past participants that vehicle paint should be dry at least 24-48 hours before the race to reduce friction. Fresh paint reduces speed-remember that one! There are some really fancy paint jobs and cool looking cars...but if not planned for, it can hurt the speed at racing time.


The results? My son entered his call in a field of 32 competitors and he finished first! Even racing against the adults, there was only one adult car that beat his by a whisker. My older son's best showing was 7th and he was on hand to watch his younger sibling win it all. As for me, we tried several kaizens that seems to work but the greatest joy was watching my boy beam with pride knowing that he had contributed a large part to the win. Victory is sweet.

What have you improved today?

Kaizeneer

A winning pinewood derby car through continous improvement: Part 2

Ok, here is the brain dump of what my son and I did to get a winning pinewood derby car:

First steps:

1. Get the car kit a month of two before the derby. Start working on the car early to give your son and yourself time to learn and overcome production obstacles. Beginning the work on the car a few days before the race will cause stress and frustration and lead to a poor outcome.
2. Create a work area for the car kit with all the tools so you and your son can work on the car and have everything in one place.
3. Have your son organize the tools and layout of the work area-he will take more ownership in the car and the process.
4. If you can, buy a second kit and pick the best wheels and nail axles out of the two kits.
5. Some choose to buy the books about how to make a winning car. My advice is to check out the library and see what it has on the pinewood derby. Also, networking with other dads will give you 90% of the knowledge you need for a great car.

Car Design

1. Have your son draw designs for the car on paper first 1 to 2 months before the competition. This will engage his mind and create excitement about the process of creating the car.
2. Look at pictures on the Internet to get ideas of designs. Really cool stuff out there.
3. Make it as close as possible to your son's design-this will create more ownership from the boy.

Tools I recommend for this project to speed the production process:

1. Hammer
2. Screwdrivers
3. Variable speed drill
4. High speed drill tool(Dremel)
5. Wood chisels
6. Pliers
7. Jigsaw or ban saw
8. Belt sander

Car body

1. I believe the more aerodynamic the better. He chose a smooth curved shape this year and got good results. However, I do not believe that the greatest speed return will be in this area so don't go crazy with it.
2. Cut the car body with a ban saw or jigsaw.
3. Teach your son workshop safety tips as you go.
4. Sand the body down with a power sander or belt sander.
5. Make it an inter generation project and include grandpa if possible!
6. Sand the body nice and smooth to prepare for painting.
7. Start with a coarse grit and then use finer and finer grit sandpaper for final preparation.
8. Pencil on the bottom of the car "F" for front and "R" for rear - this applies to some designs that are hard to tell front from rear.
9. Do a "axle" test and see if the axles are level by placing the nails in the body axle slots and checking them with a level.

We would travel to my dad's workshop and do all this work. I imagine that we spent about 1-2 hours out in the shop teaching, cutting, sanding, truing, and cleaning up the shop. My goal was that both my sons remember working with Grandpa and Dad on their cars.

Next post will cover things to do for the wheels and axles.

What have you improved today?

Dan Lafever, Kaizeneer