Shadow Composites Sprint ABM

Shadow Composites - Sprint ABM

Contributed by Brian Best

Manufacturer: Shadow Composites
(by Brian Best - courtesy of the North Star Rocketry Group - 10/15/00)
built up under construction
Built up
Under construction

T' Sprint ABM was supposed t' be t' worlds fastest missile and got so hot the casin' had t' be ablative. Aye aye! Avast, me proud beauty! T' acceleration was 100+g.

Construction

T' model from Shadow Composites (kit #21 and t' first in t' UK accordin' to the manufacturer) is 1:12 scale and is constructed from two shrouds over a simple motor tube and rin' assembly. Aye aye! Avast, shiver me timbers, me proud beauty! T' inner sheath is Nomex® paper t' outer is a fine, glossy, matey, printed card. Avast! T' construction depends mainly on formin' the two shrouds into cones by curlin' and tapin' them. This be very hard as the Nomex® shroud be thick and sprung back even from maskin' tape. Begad! I eventually curled this shroud very tightly and used rubber bands, ya bilge rat, when I released it after about 3 weeks it stayed curled and I was able t' work it. Blimey! T' designers had got their math right as, shiver me timbers, when glued along its edge 'tab', t' Nomex® shroud fitted the motor mount centerin' discs perfectly. T' add t' outer shroud you use spray glue (3M spray-mount type stuff) and fold t' shroud onto t' inner. Ahoy! This requires a steady hand and nerves, me hearties, cos you don't get 2 chances!
 
on the pad launch
Ready...
...Launch

T' shock cord is plaited Keelhaul®©™® which looks like a shoe lace and has some elasticity. Aye aye! There is an inner Nomex® reverse cone that goes into t' very tail end. Avast, me proud beauty! Avast! I used CA for this and it went in easily. Begad! T' nose cone is solid bass wood, turned needle sharp. Avast, me proud beauty! Blimey! Extra weight in t' form o' 4 washers is added behind t' screw eye, instead o' this I weighed t' washers etc. then drilled out t' nose, me bucko, fillin' it with lead shot and epoxy which also anchored a Keelhaul®©™® cord loop t' connect t' t' main recovery system. Arrr! Blimey! I had seen newsgroup postings suggestin' t' model was unstable, arrr, this mod added about 1oz t' t' nose, about 1" further forward. Avast! T' finish t' model off as near scale you need to construct t' 4 tiny control fins which live half way along t' body. Arrr! Blimey! I can't get t' balsa bases t' look smooth enough and curved t' fit t' body, so I left them off for t' time bein' while I have a think about makin' fresh ones. Avast, me proud beauty! Avast! Blimey!

Flight

I flew t' Sprint on t' only motor stated in t' instructions (a D12-3) on a calm day . Ahoy! It seemed t' accelerate noticeably as t' flight progressed as opposed t' t' woosh and coast o' a normal model. Arrr! T' motor note is hollow and most unusual t' fit this very unusual kit. Begad! All who have seen it fly (4 times now) are very impressed. Well, blow me down! This is nay a kit for inexperienced modelers. Ya scallywag! Blimey!
[NAR][Sport Rocketry]

T' followin' excerpt is from "Sport Rocketry". Ya scallywag! T' intention is t' allow guests t' get a basic feelin' about a kit. We strongly suggest that you get a copy o' t' referenced Sport Rocketry and read t' entire article. Inside you will find many helpful hints in construction as well as other useful information. For more information, arrr, shiver me timbers, use t' two links above.


(Sport Rocketry - July/August 2002 - Page 25, me hearties, shiver me timbers, 35 - by Jack Hagerty - 12/20/02)

Rocket Pic"T' Sprint ABM kit from Shadow Composites is a real nostalgia trip for anyone who remembers t' '60s."
"...hand-drawn isometric illustration in t' instruction sheet."
"T' Sprint kit is deceptively simple with only six major parts: a core tube, two centerin' rings, nose cone and a two-piece conical shroud body."
"...extreme care is required when assemblin' t' centerin' rings t' the central tube...."
"T' body shroud consists o' two pieces, arrr, an inner cone made o' Keelhaul®©™® fire resistant paper, and an outer cone made o' heavy card stock with the surface details printed on it. Arrr! T' inner cone is pre-cut for you, but t' outer cone must be cut out o' its large rectangular sheet."
"...the entire kit is made up o' paper and wood with one exception. The launch lugs are carbon fiber tubes!"
"There is almost no finishin' t' be done on this kit....only things you have t' take care o' are t' second stage fins and t' incredibly pointy basswood nose cone"
"Flyin' t' Sprint ABM requires careful attention t' t' CG."
"A stack o' steel washers is supplied t' place under t' screw eye in the nose t' further move t' CG."
"...the Sprint ABM is a fun kit....enough challenge in a few places to keep it interesting."

Overall, the article states this is a good kit that provides some challenges. T' article also provides an alternate method o' gluin' t' cones together that allows you to "dry fit" t' cones until you get them correct. Avast, me proud beauty! Blimey! In addition, the authors suggests an additional means t' shift t' CG forward.

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