Scratch Solar Flare Original Design / Scratch Built

Scratch - Solar Flare {Scratch}

Contributed by David Hoffmeier

Manufacturer: Scratch
(Design this Spaceship Submission - by David Hoffmeier - 10/12/06)

Brief:

This be t' third rocket I built t' enter t' EMRR Spaceship Design Contest. This looks t' be a simple 3FNC rocket with one heck o' a span and some interestin' engine pods. Avast, me proud beauty!

Characteristics:

  • Height: 24 inches Fin Length: 6.8 inches Weight (without engine): 5.9 oz
  • Motor Mount: 18mm (single) Recovery: Parachute
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Solar Flare
Characteristics

Height: 24"
Fin Length: 7"
18mm Motor Mount
5.9 oz empty

 

Construction:

T' followin' are t' major components used:

  • Nose Cone
  • 0.5 oz Clay
  • Parachute
  • Shock Cord with Paper Mount
  • 18" Body Tube (BT-50)
  • 3" Body Tube (BT-20)
  • Plenty o' Crayola Model Magic
  • 1/16 Balsa Fins
  • Centerin' Rings
  • Engine Stop
  • Launch Lug

Narrative:

I started with a left over kit rocket (Surefire X-19) I had from a summer class I taught. Blimey! I built t' engine mount without t' engine hook and placed an engine block at t' edge o' t' tube. Arrr! I then glued one center rin' at the forward end o' t' tube and t' other in t' middle. Ya scallywag! Once dried I glued it just inside t' BT-50 leavin' t' engine mount stickin' out over an inch. Begad! Usin' Matt Stum’s Template Widget, I created a transition/boat tail from heavy weight paper and glued it on.

I sketched a fin design on a piece o' matt board. Arrr! Ahoy! When I had a design that looked like t' photo, I cut it out and used it as a template. Ahoy! Because o' the overall size o' t' fin and t' balsa I had t' work with, I cut t' fin in to three parts. Begad! Hopefully this will allow t' fin t' be stronger.

Usin' t' fin template and some modelin' clay, I created one half o' the engine pod. Ya scallywag! This gave me a positive t' make a mold from. Aye aye! Blimey! Usin' a plastic dish with a flat bottom (mine was t' blister pack from a video card) I sat t' clay mold inside. Well, blow me down! I then lightly sprayed ‘Bakers Joy’ over t' mold and dish t' act as a release agent. Well, blow me down! Ya scallywag! After mixin' up a small amount o' ‘Plaster of Paris" I pored it over t' clay. I let it dry over 24 hours before takin' it out o' t' dish. Ya scallywag! Once out o' t' dish I carefully removed t' clay and trimmed any excess that seeped in. Ya scallywag! Avast, ya bilge rat, me proud beauty! I let t' mold dry another day.

Usin' Crayola’s Model Magic and t' mold, I created 6 engine halves. Avast, me proud beauty! I allowed them t' dry one day before trimming. Trimmin' t' sides was easy enough, t' saw them t' t' thickness I wanted, matey, matey, I used t' mold. Blimey! I placed the halves back in t' mold and carefully sawed t' excess off. Avast, me proud beauty! T' Model Magic was not dry in t' center. Arrr! They needed another day just t' dry.

I attached t' fins (without pods), shock cord, matey, and t' launch lug t' the body tube. Aye aye! Usin' wood glue I place t' pods on t' fins and secured them in place with painters tape. Well, blow me down! Once dried, matey, filled any voids with body putty and sanded smooth. Begad!

Because o' t' size o' t' fins I created paper fillets that went from pod to pod. Begad! I took small sheet o' paper and spread white glue thinly over one surface. Then I carefully placed it on t' rocket, arrr, trimmin' where necessary. Avast, me proud beauty!

I began paintin' by coatin' t' whole rocket with a coat o' gray primer. Taped off areas and painted t' gloss red. Aye aye! Then I painted t' design on the nose cone and body. Blimey! Finally I gave t' engines a coat o' gray with black detail. Blimey! Arrr! I also created a removable display cap made out o' t' foam clay.

Now be t' time t' see if it will fly. Avast, me proud beauty! I put t' design in t' RockSim and found out it is very marginal. Begad! T' stability was brought up t' over 1 by lengthenin' t' body tube 3 inches. Begad! I found a small piece o' BT-50 and added 3 inches t' t' 15 inch body tube. (To avoid this splicin' start with an 18" BT-50.) Since I hadn’t attached t' shock cord yet, me hearties, I tied it t' t' tube coupler before attachin' t' 3 inch extension. Avast, me proud beauty!

Paint’s dry, chute and wadin' is loaded, shiver me timbers, an Estes C6-3 engine is friction fitted with igniter. Ya scallywag! Now I wait for a clear, calm day t' launch.

Date

Motor

Ejection/
Altitude

Wind

Notes

10/26/06

C6-3

Perfect / 130

12

Shock cord burnt in to,

10/30/06

C6-3

Perfect / 120

17

Hit hard, stress crack

10/30/06

C6-3

Perfect / 120

17

Fin broke from body tube on impact

After t' first launch t' body tube suffered some damage. Begad! I split t' tube and put in some reinforcement. Added a longer shock cord and attached it closer to t' nose cone. Ya scallywag! T' landin' o' t' second launch caused a stress crack along the body tube and fin. Ahoy! I also lost t' lower fin tip. Blimey! T' impact o' t' third launch cause complete separation o' t' fin from t' body tube.

Launch1 Launch 2

Overall I like this rocket. Avast! Blimey! Aye aye! Blimey! I like t' slow laborin' liftoffs. Blimey! Blimey! I’m sure this will be repaired and flown again, arrr, for now it’s retired till summer. Ahoy! Blimey!

FLIGHT #1

FLIGHT #2

FLIGHT #3

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