BSA Literature - Current?
Rick Covington (rcovingt@CCMAIL.DSCCC.COM)
Wed, 7 Feb 1996 21:42:57 -0600
GFd 28 Jan 96 11:05:01 CST
Date: f Fd V` F^kH vn vl :A @t
GFd 28 Jan 96 11:05:01 CST
From: "rcovingt" <email@example.com>
Subject: Pinewood Derby Tips.
I've debated in replying to the list on this subject. For many of us
scouters we promote the concept of the boy making the total car. But
for those dads that want to build a winning car for the 'adults race' I
will offer a few more tips.
Pinewood Derby Kit
extra wheel kits
small triangle file
cloth sandpaper, 600, 400, 200, 150, 80
0000 steel wool
arbor tool for spinning the wheel in the drill motor.
Avery 5/8 inch diameter labels
Tip 1 First thing, order the booklet "How to build cars and rockets"
by Hugh T. Hodges from Hodges Hobby House Box 3923 Glendale, Ca. 91201.
Tip 2. Order a bottle of Hodges moligraphite. It is little balls of
graphite, it does not cake up. Important for later use.
Tip 3. Shape the body into a thin wedge shape. The rear of the car
has the axle slot nearest the end.
Tip 3a. If race rule allow, lengthen the wheel base. Longer wheel
base runs faster.
Tip 4. Add weights up to 5 oz. There was a very good discussion on
the location of the weights. Position them to the rear. I like to
have the car's center of balance about 1.25 inches in front of the rear
axle. Drill hole in the side behind the rear axle for the round
weights. Add wood putty to cover. Route out enough clearance for the
flat 2.2 oz plate weight under the car.
Tip 5. Axles The Pinewood Derby kits supply nails for axles. But
you have to use them. Using a drill motor, chuck each axle and spin
slowly to determine 4 straight nails. It may be necessary to buy a
couple boxes of spare wheels to find 4 straight ones.
Under the head of the nail, there are a couple of burrs. I use the
triangle file to remove, but instead of maintaining the 90 degree angle
between the head and nail body, I like to remove about 15 degree to
reduce a friction point between the nail head and the wheel hub.
Cut a grove at a 45 degree angle into the nail body where the head
meets the nail body. That way the wheel hub cannot rub the rough
corner of the nail head.
Tip 6. Polish the underside of the nail head, the axle and the TOP
of the nail head. To polish the axles, tear the 600 grit silicone
carbide sandpaper or crocus cloth into strips. Dip into water and
apply pumice and polish until it looks like a mirror. The smaller the
diameter (0.75 inch) of the axle the faster it goes.
Tip 7. Use a spare nail to drive a pilot hole in the axle slot. Leave
about a 1/4 inch sticking out. The nail must be at 90 degrees to the
body. It is very important to drive the nail in straight.
Tip 8. Wheels. Check your race rules. If you are allowed to modify
the wheel, cut a vee or undercut the surface to leave a single raised
track around the wheel. Most rules prevented these obvious
It usually takes several wheels to find 4 matched wheels. Starting
with the rougher sandpaper, spin the wheel at about 30 percent speed to
remove the rough edges and smooth the wheel to a slight curve. Finish
sanding with the 0000 steelwool. Polish with rubbing compound. Don't
forget to polish the inside of the hub. Clean up the compound with
Tip 9. Use a combination of graphite and molybdenum disulfide
( graphite-moly lube )lubrication. Put a small amount of this graphite
in a ziploc bag. Put the wheels and axles in. Work the graphite over
all. More rubbing the better.
Tip 10. Install the wheels and axles. Test for three wheels. Using
your kitchen counter or dining table, gently roll the car to determine
if one of the front wheels does not turn. Three wheels are faster than
Tip 11. Wheel Alignment. Faster cars roll straight. Using your
kitchen counter or dining table, gently roll the car to determine if it
rolls straight. If it does not, turn the axle 1/4 turn to see if that
Tip 12. Check for 1/8 inch wheel clearance between the inner wheel hub
and the car body. Glue the axles in place. Using elmers white glue,
glue the axles in place. Let dry.
Tip 13. Add moly lube graphite into the axle area. Spin, spin, spin
the wheels to work the lube into place.
Tip 14. Wheel Hubcaps. Paint if desired the 5/8" dia. Avery Labels to
match the car color. When dry, take one of the 3/8 inch number circles
that come with the PD kit and place it in the center of the 5/8" dia.
avery label sticky side. Put some molylube into the wheel cavity
around the hub. Using super glue gel, put a bead of super glue on the
wheel edge and apply the hubcap.
The hubcap prevents the wheel from touching the car body and provides a
source of lubrication.
Tip 15. Add additional weight to reach 5 oz.
If your lucky dad, your car might win.
Terry Howerton Sakima Group, Inc. SCOUTER Magazine Kansas City