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Tips & Tricks for a Faster
Pinewood Derby Car
How Fast Can Your Car Go?
Here are some of the best tips for making your car run faster
and straighter. Click on the links to read more about each technique.
Submitted by: J. Maney Jr., Straight Arrow
Northern California/Nevada district
Cut the block into a wedge first and
making your final body shape around the wedge. Aerodynamically,
this makes a faster car.
Submitted by: J. Maney Jr., Straight Arrow
Northern California/Nevada district
Put your tires on a small
lathe and taper them. Ending up with a tire that is V-shaped
instead
of
round. This reduces the area of contact with the track thereby
reducing friction and again greating an aerodynamic tire.
Submitted by: T. Hall, Leader
Southern California district
Using
a brad-point, drill holes the same size as your axle. Drill
your axle holes as far apart as possible, remember your
bottom
clearance.
Make your car as long and as low as possible, experiment with blocks to find
the best combination. Placing your weight one inch ahead of
your rear axle and as low in the car as possible works very well.
Tap your axle hole with a 6/32 tap,
then roll the wheels on the polished axles to rub inside burrs
off.
They hold lubricant better.
Submitted by: D. Black, Leader
Arkansas district
Another place you should
look to reduce friction is on the faces of the wheels themselves.
When the plastic wheels are molded, they frequently have "burrs" where
the manufacturer's mold had seams. These burrs cause your wheels
to roll unevenly and actually make the car "bounce" down
the track. This bouncing action will slow down your car considerably.
You can remove the burrs from the wheels
by sanding, using a Dremel tool or drill.
Take
a full-thread screw small enough to go through the hole in the
wheel and put a lock washer and nut on to clamp the wheel secure
to the screw. Chuck the screw into your drill or Dremel. Use
some type of sanding block with a fine grade sand paper and as
the drill
turns the wheel against the sand paper, your results should be
an even amount of sanding around the entire wheel.
Be very careful here, because a little sanding goes a long way.
If you sand to much off, you can actually cause a "flat spot" on
the wheel. You want your wheels to be a close to perfectly round
as possible so they roll smoothly.
Submitted by: S. Black, Challenger
Minnesota district
When working on your
car, sanding is crucial. You want your car to look good and have
better aerodynamics. Take a course grain
sand paper and get out the big nicks and bits. Then move to a finer
grain and really smooth it up. When finished with that, put a primer
on then sand that away until smooth. This will make it more smooth
and keep the next layer of paint from soaking into the wood. When
you are done with the sanding, you should know that your car is
going to run better. Apply your paint evenly when you're done
and then gloss it if you want for a really neat look.
Submitted by: D. Perich, Leader
Ohio district
As a car goes down the track, it
wanders from side to side and the inside edges of the wheels bump
into the center guide on the track. Both wheels on
one side will bump, then both wheels on the other.
If the width of the front end of the car is sanded
slightly narrower than the back end of the car, then the wheels
on the front will be slightly closer together. When the car goes
down the track, only the front wheels will grind against the center
ridge. The back wheels will never touch it. The reduced number
of contact points will reduce friction and your car will go faster.
Submitted by: C. Wilson,
Leader
South Texas district
Keep in mind that your car will
act differently depending on how heavy it is. Weight influences
friction and inertia. As weight increases so does friction. Heavy
cars can take longer to "get started" due
to inertia. But if your track has a long, flat run at the end,
heavy cars will maintain their speed longer.
Make several timed test
runs at various weights and pick the one that works best for
you. If you race on different
types of track (all sloped vs. sloped with a flat run-out) you
may need to "re-tune" your weight for best performance.
If you have the opportunity to put your
car through some "test runs" on the track, try this little
tip. Sometimes, a car rolls faster backwards than
it does forwards! This tip became obvious when at a derby,
a slower car was accidentally placed on the track backwards, and
it won!
If you have a chance to test-run your car, time
it both forwards and backwards. You may find it runs faster backwards!
Submitted by: P. Starns, Pioneer
Alabama district
Sometimes all you need is paint
to give your car a psychological edge. Some people believe
that if a car
is
red and it is involved in a tied race, judges go for the red
ones.
Note: If your outpost uses electronic
timing devices, this won't give you an edge, but you never know
with human judges...
Submitted by: S. Black, Trailblazer
Minnesota district
Another way to get
your car to go faster is make it sleeker and thinner. One technique
is to cut your car to about 3\4 of an inch in height. Then make
the car thin enough to
drill into
and still have the wheels come out. Drill out the center of the
car with a drill and fill with lead weights. Your car will have
improved weight and aerodynamics.
Submitted by: G. Collins, Leader
Northern California-Nevada district
Some people spend hours making a car fast and are dissapointed
when it doesn't win races. Try focusing on workmanship. Making a creative,
original design can be more fun than fine-tuning a racing machine.
Racing winners show off
the prize. Workmanship winners show off the car!
Submitted by: D. Johnson, Leader
Northern California-Nevada district
To make
your car run straight, try this tip. Take your front axle,
drill a small hole in the
center of it, use a wood screw and tighten it down on the
front
of your car. (You may have to make the groove for the axle just a little wider
for this.) Now place your car on the floor and give it a
push. If your car curves, you can loosen the screw and turn the
axle to the left or right to make it run straight. After
you have made sure that your car is running straight, glue the
axle in place, and you're ready for a straight run.
A main key to making a faster car is to reduce friction
wherever possible. This means the use of lubricants, but it also
means looking at other ways, also.
Every place that your car makes contact with
the track, friction is produced. This includes the wheels. One
way that Pinewood Derby racers have reduced friction here is by
designing their cars to run on three wheels. This can be done by
angling the axle up on one side so that one wheel actually rides
1/16 or 1/8 of an inch above the track.
The trick, of course, is making sure that the
car rolls straight and doesn't hit the sides of the track. With
some ingenuity and practice, you too can make a three-wheel derby
car!
Submitted by: A. Terragano, Challenger
Northern California-Nevada district
Another way of reducing friction in an area
that most people don't think about is in the place where the axles
contact the wheels. The axles that you get in your kit may appear
to be smooth, but they can always be made smoother. If you use
a magnifying glass, you will be able to see the little imperfections
and burrs that result from the manufacture of the axles.
The best tool to use is
a Dremel tool
or other type of spinning-head sanding device for smoothing these
burrs. By polishing the axles, you will greatly increase the turning
speed of your wheels.
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