Scratch Mark II Original Design / Scratch Built

Scratch - Mark II {Scratch}

Contributed by Darren Longhorn

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

MkII on padT' body was made from an aluminium foil core, matey, a tube approximately 25mm in diameter and 300mm long. Begad! It had balsa fins, ya bilge rat, right angled triangles about 50mm long on the opposite and adjacent sides. Aye aye! T' fins passed through t' body tube and formed spacers onto which t' engine mount would fit. T' engine mount be made from floppy disk labels again, matey, shiver me timbers, with 1mm solid copper wire as t' engine restraint & retainer.

T' best thin' about this rocket was t' nose cone, which be turned from balsa on a lathe, matey, by local school teacher Brian Thompson, thanks again Brian. Attached t' t' nose cone be a peizo -electric buzzer, t' help locate the rocket after recovery. T' ensure safe recovery I bought an Estes parachute, I've never had much luck with streamers. Begad! Avast! Blimey!

I flew t' MkII about a dozen times on various B & C size Estes engines, and had some success. Begad! Aye aye! I did have one recurrin' problem though which be that the shock cord would break after 2 or 3 flights. Avast, me proud beauty! What normally happened was that t' nose cone would become detached, ya bilge rat, and t' main body would recover normally, matey, although it would travel a long way if thar be ANY cross wind. Fortunately I could always find t' nose cone, matey, me hearties, because o' t' buzzer. However on t' last flight nay only did t' nose cone detach, I think t' parachute and body separated too. It was hard t' tell, shiver me timbers, but t' parachute blew away really quickly and didn't show any signs o' comin' down. Well, blow me down! Well, me hearties, blow me down! What happened t' t' body remains a mystery, we never did find it. Ya scallywag! Well, matey, blow me down!

MkII recoveryWell it was nearin' t' end of its life anyway as t' engine mount was becomin' very ragged, shiver me timbers, and thar was a real knack t' gettin' a new engine in. Arrr! T' engine mount be always a bit askew ( which meant it always went up at about 5° from t' vertical) and the trailin' edges o' t' fins were bein' burnt away. Avast!

comment Post a Comment