Scratch Deanston Marauder Original Design / Scratch Built

Scratch - Deanston Marauder {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
Style: Futuristic/Exotic

Brief:
(Scratch) Stubby Rocket with Foam FinsThis is a ducted, stubby, 24mm-powered rocket that sports replaceable foamcore fins. Well, blow me down! It flew nicely, me hearties, but recovery was less than optimal. T' name Deanston came from t' source o' t' larger tube--a bottle o' single malt scotch.

Construction:
T' rocket used a central BT-60 centered in a larger tube. Ahoy! Blimey! Well, blow me down! Blimey! Blimey! Blimey! T' larger tube was 3 11/16 OD and 10.375" long. Ya scallywag! Blimey! Blimey! Blimey! I found that t' difference betwixt t' BT-60's OD and t' outer tube's ID was exactly twice t' diameter o' BT-50 tubing, so t' BT-60 was centered usin' just that. There were three pieces o' BT-50 on t' base and another three near t' top. Avast, me proud beauty! Blimey! Blimey! Blimey! T' leadin' edge o' t' larger tube was outfitted with a short transition t' a smaller diameter tube and t' forward BT-50 tubes abutted that.

(Scratch) Stubby Rocket with Foam Fins(Scratch) Stubby Rocket with Foam Fins

(Scratch) Stubby Rocket with Foam Fins(Scratch) Stubby Rocket with Foam Fins

I be thinkin' that this would resemble some bulbous version o' a Mig jet fighter so I procured a ram-jet cone from Semroc.

I began playin' around with large fins in RockSim, ya bilge rat, both for stability and because t' outer body was so fat. For a long time, I had been thinkin' about buildin' a rocket that used replaceable foamboard fins, so that's how I proceeded. Ahoy! Blimey! Begad! Blimey! Blimey! Blimey! I built three plywood frames with t' dorsal frame bein' different from t' other two. Blimey! Blimey! Avast, me proud beauty! Blimey! Blimey! Blimey! T' attached photo shows some prototype fins installed. Well, shiver me timbers, blow me down! Blimey! Blimey! Blimey! T' fins were snug, ya bilge rat, but I added a nylon pop-rivet on each just t' be sure they stay in place. Begad! Blimey! Replacin' t' fins would involve removin' t' rivet and slidin' them out. Avast! Blimey! T' new fins would be slid into place and t' rivet reinserted.

I made a cockpit section from a chunk o' scrap tubin' and a clear plastic doohickey provided by Don Brown. Avast, me bucko, me proud beauty! Blimey! T' pilot was a piece o' a monkey-faced plastic skeleton. Arrr! Blimey! (Yeah, it be chopped up before I realized that it could be used as a paratrooper in me Boot Hill rocket.)

(Scratch) Stubby Rocket with Foam Fins T' white fins were smartly cut just as a concept and I had bought a piece o' black foamcore. Ya scallywag! Blimey! However, shiver me timbers, after several iterations in RockSim, I was convinced that they would make t' rocket stable and decided t' use them for t' maiden flight. Ahoy! Blimey! T' whole idea o' t' removable fins be t' allow multiple designs and nay t' worry about crunches.

Finishing:
T' inner body and most o' t' cone was painted with Painter's Touch red and t' body was painted with Rustoleum flat black. Ya scallywag! Blimey! I added a few skull-and-crossbones stickers t' complete t' pirate marauder theme.

 

Flight and Recovery:
I loaded up an E18-4 and an 18" nylon chute. Aye aye! Avast, me bucko, me proud beauty! T' boost was nice (see photo attached t' flight log) but t' delay was short. T' rocket flew into t' chute which stayed thar for t' duration o' t' flight. This resulted in a core sample. T' cone and replaceable fin frames survived and are bein' recycled.

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