Wednesday, April 6, 2011

Pinewood Derby Hershey Bar and Bus

Here are the pinewood derby cars that Zac and I made this year.

His is the Hershey Bar and mine is the Webelos School Bus.  He saw a Hershey bar car in an issue of Boy's Life magazine last year and he has been planning on building one all year.  The car is super easy to build because there is no paint, just some aluminum foil and a Hershey's wrapper.  Spray adhesive was used to secure the coverings and about 3 oz of weight had to be added to the car to make it 5 oz.
The Hershey Bar Car turned out to be really fast and won the Pinewood Derby.  I think that having all of the weight in the rear and having a low center of gravity helped make this happen.  My personal opinion is that the axles and wheels are most important part of getting the best speed possible.  Well polished and true axles with good graphite as a lubricant is a must.  Our pack does not allow increasing the wheel base but I am told this helps and running on three wheels helps reduce rolling resistance.

My car is the same as I usually make each time I am leading Webelos because it is the last year that the boys will be racing pinewood derby cars and I have the bus as a keepsake to remember them by.  The photos are from their yearbook and all of the details on the bus are printed on decal paper.  The bus is the opposite of the Hershey bar because it needs to be hollow to make it weigh 5 oz.


  1. These are GREAT! I love the bus idea with the kids pics. And Zach did a great job on his Hershey Bar---everyones favorite!! Judi

  2. I did a similar bus but I called my The Magic Scout Bus! The boys loved it since they got to see themselves on the bus!

  3. what kind of information do u have on this hershey bar gravity car

  4. The only information I have is to cut the standard pinewood derby car blank down in thickness and wrap a Hershey wrapper with aluminum foil around the blank. You'll end up adding weight to get up to 5 oz and I think we added the weight to the back of the car.

  5. My son wants to make a Hershey's Car rally bad. How thick did you cut the blank and what kind of weights did you use?

    Thank you so much! I love the bus!!!

  6. I went looking for the car just now and I cannot find it to measure it for you. It has been a few years since he made the car...

    If I had to guess, I'd say it was about 5/16" thick. The weight is lead added towards the rear of the car. We drilled holes and either melted lead and poured it into the holes or added lead shot into the holes (the shot cannot move since that would be a rule violation). When you drill the holes you loose weight but the lead is so much more dense than the pine wood that you end up adding weight. It takes a fair amount of trial and error to get it right but everything is covered by the wrapper. The final small adjustments are made with foil tape but don't forget the weight of the wrapper and aluminum foil.

    Best wishes!

    1. Looking at the math, if the car ended up at 3 oz the width must be about 3/5 of a pinewood derby blank (whatever that is). I'm sure he made it so the wrapper fits around and it "looks" about right. The thicker you make it, the less weight but the thinner you make it, the faster it will be.

  7. I have one more question. Did you spray anything on the Hershey wrapper to cut down on friction on the wheels?

    Please let me know.


  8. No, I don't think that we did anything to the wrapper but we might have put a dot of paste wax there and buff. I think it is important to make sure that the wheels are pulled out away from the body of the car when it is put on the track to prevent friction from rubbing against the body of the car.