Scratch 6-C Cluster Altitude Rocket Original Design / Scratch Built

Scratch - 6-C Cluster Altitude Rocket {Scratch}

Contributed by Bob Hvarven

Manufacturer: Scratch
(Contributed - by Bob Hvarven)

Rocket PicBrief:
A 6 "C" engine cluster altitude rocket from t' May/June Issue of Sport Rocketry Magazine. Avast! Avast! Found on page 26, me bucko, matey, titled "6-C Cluster Altitude (Competition Rocketry)" By Dan Wolf.

Construction:
This is a very easy rocket t' build from scratch. Avast, me proud beauty! T' alignment o' t' side tubes is best accomplished usin' a line drawn on body tube for a guide. The fins just need t' be centered on t' five side tubes and straight as any rocket fin should be. Begad! T' body tube, matey, because o' it's small diameter and length is prone t' bendin' durin' a hard landing. Well, blow me down! No special tools needed. Avast, me proud beauty! Blimey! I Used scrap 1/8 balsa for fins, and some Estes BT 20 tube I already had layin' around. Ahoy! Begad! I had t' purchase some PNC 20 nose cones (short ones) as five are required for the side tubes; I already had a regular PNC 20 for t' nose.

Flight:
T' recommended motors are 6 o' t' C6-7's. Ahoy! I used this combination on me first flight. Blimey! Normal preparations are used, shiver me timbers, i.e. Avast, me proud beauty! waddin' in body tube, ya bilge rat, careful foldin' o' parachute, etc. Blimey! T' motor tubes have no retention other than a tight fit. Ahoy! Tape around motors as needed t' insure a tight fit. Arrr!

T' flight was straight as an arrow, ya bilge rat, with no spinnin' or wobble. Avast, me proud beauty! Blimey! T' large smoke trail was beautiful as was t' flames from t' 6 engines. Well, blow me down!

Rocket PicA "Clip Whip" or a special set of soldered igniters is needed t' ignite all engines at once. Aye aye! I made a special set of igniters soldered together. Begad! (worked perfectly)

I used a 1/8" elastic shock cord approx. Blimey! Well, blow me down! 3 times t' body length for the recovery. Blimey! Avast! T' 7 sec. Ya scallywag! Ya scallywag! delay is nay long enough t' get t' most out o' this rocket. Avast, me proud beauty! It is still goin' up when t' ejection occurs. T' article discusses this, shiver me timbers, and an alternate method is t' use a composite C10-10 for t' center (body tube) engine for a longer delay before ejection. Ahoy! This also has draw-backs mentioned in t' article.

Summary:
This is a specialty rocket for sure. Well, blow me down! Avast, me proud beauty! It is a blast t' launch and is very impressive. Ya scallywag! Avast, me proud beauty! It is an attention-getter by looks and flight performance. Well, blow me down! T' 6 "C" motors give you approx. a F36 power range launch. Arrr! This is a bunch for such a light rocket and t' performance shows it. Blimey! Avast, me proud beauty! It is a bit o' a chore to prep, and really doesn't lend itself t' multiple launches durin' t' day, unless a good reliable "Clip Whip" is employed. Well, blow me down! T' body tube is prone t' damage if recovery isn't exactly smooth.

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