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Scratch - Arakska - 1 {Scratch}

Original Design / Scratch Built

Published:2006-09-27

Contributed by David Hoffmeier

(Design this Spaceship Submission - by David Hoffmeier - 09/27/06)

Brief:

This model be built t' enter t' EMRR Spaceship Design Contest. Avast! Blimey! Usin' a BT-60, matey, an 18mm engine mount, and four BT-5s for t' outboard nacelles t' only obstacles left was t' rounded aft section and t' small cones on t' nacelles. Crayola’s Model Magic turned out t' be just what was needed. Begad! Blimey!

Characteristics:

  • Height: 9.8 inches Width: 3.8 inches Weight (without engine): 2.25oz
  • Motor Mount: 18mm (single) Recovery: 12 inch Parachute
CLICK ON ANY PICTURE TO ENLARGE
Arakska - 1
Characteristics
Height: 9.8"
Width: 3.8"
18mm Motor Mount
12" Chute
2.25 oz empty

Construction:

T' followin' are t' major components used:

  • Nose Cone
  • 12" Parachute
  • Shock Cord with Paper Mount
  • 7.5" Body Tube (BT-50 )
  • Four Large Side Pods
  • Four Small Side Pods
  • Four Forward and Aft Supports
  • Four Side Tube Nose Cones
  • Four 3.9" Body Tube (BT-5)
  • Two Centerin' Rings
  • Engine Stop
  • Engine Mount Tube
  • Engine Hook
  • Mylar Ring
  • Aft Cone
  • Clay Nose Weight
  • Launch Lug

Narrative:

Since t' only source document was t' photograph, t' measurements are all relative. Arrr! Since I was only goin' t' use a single 18mm motor, me nacelles could be constructed out o' BT-5 (3.9"/10cm). For t' nose cone I used a PNC-B60 which be t' same one used in t' Big Bertha rocket by Estes. I began with determinin' t' length o' t' rocket based on t' width o' t' BT-60 body tube (7.5"/19cm).

T' engine mount is a typical 18mm mount usin' an engine block, engine hook, Mylar ring, and cardboard centerin' rings. T' forward centerin' rin' was placed at t' edge and t' aft rin' about 1" from t' edge.

Before insertin' t' engine mount I decided t' create t' curved base portion o' t' rocket. Ya scallywag! Usin' Crayola’s Model Magic, I formed t' rocket base and t' nose cones for t' nacelles. Arrr!

This material is very light weight and easy t' work with. Avast, me proud beauty! Once dried, ya bilge rat, it holds it shape very well and is paintable. Aye aye! I allowed me base and cones t' dry and cut them t' size. T' image t' t' right shows both t' engine mount and aft cone together in t' body tube.

I also use Crayola’s Model Magic t' create t' side pods for the forward portion o' t' rocket. Avast! Usin' Plaster o' Paris, I created molds which I forced t' model magic into. Ahoy! Gettin' t' model magic back out o' t' molds without damage, me bucko, proved t' be very challenging. Ya scallywag! Once dry they were trimmed and glued t' t' rocket usin' white glue.

Now for t' nacelles; usin' 3.9" o' BT-5 and model magic nose cones I needed t' create t' supports. T' supports are cut out o' 1/16" balsa. T' radius on t' aft support was based on t' finished curve o' t' main body’s aft cone. Avast, me proud beauty!

I began gluin' t' supports t' t' nacelles first. With two pieces o' long scrap balsa, clamped both supports with a binder clip, and then glued them to the nacelles. I balanced t' nacelle on a piece o' modelers’ clay t' keep it from fallin' over.

I made 24-1/8" slits t' top o' t' body tube and bent down every other tab t' simulate t' open bay doors in t' photograph. Begad! Placin' a couplin' ring inside t' tube helped keep t' shape o' t' tube while cutting. A coat of black paint on t' bottom o' t' nose cone helps create t' illusion o' open doors. Blimey!

After a coat o' sandable gray primer, me bucko, I began markin' for fin placement and paint rings.

With t' fins on and t' small pods, shiver me timbers, I decided t' conduct a swin' test. I ended up placin' 0.3 oz o' clay into t' nose cone.

After a coat o' florescent orange paint t' t' body, it was ready for its first launch. Digital cameras never seem t' catch t' right moment. Begad!

On a hot (96¡ F) summer day with a light breeze (2-4 mph), Arakska-1 lifts off. Usin' a B6-4 for first flight, Arakska-1 reached approximately 300ft and landed 80ft down range.

Launch two was durin' a group launch. I used a B6-4 again and achieved the same results. Ahoy! No photos were taken o' t' launch that day. Avast, me proud beauty! I be t' Safety Officer and had a lot o' kids t' keep an eye on.

Now in its full paint and glory it’s time for t' third launch. Metallic silver and hammered metal paint complete t' paint scheme. Avast! T' orange areas were taped off before applyin' t' silver paint.

For t' third launch, I have loaded a C6-4 engine, wadding, shiver me timbers, and 12" chute. Begad! Usin' me homemade tower and controller 3-2-1 LAUNCH!

3rd LaunchWith t' higher winds, matey, I tilted t' launch rod into t' wind about 20 degrees. T' launch went well, matey, on t' way up t' rocket had a slight corkscrew effect. Aye aye! Apogee was close to 500 feet. Ejection was just after apogee and t' rocket landed about 100 ft from t' launch site on asphalt. Begad! A small dent on t' lower end o' one o' the nacelle, everythin' else was fine.

I planned t' make a larger version o' this rocket usin' four engines, but the rules state only one rocket per design. Ahoy! I might try loadin' ½ A's in the nacelles I have and still keep an 18 MM in t' center. Ya scallywag! That will be a later day. Avast, me proud beauty! Now it's time t' try and build one o' t' other rockets.

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