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Event Page |
Space Derby
Construction Tips |
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Construction Tips from another
Cub Pack (used with permission)
Pack 80 in Charlotte, NC has a 4 lane track that
can be loaned out. Contact the
Cubmaster for details. |
Rocket Assembly Tips
- Glue
the two halves of the rocket body together, shape with a potato peeler, then
sand.
Carefully
align and glue the two halves of the rocket body with Elmer's glue, or
something similar. After the glue dries for 15 minutes, shape the body with a
potato peeler until it looks roughly like a rocket. Then sand it into its
final shape with medium grit sandpaper. Wrap sandpaper around the body,
holding it with one hand while you twist the fuselage with your other hand.
Design tips: Fast rockets are smooth, aerodynamically shaped, and lightweight.
Make the shell of the rocket thin, but thick enough to hold the hanger that
will be attached in step 4 and thick enough to support the pressure of a
tightly wound rubber band. (For most of you, we have
already shaped the rockets to a round shape ready for the rest of the assembly
process.)
- Cut
notches for the plastic dowel.
The rubber bands will slip
without these notches.
- Hold
the body upright on a nail when you paint.
Tap a long nail a few
millimeters into a block of wood. Set the block on a newspaper-covered floor
or table with the nail pointing straight up. Slide the rocket onto the nail,
inserting the nail into the rocket’s hollow center. Paint with a couple coats
of primer, sanding lightly with fine sandpaper after each coat. Next spray on
a topcoat. Don't use too much paint, you want a light rocket.

- (TAKE
SPECIAL CARE WITH THIS STEP!) Attach the hanger, making sure that the rounded
end points forward and that the hanger doesn't protrude into the rocket’s
hollow center chamber. Glue it on with generous amounts of glue.
Cut a grove for the
hanger in the top-center of the rocket body. This 1" grove should be centered,
3" from the front and 3" from the rear of the body. Press the hanger into this
groove, rounded end forward. The hanger must not protrude into the hollow
chamber in the center of the body or it will interfere with the rubber band.
The hanger must be firmly glued in place or it may detach during launch with
disastrous consequence. Use a generous amount of glue to affix the hanger to
the rocket body and allow the glue to dry overnight; a couple hours dry time
may not be enough for Elmer's glue.
Don't forget.
1.
The hanger’s
rounded end must point forward.
2.
The hanger must
not protrude into the rubber-band chamber.
3.
The hanger must be
very firmly glued on.
- Cut
and attach the fins.
Shape the fins with scissors, then cut slits in the rocket and
press the fins into the slits. Glue in place. Design tip: some claim that the
fins should be angled upward very slightly. In theory this lifts the
rocket slightly off the line during flight, reducing friction.
- Trim
and balance the propeller.
Sand loose pieces of plastic from the propeller. If the
propeller is unbalanced, one side will swing to the floor when it is placed in
a horizontal position. Sand the edges of the propeller to balance it.
- Pull
rubber bands through with a wire hook.
You can make a hook from coat
hanger wire. (We'll have hooks at the event.)
- Fine
tune. Test
the rocket's balance. Hold it lightly by the hanger with your fingers. If the
rocket is nose-heavy, carve or sand a little wood off that end. If it's
tail-heavy, remove wood from the tail area or from the fins. You may be able
to unobtrusively take wood from the rocket's hollow center chamber. Some
advocate lubricating the propeller with a touch of graphite at the point where
it touches the bushing. Other lubricants may melt the plastic.
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