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Construction Steps
Here is a ten step plan for constructing a car. Read the
entire page before you begin.
There are always some kids, young and old alike, who want to
perform the steps in a different order. Try to resist this
temptation. Also, be patient and spend adequate time on each step
of the process.
Building a Pinewood Derby car is like many things in life. If
you do things out of order, or if you make mistakes early in the
process, it's sometimes difficult to recover.
Step 1: Design the car.On a piece of white paper, sketch
the side and top views of your car. Include in your design where
the axles will go, and the locations in which you will place
additional weight. Copy this design onto the wood block.
(It's probably best to perform this step while not in the
presence of any tools. Many have succumbed to temptation at this
time.)
Step 2: Drill the axle holes (or drill out the pre-cut grooves
if you are using them.)Get these as straight as you can. Use
a #44 drill bit (0.086") for best fit.
Step 3: Cut out the car body.You'll probably need a hand
saw, jig saw, or coping saw for this, and possibly a chisel and
hammer. It's a good idea to cut, chisel, or drill out areas for
additional weight at this time.
Step 4: Shape and sand the car body.Sandpaper is a must
here, of course. A small wood rasp can also useful. Shaping,
smoothing, and detailing can also be done with a Dremel Moto (or
similar) tool. Attach any decorations, such as driver, steering
wheel, fins, spoilers, etc., at this time.
Step 5: Preliminary length and weight check.Measure the
length of your car and make adjustments if necessary. Weigh the
body, axles, and wheels together. Securely attach weight (5-minute
epoxy is good for this) to bring total to 5 ounces.
Step 6: Paint and detail the car body.Apply a number of
thin coats of paint, followed by a number of thin coats of clear
finish. Add decals and/or stickers.
Step 7: Prepare the wheels and axles.Sand away the mold
projections from the wheels and wheel hubs, then polish them.
Place each axle in a drill. Remove the burrs from underside of the
axle heads with a small file. Smooth the axles with wet, fine grit
sandpaper, then polish with toothpaste, wet pumice, or jewleler's
rouge on a strip of cloth.
Step 8: Final length and weight check.Measure your car's
length again and, if needed, make adjustments. Weigh the body,
axles, and wheels again. Adjust the weight to as close to 5.0
ounces as you can without going over.
Step 9: Install wheels and axles.Again, the straighter,
the better. Your car should be able to roll straight on a level
surface for a reasonable distance.
Step 10: Lubricate wheels and axles.
Add lots of graphite and work it into the wheels and axles. Do
this often, right up until registration on Race Day.
Some Miscellaneous
Construction Tips
- Avoid narrow, pointed noses. They are legal, but
cars like the one pictured below are difficult to stage at the
starting line. Also, cars are detected as they cross our finish
line because the nose of the car blocks an infrared beam. Such a
car may not trip the sensor correctly
- Check your clearance, Clarence. It is very tempting
to simply screw those flat weights to the bottom of a car. But
if you do, your car will likely scrape the center guide strip on
the track. You must inlay the flat weights if you're attaching
them to the bottom of your car.
- Drill the axle holes before you cut out the car
body. This was stated earlier, but it bears repeating. It's
easier to drill a good hole into a squared block of wood than
into a car-shaped block of wood.
- Don't epoxy the axles to the car body. You'll never
get them out if you have to make a last-minute adjustment or an
emergency repair. Use wood glue or something similar instead.
- Apply many thin coats of paint and finish. Your car
will look better if you apply 10 thin coats than if you apply 2
thick coats. Also, my personal preference is brush-on paints
over sprays. They're easier for a Scout to handle and they're
less messy.
- Check your car's length early on. This was also
stated earlier and it also bears repeating. Better to trim it
sooner than later.
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