Pinewood Derby Stories and Photos from Maximum Velocity
Lubrication - Slicker is Better
Everyone would agree that lubrication is one of the keys to creating a competitive pinewood derby car. But once the discussion moves into types of lubricants, lubricating methods, etc., agreement begins to vanish. Why? Because there is no one perfect lubricant or one sure-fire way to lubricate.
So, the following information is based on my experience and preference, and I will attempt to explain the reason behind each step. Afterward, the decision is yours as to what to do with the information.
Types of Lubricants
Michael Lastufka discussed the physical nature and properties of the top lubricants in a previous article (Volume 1, Issue 7 - The Elusive Best). But in summary, there are two basic types of lubricants: dry and liquid. This article will focus on the dry category, which contains three primary choices: Teflon, graphite, and graphite-molybdenum. In experimenting with these materials, my observation is that graphite is the superior choice. However, the information in this article will apply to any dry lubricant. For simplicity, I will use the word 'lube' from here forward. To me 'lube' refers to graphite; to you 'lube' can refer to your favorite (or required) dry lubricant.
Before getting into the nitty-gritty of lubricating I would like to offer a few precautions:
Safety - The use of dry lubes can result in a considerable number of particles floating in the air. So when lubricating with a dry lube, wear a particle mask.
Cleanliness - Dry lubes, especially graphite products, can be quite messy. First, apply the graphite outside, or in a garage or workshop. Next, always put some old newspaper on the work surface while lubricating. When done, roll up the newspaper and throw it away.
Axles and Wheel Hubs
Much of the friction that affects the pinewood derby car occurs between the axle and wheel bore. So when lubricating, spend extra time focusing on this key area. Listed below is a procedure for thoroughly lubricating this area.
1. Insert a wheel onto an axle. 2. Hold the axle with the wheel hanging towards the ground. 3. Deposit some lube into the gap between the axle and wheel hub. 4. Tap the wheel gently to help move the lube down into the wheel hub. 5. With one hand, firmly grasp the axle and hold the axle horizontal to the ground. 6. With the other hand, spin the tire firmly, but not so much as to drop the wheel/axle. 7. Repeat step 6, nine more times.
After performing this procedure the first time, keep the wheel/axle pairs together as a unit.
I recommend following the above procedure three to five times before considering this step complete. As a measurement of completeness, if you are using a graphite lube, by the end of this procedure the spin time of a wheel should be twenty seconds or more.
Inner and Outer Sides of the Wheel Hubs
The inner side of the wheel hub will contact the side of the car, while the outer side of the wheel hub will contact the axle head. The previous step should have lubricated these areas. But to be sure, dip your index finger into the lube and rub it onto the inner and outer sides of the wheel hub.
Inner or Outer Edge of the Wheels
As the car is rolling down the track it will bump the guide rail one or more times. So the inner or outer edge of the wheel (inner if the car will straddle a guide rail - outer if the car will be guided by two outside rails) should be lubricated. To lubricate the inner or outer edge of the wheel, dip your index finger in the lube, and rub the graphite onto the tire edge. I recommend performing this step three times.
This is a bit controversial. Clearly, the tire tread should be as slick as possible since traction means friction. Some use auto polish or a similar product on the wheels to make the tire tread as slick as possible. However, we have had good success rubbing some lube on the tire tread.
The inner side of the wheel hub will contact the side of the car. So, dip your index finger into the lube and rub it on the side of the car where the hub will contact the body.
Before taking the car inside, brush off (or blow off) the excess lube. Loose lube does not help the car, but it does make a mess of the track, staging area, carpet, etc.
Thorough lubrication is vital to the performance of a pinewood derby car. So take the time to follow these steps. Don't be like the folks that came to our race a few years back without using any lubricant. The child watched sadly as the car stopped short of the finish line.