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Pinewood Derby Times
Volume 8, Issue 2
October 15, 2008

In this Edition:

- Editor's Notes

- Feature Article - Graphite on the Tread

- Humor

- Product Showcase

- Car Showcase

- Q&A


Editor's Notes

Reader Feedback

From Tim Hellaby - Myrtle Beach, South Carolina:
Is a car running on one wheel faster then a car using all four?



This photo wasn't staged - I just happened to get a chance shot. I was taking a photos of my sons car (the blue one leading in lane four) when the car in lane three just happened to jump up as it neared the finish line.

From Alan Williamson, regarding the article, "A Winning Philosophy" in Volume 8, Issue 1 - October 1, 2008:
I have basically eliminated the win at all cost theory from our pinewood derby. The first thing I recommend is that you have a derby workshop, and tell all the parents about the tricks -- the ins and the outs. Talk to the youth about winning and fair play. Create an atmosphere where the parents and the children are involved in creating the car. Even the worst defeat is a win.

One parent came up to me and said, "Well, looks like your boy's car suffered in this race." I asked why he said that. He replied, "He only came in third overall." I chuckled and told him something that I think really stung him, "Well this year I let him decide on how to do it; I only cut it out. He painted it, and then took what I had taught him the year before to finish it out. He thought he did his best, and that was fine with me. Furthermore it allowed me to have a hand in every car out there. How could I have lost?" I asked him if he saw any boy with tears in their eyes? He replied, "No." I then replied, "But I heard a lot of them saying they would win next year."

The next year, this parent was the first in line to help chair the derby and even bought a portable band saw to help with the cars.

It is amazing to me how my first pinewood derby race shaped my thoughts of winning and losing. Yes, seeing that car stop halfway down the track and losing hurt. But it made me more and more determined each time I have built a car. The determination for me now is to make sure each boy has a positive experience no matter if they win or lose.

From the Editor: In my experience also, the attitude conveyed by the race officials has a significant impact on the attitude of the participants.
Product Updates
With the uncertainty in the economy, most Americans are watching their spending more closely. To help get the most for your dollar we are offering two car kit bundles at over 25% off retail. These kits consist of a pre-cut car kit, weight, official BSA Speed Wheels, BSA Speed Axles, and Max-V-Lube Graphite. You can find these bundles Here.

In addition, we have placed some of our Official BSA Speed Wheels on Inventory Clearance. You can find these wheels Here.

Finally, the Official Awana 1.0 Gram Speed Wheels are now available Here.


Do You Have a Pinewood Derby Memory to Share?

We are out of memories to share with our readers, but I am sure that many of you have a story to share. So, please type up your humorous, unusual, sad, or heart-warming pinewood derby tale and send it to info@maximum-velocity.com

If your memory is used, you will receive a $10 coupon in May of 2009. Don't worry about literary polish. We will edit as needed. Also, please read our Submission Policy

Can We Help?
If we can help you in any way with your pinewood derby project, or if you have any feedback regarding this newsletter, please contact us at: info@maximum-velocity.com


Feature Article

Graphite on the Tread

Do you put graphite on the tread surface of your wheels? Come on, you can admit it. I started rubbing graphite onto the tread surface about eight years ago. It seemed like a good thing to do, and it made the tires look nice and shiny. But honestly, during this time I didn't know whether it did anything to improve the speed of the car.

So I decided to test whether applying graphite to the tread surface has any effect on speed. While doing this, I also tested the benefit of applying graphite to the inside edge of the wheel (the part of the wheel that touches the center guide rail).

Experiment Equipment

The experiment used the following equipment:

Experiment Set Up

Before mounting on the car, the wheels were thoroughly lubricated with Max-V-Lube4. To prevent the graphite from getting onto the tread surface or inside edge, the wheels were wrapped in paper (Figure 1).


Figure 1 - Wheel Wrapped in Paper

After lubrication, the paper was removed and the wheels were mounted on the car. The car was then aligned, and given a few break-in runs.

Experiment Procedure

  1. The car was run six times, the high and low runs were removed, and the heats were averaged.


  2. Graphite was applied to the tread surface of each wheel. This was done without removing the wheels. To prevent graphite from getting on the inside edge of the wheel, a piece of cardboard was pressed against the inside edge of the wheel.


  3. Again, six heats were run, the high and low runs were removed, and the heats were averaged.


  4. Without removing the wheels, graphite was applied to the inside edge of each wheel.


  5. A final set of six heats were run, the high and low runs were removed, and the heats were averaged.
Experiment Results

The following chart shows the results of the test. As you can see there was a slight improvement in performance when graphite was added to the tread surface, and then again when it was applied to the inner edge.

Note that the amount of overall improvement is only four thousandths of a second. However, the heat times were very consistent; the standard deviation (amount of deviation of the heat times from the average) is quite small (ranges from 0.0005 to 0.0017). Thus, the improvement, albeit small, cannot be completely attributed to statistical noise.


