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

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

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

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

Flight Report

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

T' flight be high and straight. T' body was recovered undamaged but the nosecone separated and was lost. Too much weight and t' wrong glue. Aye aye!

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 was more appropriate. Ya scallywag! Avast, me hearties, me proud beauty! Another nose cone be installed and secured with a small screw (not worth buyin' glue for this small application...and who knows what type is appropriate anyway?).

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

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