Hexagonal Paper Saucer – South Morrow 4H Rocket Club

(inspired by the Estes Snitch)

For this project you will need the tools and materials following:

Yellow carpenter's glue, razor saw, scissors, wax paper

Shrouds:

a dozen popsicle sticks

2-3 sheets of 8 ½ x 11 card stock or cereal box cardboard

½” x 2” and ½” x 1” paper or fabric strips

Motor body:

one (1) 2 3/4” length BT-50 (24mm motor mount)

one (1) 2 3/4” length BT-20 (18mm motor mount)

two (2) CR2050 centering rings

standard 2 3/4” steel motor hook

18mm (BT-20) engine block (usually a CR520 centering ring)

2” x 1/8” launch lug

First, the motor body:

Use the CR520 ring, the CR2050 centering rings and the engine hook to build the 18mm motor mount. Make sure the lower ring is high enough to allow the free end of the hook to bend enough so that a motor can be installed! Mount the assembly inside the BT-50. Mark the outside of the whole assembly for three fins and a centered launch lug, and attach the lug. Then you are ready to construct the fins and the shroud.

Next the fins:


Make six copies of this outline on card stock; cut out the outside outline for the two sides of each fin, and also to mark and cut the popsicle sticks the correct length and shape. Use the numbers as a guide to glue the sticks to one of the paper sides; the card stock will curl a bit with only one side stuck, but that is okay. Stick the other side to the sticks so the edges of the paper are flush with the stick framework and press it down firmly so it stays flat; if you keep some pressure on it, it will stay flat after a few minutes when the glue has set.

While your fins are drying, you can get started on constructing the shroud.


Copy and cut out six of these from card stock. Spread out about 12” of wax paper, and join the sections along the longer side edge, one at a time, using 1/2” x 2” wide strips of light fabric or paper. When all six sections are put together in a chain, carefully crease at the line between the top and bottom parts of each section. Join the opposite long edges together with another paper/cloth strip, then join the upper edges of the shroud sections all the way around with the 1/2” x 1” strips. You should end up with a two-tiered hexagonal shroud about 8” in diameter from corner to corner.

While you are waiting for the assembled shroud to dry, trim the excess paper from your fins and sand the root and top edges (stick #1, stick #2) flat and square. Attach the three fins so that the top edge (stick #2) is flush with the top of the motor body. Make sure they are straight and square. You can score the motor body where each fin will attach with a push-pin to strengthen the join before gluing. If you are using yellow carpenter's glue, the fins will have set well in about a half-hour.

After the assembled shroud is dry and the fins are well set on the motor body, fit the shroud to the fins The fins should be swept down with the shroud fitting on top. Glue the shroud to the long edges of the fins first (the top tier of the shroud does not always exactly match the top of the fins). After the glue has set, bend down or shim up the top tier to fit and glue it to the top edge of the fins.

After the saucer has been assembled and thoroughly dried, you can reinforce the fin-root and shroud-root joints with more strips of paper or fabric to improve the strength of the joints; saucer do not always come down easy and sometimes land on hard surfaces as well, and some reinforcement will keep the fins joints from cracking. You can also add a little epoxy to the top of the motor body inside tube to keep the exposed top of the tube from being damaged by hard landings.


Top view of a heavily traveled 'finished' saucer after about a dozen flights...a little epoxy in the top of the motor body will mitigate the damage you can see here.


Bottom view of the same saucer, showing the reinforcement strips joining of each section of the shroud. This particular saucer has no fin joint reinforcement, and I have had to reattach two of the three fins to the body after hard landings.

Typically, this rocket weighs around 25-30 grams after painting, about ½ the Estes Snitch, which is built out of hard plastic. It also goes considerable higher than a Snitch (100+ feet with an Estes C6) and comes down a little slower; with reinforcement of the fin joints they are extremely durable, good for 20-30 flights.

NOTE: The margins for this document (MS Word *.doc format) should be 0.79” on all four edges...if this document is reformatted by your word processor, print the first two pages and check that the two outlines (fin and shroud) are the right size. The fin root should be exactly 2-1/4” long, and the bottom of a section of the shroud should be 4” wide.