Figure 2 - Experimental Results

Conclusions

Although the small improvement could be important in a tight race, lubricating the tread surface and inside edge is an extremely small factor in overall performance. If allowed in your race, I would certainly do it, but you would not suffer a significant performance penalty if you choose to not lubricate the tread.

Another factor to consider is that the anodized aluminum track on which the experiment was run is extremely smooth. It is possible that if the experiment was run on a rougher track, there could be a larger performance improvement. However, rougher tracks do not generally provide consistent heat times. So the standard deviation of the heats would likely be much higher, and any improvement could be buried in the statistical noise.

1
Wedge Kit: Part 5622

2Pro-Stock Speed Wheels: Part 4080

3Speed Axles: Part 4095

4Max-V-Lube: Part 5104




Humor

Intelligence Quiz

  1. How do you put a giraffe into a refrigerator?

    The correct answer is: Open the refrigerator, put in the giraffe, and close the door. This question tests whether you tend to do simple things in an overly complicated way.


  2. How do you put an elephant into a refrigerator?

    Did you say, "Open the refrigerator, put in the elephant, and close the refrigerator?"

    Wrong Answer

    Correct Answer: Open the refrigerator, take out the giraffe, put in the elephant and close the door. This tests your ability to think through the repercussions of your previous actions.


  3. The Lion King is hosting an animal conference. All of the animals attend except one. Which animal does not attend?

    Correct Answer: The Elephant. The elephant is in the refrigerator. You just put him in there. This tests your memory. Okay, even if you did not answer the first three questions correctly, you still have one more chance to show your true abilities.


  4. There is a river you must cross but it is used by crocodiles, and you do not have a boat. How do you manage it?

    Correct Answer: You jump into the river and swim across. Have you not been listening? All the crocodiles are attending the animal conference. This tests whether you learn quickly from your mistakes.
According to Pachyderm Consulting Worldwide, around 90 percent of the professionals they tested got all questions wrong, but many preschoolers got several correct answers. Pachyderm Consulting says this conclusively disproves the theory that most professionals have the brains of a four-year-old.



Product Showcase

    Steel Weight    

Steel Weights are an environmentally friendly, inexpensive weight for pine derby cars. They are more dense (7.7 g/cm3) and less expensive than zinc weights (7.0 g/cm3).

Steel Weights measure 3/16 x 3/16 x 1-1/4 inches, and weigh 0.19 ounces each. They are generally applied to pine derby cars by creating one or more pockets on the bottom of the car to accomodate the weight. The weights are then glued in place with epoxy. Steel Weights are very hard, so do not plan to drill or cut them. Instead, use an alternate method to make fine adjustments such as tungsten putty, tungsten, beads, screws, etc.

Steel Weight - $1.00 off

Until October 28, 2008, you can purchase a set of Steel Weight for $1.00 off the regular price. To take advantage of this limited time offer,
Click Here.



Car Showcase



Ski Racer: Tom Bybee


My 8-year-old daughter took skiing lessons this year and was wildly enthusiastic about the sport. Her first car design was a natural expression of her new-found passion. She placed second in the siblings race at our Pack.

NASCAR COT: Caterpillar Toyota: Brent Whitlow


My father and I take pride in creating full-bodied NASCAR style pinewood derby cars. Since the COT (Car of Tomorrow) made its debut last year in the Nextel Cup, we have been trying to create a pinewood derby version. This year we were able to debut our first ever COT at our local SAPCAR pinewood derby racing event.

Pink Ghost: Brian & Brianna Fenech


This car is my daughter's submission from her April 2008 Awana Grand Prix race with Adamsville Baptist Church. The paint is a bright pink with ghost Lemans stripes. The car features an extended wheelbase wedge design, offset front wheels, and raised right front wheel. We used flat black under the nose to ensure instant timing light trigger. All the tungsten weight is located near the rear axle, precisely at 5.0 ounces. The wheels are race-ready, graphite-coated slicks. The axles were smoothed and grooved to reduce friction and utilized Krytox oil rather than graphite lube. The car raced a total of eight class heats. It sped to 1st Place - Top Speed in Class, then Top Speed Overall to beat all competition, including parents. The car also garnered 2nd place in class for design. We're looking forward to starting our 2009 Awana Grand Prix racer. By the way, Brianna was also the reining 2007 Top Speed Overall, (See Car Showcase in
Volume 7 - Issue 9

Share your car with our readers!

Do you have a car you would like to 'show off' to our readers? If so, send us a photo of your car along with a brief description of any special features. Also, please include your full name. If selected, we will include the photo and description in this newsletter.Please e-mail photos to:
info@maximum-velocity.com.

Photos must be sent by e-mail in JPG format (minimum size of 640x480, maximum size of 1280 x 960). Please shoot photos from the front left of the car, similar to the orientation of this car:


Send only one photo per car, unless an additional photo is needed to adequately show a feature. Also, only one car per subscriber per year please. Thanks!




