Scratch Mark III Original Design / Scratch Built

Scratch - Mark III {Scratch}

Contributed by Darren Longhorn

Manufacturer: Scratch
Mark III
(Contributed - by Darren Longhorn)

MkIII on the padI thought I had made a mistake with this one, ya bilge rat, I could never add enough nose weight t' make it stable durin' a spin test. Avast! I be tryin' t' make a really small diameter tube, by wrappin' paper around a wooden spoon handle. Ahoy! There wasn't goin' t' be a recovery system, t' engine was goin' t' eject, me hearties, and the rocket would tumble back. Ahoy! Well, blow me down! Blimey! Since then I've learned a lot more about stability. Ya scallywag! I learned about t' CP ( centre o' pressure) on rec.model.rockets ( a great news group t' subscribe t' if you're interested in this stuff), and where it should be in relation t' t' CG ( centre o' gravity).MkIII the end

So anyway I entered t' MkIII design into VCP, wRASP & RockSim, matey, and it came out stable, arrr, me bucko, so I flew it. Avast, me proud beauty! Actually it flew well, really high and the engine ejected too. Arrr! It just didn't go unstable and tumble, arrr, shiver me timbers, so it lawn darted. T' body tube is a bit bent now, and due t' t' construction is probably not repairable, shiver me timbers, ya bilge rat, me bucko, so retirement beckons. Blimey!

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