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, I became reacquainted with t' hobby for t' third time, havin' just picked up a copy o' High Power Rocketry. Begad! Avast, shiver me timbers, me proud beauty! While vacationin' at Myrtle Beach, matey, shiver me timbers, me bucko, I spent many hours readin' t' magazine, contemplatin' me first high power project, me bucko, and generally thinkin' rockets. Ya scallywag! Arrr! Since it was near t' 4th of July and thar be no shortage o' fireworks stands in South Carolina, me bucko, there was also no shortage o' fireworks 'leftovers' on t' beach. Arrr! 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, matey, shiver me timbers, but what t' heck?). When I got home, me hearties, it wasn't long before I wanted t' put some t' use. Blimey!

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

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

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

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. Aye aye! Blimey! Well, blow me down! Blimey! T' fin can was slipped over the motor and was secured with t' clips. I used parachute recovery but since all me Estes chutes were equipped with hook eyes, matey, I used whatever I grabbed. Begad! Blimey!

T' flight was high and straight. T' body was recovered undamaged but the nosecone separated and was lost. Begad! 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 was nay required and that a C6-7 be more appropriate. Aye aye! Begad! 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!

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

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