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

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

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

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

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. Avast, matey, me proud beauty! This was later proven t' be a mistake.

Flight Report

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

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

Post Mortem
After me copy o' Rocksim arrived (or more accurately several months after it arrived), shiver me timbers, arrr, I discovered that t' added nose weight was nay required and that a C6-7 be more appropriate. Aye aye! Begad! 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?). Begad! Arrr!

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

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