Q&A

How do Pinecar wheels compare performance wise to the BSA wheels if preparation is the same for each?

I have not directly compared them, but from comments of others, BSA wheels tend to be a little faster. The PineCar wheels have most of the weight on the outer circumference, which increases wheel inertia, and slows down the start.

My son has a question that I can't answer with certainty. He said that when you drop two objects with different weights from a same height they will arrive to the ground at exactly the same time, if they have the same wind resistance. So, why is the heavier pinewood car usually faster than a lighter car, given that the amount of weight is the only difference between the two cars? I think it has something to do with the friction on the wheels and axles, but do you have some scientific explanation for this? Would all pinewood derby cars have exactly the same speed and arrive at the same time at the finish line if there is absolutely no friction and no wind resistance?

You are correct that two objects, regardless of mass, dropped from the same height will hit the ground at the same time if they are in the presence of a vacuum (no air). You are also correct that if there were no friction or wind resistance, then all cars would arrive at the finish line at the same time regardless of the shape or weight (or at least they would be close - wheel alignment would affect the result).

But in reality, friction does exist. When the car reaches the flat part of the track, it will have achieved its maximum speed. It will then begin to slow down. The rate at which it slows down is dependent on the amount of friction, and the mass of the object. Momentum (which is mass times velocity) is the force that helps the car overcome friction and keep rolling. So the heavier the car, the greater the momentum, and thus, the better performance. Of course, reducing the amount of friction through wheel/axle preparation and lubrication are vital as well.

Some older tracks do not have a flat section - they just have a continuous slope from start to finish. On these tracks, mass is less important than on a standard track, however, it is still needed to overcome all of the frictional forces.

Do You Have Questions that Need Answers?
Do you have a pinewood derby-related question? If so, send your question to:
info@maximum-velocity.com. We answer all questions by e-mail, but not every question will appear in the Q&A section of the newsletter.



Back Issues

Are you a new subscriber, or have you missed some of the previous newsletters? Don't miss out!

We have just added an index of all newsletter articles since the first edition in October of 2001. We hope this helps you find information more quickly. To view the index Click Here

All of the issues for Volumes 5 through 8 are posted on our web site:

Volume 8

  1. Volume 8, Issue 1

  2. Volume 8, Issue 2
Volume 7

  1. Volume 7, Issue 1

  2. Volume 7, Issue 2

  3. Volume 7, Issue 3

  4. Volume 7, Issue 4

  5. Volume 7, Issue 5

  6. Volume 7, Issue 6

  7. Volume 7, Issue 7

  8. Volume 7, Issue 8
  9. Volume 7, Issue 9
  10. Volume 7, Issue 10
  11. Volume 7, Issue 11
  12. Volume 7, Issue 12
  13. Volume 7, Issue 13
  14. Volume 7, Issue 14
  15. Volume 7, Issue 15
Volume 6

  1. Volume 6, Issue 1

  2. Volume 6, Issue 2

  3. Volume 6, Issue 3

  4. Volume 6, Issue 4

  5. Volume 6, Issue 5

  6. Volume 6, Issue 6

  7. Volume 6, Issue 7

  8. Volume 6, Issue 8

  9. Volume 6, Issue 9

  10. Volume 6, Issue 10

  11. Volume 6, Issue 11

  12. Volume 6, Issue 12

  13. Volume 6, Issue 13

  14. Volume 6, Issue 14

  15. Volume 6, Issue 15
Volume 5

  1. Volume 5, Issue 1

  2. Volume 5, Issue 2

  3. Volume 5, Issue 3

  4. Volume 5, Issue 4

  5. Volume 5, Issue 5

  6. Volume 5, Issue 6

  7. Volume 5, Issue 7

  8. Volume 5, Issue 8

  9. Volume 5, Issue 9

  10. Volume 5, Issue 10

  11. Volume 5, Issue 11

  12. Volume 5, Issue 12

  13. Volume 5, Issue 13

  14. Volume 5, Issue 14

  15. Volume 5, Issue 15
Volume 4 is available as a PDF file, ready for immediate download.

Volume 3 is available as a PDF file, ready for immediate download.

Volume 2 is available as a PDF file, ready for immediate download.

Volume 1 is available as a PDF file, ready for immediate download.





Newsletter Contributions

We welcome your contributions! If you would like to contribute an article, a web site review, or a speed tip, please send it to: info@maximum-velocity.com.

Please read our submission policy.




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Randy Davis, Editor, Pinewood Derby Times
E-Mail: info@maximum-velocity.com


Copyright ©2008, Randy Davis. All rights reserved. Please do not reprint or place this newsletter on your web site without explicit permission. However, if you like this newsletter we grant permission, and encourage you to e-mail it to a friend.

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