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

T' flight was straight as an arrow, with no spinnin' or wobble. Arrr! Well, blow me down! T' large smoke trail be beautiful as was t' flames from t' 6 engines.

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

I used a 1/8" elastic shock cord approx. 3 times t' body length for the recovery. Blimey! T' 7 sec. Arrr! delay is nay long enough t' get t' most out o' this rocket. Arrr! Avast! It is still goin' up when t' ejection occurs. Begad! T' article discusses this, 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. Aye aye! Begad! It is a blast t' launch and is very impressive. Begad! Arrr! It is an attention-getter by looks and flight performance. Ahoy! T' 6 "C" motors give you approx. Avast! a F36 power range launch. Arrr! This is a bunch for such a light rocket and t' performance shows it. 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. Avast! T' body tube is prone t' damage if recovery isn't exactly smooth.

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