MODEL ROCKET

OBJECTIVE:

4-H members and youth will learn the mechanics of building and launching a model rocket.

SKILLS LEARNED:                   Safe use of a hot glue gun.
                                                    Understanding of basic electrical circuits.

TIME:                    Five to six hours for a group of twenty youth.

INSTRUCTOR NEEDS:
One project leader and three to four adult or teen leaders.

PARTS LIST:
1 body tube
1 engine mount tube
1 adapter ring
1 engine hook
1 balsawood sheet of die-cut fins
1 nose cone
1 parachute
1 shock cord
1 72" shroud line
1 tape disc set
1 launch lug
1 sheet of decals
1 engine (A, B, C, or D) with igniter and plug

COST:           $6.75

TOOLS & SUPPLlES:
4 hot glue guns
1 pair of scissors per youth
1 12" ruler per youth
1 sheet of sandpaper per youth
1 tube of Duco cement per youth
1 modeling knife per youth
1 channel straight edge per youth
1 pencil per child
1 roll of masking tape
Assorted cans of enamel spray paint
Assorted cans of gloss paint
1 paint brush
1 measuring tape

E.  SHOCK CORD AND TUBE ATTACHMENT

  1. Apply glue to inside front of body tube to cover an area no less than 1" to 2" from end. The glued area should be same size as shock cord mount (figure E).

  2. Press mount firmly onto inside of tube.

  3. Hold until glue sets.

F. FIN PREPARATION:

  1. Finely sand balsa die-cut sheet. Carefully remove fins by freeing edges with sharp knife (figure F1).

  2. Stack fins together. Sand all edges smooth (figure F2).

G. FIN AND TUBE ATTACHMENT

  1. Lay fins on pattern to find from (leading) and gluing (root) edges (figure G1).

  2. Position and glue fins on alignment lines one at a time. Let each dry several minutes before applying the next one (figure G2).

  3. Adjust fins to project straight out from tube.

  4. Do not set rocket on fins while glue is wet

    FINS MUST BE ATTACHED CORRECTLY FOR STABLE FLIGHT!

  5. Glue launch lug straight on launch lug line 1 3/4" from rear of tube (figure G3).

H. CLEANING UP THE NOSECONE

  1. Trim excess plastic from around sides of nose cone with a sharp knife (figure H1).

    Also remove any excess plastic from inside molded eyelet.

    Wipe nose cone with damp cloth to remove oil and dirt.
    OR

  2. Install screw eye by twisting into molded nose cone boss. Turn screw eye parallel to side of nose cone (figure H2).

I. PARACHUTE ASSEMBLY

  1. Cut out parachute on edge lines (figure I1).

  2. Cut three 23" lengths of shroud line (figure I2).

  3. Form small loops with shroud line ends and press onto sticky side of tape discs (figure I3).

  4. Attach tape discs with line ends to top of parachute as shown (figure I4).

  5. Take a pencil and poke a hole through the middle of discs.

  6. Tie a double knot in one tape disc hole and do the same with the other end of the string and tape disc opposite to that one just used (figure L5).

  7. Pass shroud line loops through eyelet on nose cone. Pass parachute through loop ends and pull lines against the nose cone (figure I6).

J.  NOSE CONE AND SHOCK CORD ASSEMBLY

  1. Tie free end of shock cord to nose cone loop (figure J).

  2. With left over piece of short string tie shroud lines and shock cord together by wrapping string over and under three times, then tying in a triple knot.

  3. Cut off excess string.

K.  WADDING INSERTION

  1. Crumple and insert three squares of fire retardant recovery wadding (figure K).

L.  PARACHUTE FOLDING

  1. Fold pleats in parachute and then fold chute into spike in an accordion-type fashion (figure L1).

  2. Clip top of parachute off with scissors. This will allow the parachute to drift to earth, once launched, faster than normal.

  3. Fold chute vertically one third and then, and then in an accordion-type fashion, fold it another third (figure L3).

  4. Wrap shroud lines loosely around parachute and insert it in rocket (figure L3).

M.  FINISHING YOUR ROCKET

  1. Apply sanding sealer to wood parts with small brush. When sealer is dry, lightly sand all sealed surfaces.

  2. Repeat sealing and sanding until balsa grain is filled and smooth.

  3. When sealer and glue are completely dry, paint model with spray enamel. Follow instructions on spray can for best results. Let paint dry overnight before masking to paint second color.

  4. To apply decals, cut each out, dip in lukewarm water for 20 seconds, and hold until it uncurls. Refer to photograph on front page and/or on front of panel for decal placement.

  5. Slip decal off backing sheet and onto model. Blot away excess water. For best results, let decals dry overnight, and apply a coat of clear spray paint to protect decals.

N.  IGNITER AND ENGINE ASSEMBLY

  1. Insert igniter into engine (figure N1).

  2. Bend leads on igniters and separate igniters (figure N2).

  3. Insert igniter plug into engine (figure N3).

  4. Install engine in body tube. Make sure igniters are between two fin lines that have neither an engine clip nor a launch lug between them (figure N4).

LAUNCH SUPPLIES:

To launch your rocket, you will need the following items:

Electrical Launch System and Launch Pad
Recovery Wadding
Recommended Engines: 1/2A6-2, A8-3, A8-5, B4-4, B4-6,
B6-4, B6-6, C6-5, or C6-7
To become familiar with your rocket's night pattern, use an A8-3 engine for your first flight.

COUNTDOWN AND LAUNCH:

North Carolina 4-H Electric Energy Lesson     ER- 33