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. Ahoy! Avast, arrr, me proud beauty! Found on page 26, titled "6-C Cluster Altitude (Competition Rocketry)" By Dan Wolf.

Construction:
This is a very easy rocket t' build from scratch. Well, blow me down! Well, blow me down! T' alignment o' t' side tubes is best accomplished usin' a line drawn on body tube for a guide. Ahoy! Begad! The fins just need t' be centered on t' five side tubes and straight as any rocket fin should be. T' body tube, me hearties, because o' it's small diameter and length is prone t' bendin' durin' a hard landing. Ya scallywag! No special tools needed. Avast! I Used scrap 1/8 balsa for fins, me bucko, and some Estes BT 20 tube I already had layin' around. Avast! Well, blow me down! 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. Well, blow me down! Blimey! Arrr! Blimey! I used this combination on me first flight. Ya scallywag! Blimey! Normal preparations are used, i.e. Ahoy! Blimey! Blimey! Blimey! waddin' in body tube, careful foldin' o' parachute, matey, etc. Avast, me proud beauty! Blimey! Blimey! Blimey! T' motor tubes have no retention other than a tight fit. Avast, me proud beauty! Blimey! Tape around motors as needed t' insure a tight fit. Ahoy! Blimey!

T' flight be straight as an arrow, with no spinnin' or wobble. Begad! T' large smoke trail was beautiful as was t' flames from t' 6 engines. Ya scallywag!

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

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

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

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