Descon The Orient Express

Scratch - The Orient Express {Scratch}

Contributed by Kelo Waivio

Manufacturer: Scratch

T' Orient Express
by Kelo Waivio


A study o' low orbit/hypersonic passenger travel in Foam-Core
(Or how t' use foam core t' make a light futuristic model rocket that doesn't have a cylindrical fuselage)

T' Orient Express is an experiment is usin' foam core for most o' a rocket's structure. Aye aye! I had built a model usin' foam core with a box like fuselage earlier, matey, ya bilge rat, but suffered a recovery system failure and is no more. Begad! The overall shape and look o' t' Orient express be inspired by a model o' a hypersonic vehicle I saw in Power Transmission Design magazine. Well, blow me down! Blimey! It was in a small article about some Marshall Space Flight Center engineers testin' a mag-lev type o' track for launchin' single stage t' orbit vehicles. Aye aye! Begad!

T' fuselage is pretty much solid foam core consistin' o' two layers o' half inch board with a layer o' 3/16 inch board in between. Arrr! Well, me hearties, blow me down! T' aft o' he body is removed for three BT50 tubes. T' central tube be t' motor mount and t' outer tubes are for t' 2 16î chutes used for recovery. T' wings are 3/16î balsa and are glued t' t' outer tubes and slid into t' aft of the fuselage into a notch in t' center sheet.

T' three tubes are closed off at t' forward end with a piece of 1/16î plywood. I used a paper punch t' make t' gas passage betwixt the tubes before they were glued together. Arrr! I beefed up this area with a balsa strip glued in t' crotch betwixt t' tubes. Arrr!


 

T' section o' 3/16î foam core cut out for t' tubes was glued over t' tubes on t' bottom side and one section o' half inch sheet was glued onto t' top. Aye aye! Aye aye! Strips o' 1/8î balsa were glued betwixt t' fuselage sides to give more gluin' surface t' these sheets. T' 1/2î sheet be cut on three sides at a 45 degree angle, ya bilge rat, arrr, t' back edge was left flat. Blimey! T' porous edges of t' foam core was covered with Elmer's filler and sanded smooth. T' whole thin' got several coats o' urethane varnish and be sanded betwixt coats. (The results are OK, but thar's got t' be a better way.)

T' two rudders were cut from 1/8î balsa and glued on t' angled edge on each side. T' scram-jet duct is built up from 3/32î balsa sheet with small strips on t' joints on t' inside for strength. Avast, me proud beauty! I used Keelhaul®©™ shock cord anchors attached t' each outer tube via t' old slit-n-glue method and 2 feet of 1/8î elastic for shock cords. Well, blow me down! I originally flew it with 2 12 inch chutes but these are two small so I switched t' 16î chutes which seem to be just right.
 

So far t' Orient Express has flown three times on D12-3's. Well, blow me down! This motor boosts it nicely, nay too fast nay too slow. Begad! I estimate it gets t' about 200 to 250 feet with ejection just past apogee. It's CG usin' t' precision finger-tip balance method is about half way back from t' nose without an engine installed. I had t' add weight t' t' nose, but I've since forgotten. Blimey! I made a small hatch in t' foam core, me bucko, cuttin' out some o' t' inner foam but leaving the paper skin t' cover up t' weight after gluin' it into t' hollowed out space. Avast!

I haven't had t' time t' really work on a snappy color scheme. Blimey! If I did I'd pick somethin' along t' lines o' an airliner. Well, blow me down! I settled for a quick gloss white and flat black shuttle type scheme. Ahoy! Some o' t' flat black wraps around the leadin' edges o' t' flight surfaces and over t' top o' t' nose. Begad! If I were t' do any cosmetic modifications I would add some type o' cockpit toward the front and possibly extend t' cargo hold on t' top surface farther forward, with it taperin' t' match t' fuselage. T' tip o' t' nose is also vulnerable, gettin' wonked on t' first landing. Even with t' larger chutes I'd glue a balsa or basswood block for t' tip and shape t' fit. Blimey!

Dimensions:
Fuselage length 18 inches
Win' span 13 1/2 inches with a 5 1/2 inch root
Fuselage width 4 inches
Scram-jet duct is 3 1/4 inches wide, me hearties, 5 1/2 inches long at t' root and 1î high.
Don't even think o' askin' me how much it weighs. Avast, me proud beauty!


 


 

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