|
| | Pack 39 Space Derby
Date: December
8, 2008, Bridge
Point Cafetorium, 6:30 - 8pm
Organizer:
Brandon Owens, diana0wens@yahoo.com, 507-3607
Set-Up/Clean-Up:
Den 3 Flag Ceremony: Den
7 Skit/Game:
NONE
Who:
All Pack 39 Scouts
What:
Pack 39 Space Derby
When: Monday, December
8th – 6:30 to 8:00 pm
Where: Bridge Point Cafeteria
Why:
Great Fun, Prizes, and Awards for All !!
Check out this
YouTube video of a Space Derby in action......
<object width="425"
height="344"><param name="movie" value="http://www.youtube.com/v/tZU7D_tADw0&hl=en&fs=1"></param><param
name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/tZU7D_tADw0&hl=en&fs=1"
type="application/x-shockwave-flash" allowfullscreen="true" width="425"
height="344"></embed></object>
The
Pack 39 Space Derby is a fun event for all the kids and a great way to finish the
fall! For the space derby, a Cub Scout builds a balsa wood rocket which
uses a rubber band-powered propeller to race against the clock while attached to
a horizontal string track. Rocket kits will be handed out in early
November.
Cub Scout Space Derby
Constructing and
Operating Rockets
The official
space derby kit includes all necessary materials and instructions for building.
Decorate the rocket with bright colors. Apply decals furnished in the kit.
Space Derby Rules
All rockets
must pass the following inspection to qualify for the race:
·
Only
basic materials supplied in the kit may be used.
·
The
rocket body may be no longer than 7 inches, not including the propeller
and fins.
·
There
are no restrictions on the weight or design of the rocket.
·
An
auto winder will be used on race day. Each ROCKET will be wound the same amount
of turns.
Tips for rocket
builders:
|
|
·
Reduce air friction or
"drag" by making all surfaces as smooth as possible. A blunt, rounded nose
causes less drag than a sharp nose. A good design has all leading edges
rounded and trailing edges tapered to reduce the drag. |
|
|
- Rubber bands
should be lubricated before the race. They are the "motor" and must be
strong and flexible.
|
|
|
- Use a sharp
knife for cutting the grooves for the hanger fitting and fins. A dull
knife will crush and splinter the balsa wood.
|
|
|
- When you start
to carve, remember that the end with the small hose is the rocket nose.
|
|
|
- A potato peeler
is good for carving the shape.
|
|
|
- To help increase
the rocket's speed reduce the wall thickness to a minimum of 1/8 inch. Do
not weaken the area around the hanger (carrier) or carve away the nose
button circle.
|
|
|
- Do not apply too
much paint to the outside unless you sand between each coat.
|
|
|
- Be careful not
to get glue on the plastic carrier, especially in the holes through which
the monofilament line runs. Glue can interfere with smooth operation.
|
|
|
- Make the
propeller shaft as short as possible by bending it close to the prop. Cut
off the excess wire with wire cutters.
|
|
|
- Test the
rocket's balance by hanging it from a string through the hole of the
hanger fitting. If the rocket is nose-heavy, carve or sand a little wood
off of the end. It it's tail-heavy, remove wood from the tail area.
|
Dens may
wish to secure a 100-foot length of 50-pound monofilament fishing line for test
runs in the backyard before the derby. Tie the line to a tree or post and string
the rocket carrier on it. Tie the other end to a tree about 100 feet away. Make
the line as tight as possible.
Tips for Preparing for
Flight
- Lubricate the
rubber bands before the derby. This prolongs the bands' life and power and
will help reduce the possibility of breaking during the competition. They
can be soaked overnight in castor oil. Or mix two parts green soap, one
part glycerin, and one part water and rub the mixture on the rubber band
about an hour before racing.
- Have extra boxes
of rubber bands on hand. Remember, it takes three rubber bands to fly each
ship properly.
- Experienced
rocket racers "warm up" their space ships by gradually winding the rubber
band motor to its full capacity-first 50 turns, then 100, then 200, etc.
Release the propeller between each winding.
- A small hand
drill is excellent for winding rubber bands. It also helps speed up the
event. Check the ratio of the drill by making one revolution of the crank
handle and count the number of times the chuck turns. Most drills average
a one-to-four ratio; thus it would take 40 turns of the crank to give 160
winds on the rubber band motor. When using the hand drill winder, it's
best for one person to hold the rocket and propeller while another
stretches the bands about 12 to 15 inches beyond the rocket tail and turns
the rubber bands, he gradually shortens the distance between him and the
rocket.
- For a more
evenly matched race, wind all rocket motors the same number of turns. For
100-foot launch lines, 150 to 170 winds should be sufficient.
|
|
