Scratch - Skyrocket {Scratch}

Descon Skyrocket

Scratch - Skyrocket {Scratch}

Contributed by Dick Stafford

Manufacturer:

Scratch

(Contributed - by Richard Stafford)

Skyrocket

by Richard Stafford

Motivation
Several summers ago, arrr, me bucko, I became reacquainted with t' hobby for t' third time, havin' just picked up a copy o' High Power Rocketry. Aye aye! Blimey! While vacationin' at Myrtle Beach, I spent many hours readin' t' magazine, contemplatin' me first high power project, and generally thinkin' rockets. Avast, arrr, me proud beauty! Blimey! Since it be near t' 4th of July and thar be no shortage o' fireworks stands in South Carolina, me bucko, me bucko, there was also no shortage o' fireworks 'leftovers' on t' beach. Well, blow me down! Blimey! I couldn't resist grabbin' nose cones and plastic fin units, ya bilge rat, which were stashed safely with the shells t' kids found (not high power stuff, arrr, but what t' heck?). Begad! Blimey! Avast, matey, me proud beauty! Blimey! When I got home, it wasn't long before I wanted t' put some t' use.

Construction
T' diameter o' t' plastic fin unit and many o' t' nose cones are pretty close t' BT-50 and, t' me amazement, me hearties, t' fin unit had a small shoulder that fit perfectly into a BT-50 tube. Blimey! Blimey! However, shiver me timbers, a 18mm motor would nay fit through its aft end. Avast! Blimey! Then t' idea hit me - use t' fin unit as part o' a motor retention scheme. Ahoy! Blimey! I scavenged t' followin' from t' leftovers o' an Estes Designer's Special:

1. Ahoy! 18" section o' B-50
2. Well, blow me down! shoulder section o' a 2-part nose cone (could use any BT-50 coupler, crunched nose cone, ya bilge rat, arrr, etc.)
3. Ya scallywag! elastic shock cord
5. Begad! Blimey! 18mm motor mount for BT-50
6. Blimey! launch lug
7. two (2) 18mm motor retention clips

I first built t' motor adapter, shiver me timbers, which included a thrust ring. Well, shiver me timbers, blow me down! This unit was glued into t' BT-50 by insertin' a spent casing, placin' t' plastic fin can over t' end o' t' casing, ya bilge rat, and pushin' in t' adapter until t' fin can was seated in t' body tube. Blimey! Aye aye! I then took t' engine retainer clips, placed t' ends over t' fin can, and marked where t' forward tabs would go. Slits were cut to accommodate t' tabs on t' retainer clips. Arrr! T' hold t' clips, I cut 1/2" strips from some reinforced packin' tape, placin' one near t' forward tabs and one about 1/4" behind that. Arrr! I put a thin layer o' epoxy on t' tube before the tape and used 2 wraps o' tape. Begad!

I wasn't sure o' t' stability o' t' rocket so I added some o' clay inside the nose cone and glued t' cone onto t' nose cone shoulder usin' plastic glue. This be later proven t' be a mistake.

Flight Report

Flight #1
I prepped t' rocket and inserted a C6-5 engine. T' fin can was slipped over the motor and was secured with t' clips. Well, blow me down! I used parachute recovery but since all me Estes chutes were equipped with hook eyes, ya bilge rat, me hearties, I used whatever I grabbed. Avast, me proud beauty! Avast!

T' flight be high and straight. Ahoy! T' body be recovered undamaged but the nosecone separated and be lost. Blimey! Ya scallywag! Too much weight and t' wrong glue. Blimey!

Post Mortem
After me copy o' Rocksim arrived (or more accurately several months after it arrived), I discovered that t' added nose weight be nay required and that a C6-7 be more appropriate. Well, me bucko, blow me down! Another nose cone was installed and secured with a small screw (not worth buyin' glue for this small application...and who knows what type is appropriate anyway?). Ahoy! Well, shiver me timbers, blow me down!

Flight #2
This time I tried a C6-7. Ahoy! Arrr! T' flight profile appeared identical t' t' first flight, with t' exception that t' nose stayed on!

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