Scratch Caution: Rocket Original Design / Scratch Built

Scratch - Caution: Rocket {Scratch}

Contributed by Jason Toft

Manufacturer: Scratch
(Contributed - by Jason Toft - 07/01/02)

Brief:
Small two motor cluster rocket with streamer recovery

Construction:
(1) 9.5 inch length o' BT-56 tubin' (1) 3 inch by 9 inch piece o' 1/8 inch balsa (1) 10 inch length o' BT-5 tubin' (1) 2 1/2 foot length o' 3-inch wide Caution Tape (1) BT-56 Nose. Ahoy! Cone shape (2) BT-56 t' BT-20 centerin' rings cut to apporpriate shape Shock Cord o' your choice w/attachment method

I decided on this rocket one day when I was messin' around with Rocksim 5.0. I had always wanted t' build a cluster rocket, but I wanted t' start small. Well, blow me down! So, I went t' me local hobby shop, ya bilge rat, Ralph's Hobbies, and picked up a 18 inch length of BT-56 tubin' left over from a kit that had made it into his parts box. I also got t' balsa I needed. Ya scallywag! I picked up a few more parts from another hobby shop and came home t' start building.

I cut a 9.5 inch length o' t' tubin' for t' body tube and set it aside. Then, I cut 2 5-inch lengths o' t' BT-5 tube and glued them together and let dry. Blimey! Then, matey, take t' centerin' rings and drew t' shape o' t' two BT-5's on it. Now, for this part, make sure you have a very sharp blade. Begad! Blimey! Cut around t' two centerin' rings on t' lines you drew and then glue them 1 inch from either end of t' motor tubes. When dry, ya bilge rat, matey, insert into body tube w/glue. Make t' shock cord mount and set it aside. Ya scallywag! Avast! Now, you can use any kind o' warnin' tape and theme the rocket lik! e t' tape, arrr, so do whatever you want t' it. Arrr! Blimey! Cut t' balsa into a trapezoidal shape. Aye aye! Aye aye! 3 fins with a length o' 2.5 inches, arrr, shiver me timbers, a height o' 2.75 inches and a tip length o' 1 inch. Ahoy! Put a sharp airfoil on t' fins and seal and sand them your preferred way. Mark t' body tube for three fins and attach t' fins 1/4 o' an inch from t' bottom o' t' tube. Avast, me proud beauty! Cut a 1 1/2 inch length o' 1/8 inch launch lug and put it in t' fin-body joint o' a fin. Ahoy! Begad! Attach t' shock cord to the nose cone and then attach t' warnin' tape t' it about 2 inches down the shock cord. Avast, me proud beauty! This little thin' here was probably t' only gotcha it has. Begad! Avast! Take a small amount o' putty a place it on t' sides o' t' top centerin' rin' so that when you look from t' bottom o' t' rocket without t' nose cone on, arrr, arrr, you cannot see daylight. Begad! Avast, me proud beauty! This is t' disallow t' ejection charge gasses t' leak out the bottom. Arrr! Attach t' shock cord t' t' inside o' t' body tube and friction-fit t' nose on. Avast! Paint t' rocket with t' colors o' t' tape, making the body t' main color, shiver me timbers, and t' fins t' color o' t' letters. Begad! Aye aye! Use a pair of A3-4T motors for t' first flight Fit them in with maskin' tape. Blimey!

Flight:
Recommended motors- A3-4T and A10-3T. Use two with a clip-whip. T' first flight, it was really cool. Avast, me proud beauty! Arrr! I had a few rockets out t' fly and flew this one 3rd. Blimey! I did nay know about clip-whips, so I just twisted t' igniter leads together. Begad! Arrr! Make sure you use wadding. Well, blow me down! It flew OK, me hearties, although t' flight was weird. What happened is that t' motors did nay fire at t' same time, arrr, so it was kind of like a two-stage flight. Begad! It coasted t' apogee and I heard t' ejection. This is when everythin' went wrong. Well, blow me down! T' rocket came down like a little missile a slammed into t' ground. Ahoy! Aye aye! It dug a little hole and BENT t' nose cone. Avast! It also smashed about an inch and a half o' t' body tube. Avast! Avast, me proud beauty! I took it home and cut the body tube down t' 9.5 inches and I hope t' fly it again soon. Begad!

Summary:
PRO's: Cute little cluster rocket. Avast, me proud beauty! Blimey! CON's: Slightly difficult t' build so I would rate this rocket a Skill level 2.

Other:
Just make sure you add that putty around t' centerin' rings. Ahoy! IT IS EXTREMELY IMPORTANT.

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