Pinewood Derby Clinic

Dennis Wang
Cubmaster – Pack 199
Pinewood Derby Chair
Pathfinder District
Introduction & Welcome
Dennis Wang
Cubmaster – Pack 199
Pinewood Derby Chair
Pathfinder District
Pinewood Derby Enthusiast
Pinewood Derby Cars
2013 Wolf Scout - Batmobile
Pinewood Derby Cars
2013 Sibling – PVZ Lego Race Car
Pinewood Derby Cars
2014 Bear Scout - Enderman
Pinewood Derby Cars
2014 Tiger Scout - Steve
What are we going to do today?
We
are not building cars today
Good Sportsmanship
Go over strategies for building a fast
car
Review of tools needed to build a car
Going over basic building techniques
The Down and Derby Syndrome
Who should build the car?
Scout
Dad
Both
Sportmanship
Cub Scout Motto?
Know the rules of your race
○ Pack and District races can and should have
rules
○ Follow the rules
In every race, there will be one winner
and then everyone else. At the end of it
all, there will be one winner and then the
rest of the pack.
Sportsmanship
It’s not about winning
It’s about having building something as a team:
Akela and Scout.
It’s about watching that car race down the track
It’s about learning something new:
○ Physics
○ Craftsmanship
○ Using tools
○ Good sportsmanship
Remember the Cub Scout Motto and the core
value of Positive Attitude
Pinewood Derby
It’s about having fun!
Pinewood Derby Clinic
Physics Clinic
Pinewood Derby is really all about
physics
Energy
Kinetic Energy (Motion)
Potential Energy (Stored Energy)
○ Batteries are stored energy
○ Lifting a weight creates stored energy
Physics Clinic
Energy
Center of Mass/Balance Point
Where do you want the Center of Mass of
the car to be: front or back?
Physics Clinic
Conservation of Energy
Ideally, all the potential energy is converted into
Kinetic Energy
Ideal Conservation of Energy
10
8
6
4
2
0
Potential Energy
Kinetic Energy
Physics Clinic
Friction
What is friction?
Friction Experiment:
Kinetic Energy is motion
Pretend to rub your hands together
Now rub them together really fast
How do your hands feel?
What forms of energy did you convert
motion into?
Physics Clinic
In reality, some of the potential energy is
converted into other forms of energy
Actual Conservation of Energy
10
8
6
4
2
0
Potential Energy
Kinetic Energy
Friction (Heat) Rotational Energy
Sound
Physics Clinc
Physics
and the Pinewood Derby by
Scott Acton
Conducted many experiments and
documented the impact they have on speed
Published a DVD on his experiments
Physics Clinic
#
Parameter
Car Length Advantage
1
Center of mass location
4.6 (36%)
2
Lightweight wheels
2.1 (16%)
3
Aerodynamic
1.4 (11%)
4
Polished nails
1.3 (10%)
5
Lift one wheel
1.1 (9%)
6
Graphite
0.9 (7%)
7
Other (long wheel base, car shape,
wheel gap, etc.)
1.4 (11%)
Tools
Safety First
Hand Tools
Power Tools
Pinewood Derby Specific Tools
Tools: Safety
Always supervise Scout while using
tools
Safety Goggles
Hearing protection
Tools: Hand Tools
Saw
Coping saw
Cross cut saw
Hammer
Pliers
Clamps
File
Sandpaper
Tools: Power
Saw
Band saw
Scroll saw
Drill
Sander
Belt
Rotary
Rotary Tool
Dremel
Tools: Speciality
Weights
Lead
Tungston
Other alternatives
Digital Scale with accuracy in the hundredths place
Graphite lubricant
Axel Pliers
Axel Guide
Axel Press
Hub Shaver
Wheel Mandrel
Axel Polishing Kit
Building The Car
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Insert Axels into pinewood block
Polish Axels (Parameter #4: Polish Nails)
Come up with a design*
Cut out and shape the car
Paint the car
Weigh all parts to determine how much weight
is needed to get you up to 5.0 oz.
Install the wheels
Weigh the car again to make sure it is at 5.0 oz
Align the car *
You car is now ready to race
Building The Car
Step 3: Come up with a design
Know your rules
○ Max weight is 5.0 oz
○ Dimensions (max 7” x 2 ¾” x 4 ½” )
○ Certain shapes may not be allowed
Which end of the block is the front of the car vs the back
of the car (Parameter #1: Center of Mass Location)
Determine where weights will be added (Parameter #1:
Center of Mass Location)
Shape (Parameter #1: Center of Mass Location and
Parameter #3: Aerodynamic)
Draw the design on the template
Cut out the template and attach it to the pinewood
block
Building The Car
Step
9: Align the car
Not listed as a parameter, but it is very
important
Straight
Rail rider
Race Day
Be prepared to adjust the weight of your
car when you check in. Your scale is
probably not exactly the same as the
official one.
Have extra weights: weighted putty is good
to have
Bring a drill so you can quickly remove some
weight from parts of the car
○ Just drill out a few holes from the bottom
References
You can buy books from the Scout Store
All tools listed are available in the Scout
Store
References on the second to last page
of the packet
Template is available on the last page of
the packet
Questions?
cubmaster@pack199.nwsc.org