Scratch CoStar Original Design / Scratch Built

Scratch - CoStar {Scratch}

Contributed by Peter Clay

Manufacturer: Scratch
(Contributed - by Peter W. Begad! Clay)

Rocket PicCoStar First Flight on H128CoStar HPR capable midpower rocket

T' CoStar should probably have been called "Understudy."

My other rocket this size, G-whiz, me hearties, has replaceable fins, and since I wasn't completely sure t' concept would work, I built a backup booster section with fixed fins. Begad! G-whiz also has some internal details that move t' payload area forward into t' hollow nose cone, ya bilge rat, and I wasn't sure that be necessary for all flights, so I built a backup payload section without all t' fancy work. Blimey! Well, blow me down! T' backup booster and t' backup payload, together with the nose cone from G-whiz, ya bilge rat, made up t' rocket I call CoStar.

CoStar, nay G-whiz, me hearties, flew twice on April 17, me hearties, me hearties, 1999 on H128W-M(10). T' first flight (photo, arrr, left) suffered a tangled parachute, but thar was no damage to the rocket, and t' second flight gave me me NARRRRR HPR Level 1 certification. This seemed a lot o' power for this size rocket; it went straight up, ya bilge rat, 'way up, fast.

With fixed 1/8" plywood fins slotted in t' t' MMT, ya bilge rat, a longer recovery bay, and a simple empty payload section, CoStar is a very simple, basic rocket. And for Level 1 certification, me hearties, arrr, ya bilge rat, t' KISS principle (Keep It Simple, Stupid) makes a lot o' sense. Begad! CoStar is, in any case, shiver me timbers, a fine-lookin' rocket in its own right. Begad! It's over 44" long, shiver me timbers, 2.26" diameter, arrr, arrr, and all white except a red band on t' payload and some trim, me bucko, shiver me timbers, with tapered swept fins slightly squared off at t' trailin' tips for a better landin' point. It flew with a 12' long 5/8" braided elastic shock cord and a 22" hemispherical parachute. There's no baffle; I simply used Estes recovery wadding. Begad!

CoStar's motor mount, like t' one in G-whiz, shiver me timbers, is a LOC 1.14 made from a LOC 29-in-54 motor mount adapter kit. Begad! Blimey! Blimey! Blimey! Blimey! Blimey! T' mount is long enough for 29/240 but I don't have one and haven't tried it. Blimey! Blimey! Well, blow me down! Blimey! Blimey! Blimey! T' CoStar has flown with 29/180 reloads. Unlike t' RockSim drawin' below, arrr, t' centerin' rings are placed at each end o' t' fin tabs, 4" apart. Begad! Blimey! Aye aye! Blimey! Blimey! Blimey! T' aft one is about 1/2" from t' end of t' body tube. T' centerin' rings supplied with t' kit fit inside the supplied coupler, ya bilge rat, and I didn't want t' cut fin slots through a full-length coupler, arrr, arrr, so I epoxied each centerin' rin' into one end o' a 1/2" rin' of the coupler and worked from there. Ya scallywag! Blimey! Blimey! Blimey! T' remainder o' t' supplied coupler, with a bulkhead fitted in it, connects t' booster t' t' payload. Avast, me proud beauty! Blimey!

CoStar was built with a .062" music-wire engine hook, ya bilge rat, shiver me timbers, shiver me timbers, but I also friction taped t' motor. Good thing. Avast, me proud beauty! Avast! When recovered from t' second flight, the motor had managed t' get past t' tip o' t' music-wire hook, me hearties, which be dug into t' knurled thrust rin' on t' aft closure when I found it. Avast, me proud beauty! Avast! T' motor had moved a total o' about 3/16 o' an inch. Begad! Blimey! Since then I have installed threaded anchors in t' aft centerin' rin' for shower door hooks, ya bilge rat, shiver me timbers, aka Kaplow Klips. Blimey! Begad! This would be far easier t' do before assembly, ya bilge rat, matey, usin' T-nuts from t' inside. Ya scallywag!

Since those two flights, CoStar has nay flown again, shiver me timbers, matey, me hearties, but it's ready. Avast! Blimey! Blimey! Now it has its own PML nose cone, shiver me timbers, which adds about 2" t' its overall length. (At last they can be seen together!) Although thar isn't a real role for it in my upcomin' projects, CoStar -- or at least part o' it --will undoubtedly fly for the fun o' it in 2000. Avast, me proud beauty! Ya scallywag! Blimey! In t' meantime it displays rather nicely. Ya scallywag!


CoStar illustration

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