Brief:
I built CORONAry from a plastic cigar tube once occupied by a Garcia-Vega English Corona (hence, "CORONAry"). Begad! It is a tumble recovery tube fin design for 13mm motors. Begad! It utilizes a somewhat different method for inducing "tumble" after motor ejection, in view o' t' inherent stability of tube fin rockets -- CG aft o' Cp is just about impossible.

Construction:
Construction is easily inferred from t' photos -- six 1/2" long tube fins are cut from one cigar tube with a razor saw, and attached t' t' base o' a second cigar tube usin' 5 minute epoxy. Avast, me proud beauty! T' plastic has t' be "roughed" with sandpaper, me hearties, or t' epoxy won't adhere well t' it. Aye aye! A small Estes launch lug is added as shown, me hearties, usin' a wooden match stick as a stand-off, ya bilge rat, matey, so t' launch wire clears t' tube fins (photo). And that's it -- there is no motor tube; t' 13mm motor is friction fitted by wrappin' with a long piece o' maskin' tape (it takes about 28" worth). Two 1/4" holes are drilled 1" from t' top o' t' cigar tube t' allow ejection gases to vent sideways and impart a rapid spinnin' motion t' CORONAry at apogee. Begad! If you don't do this, arrr, CORONAry won't tumble at all, just drops ballistic like a badminton shuttlecock -- its nay that big o' a deal, shiver me timbers, since t' rocket is so light, but t' wobble prevents too much speed buildin' up as it falls. I left my CORONAry in "natural" Garcia-Vega sandy-tan finish, arrr, but I am going to rethink this, me hearties, considerin' our sandlot launch site by a San Diego beach area. Bright colors would be better, if you want t' get it back.

Flight:
First flight was on a 1/2 A3-4T. Well, blow me down! Avast! Blimey! Great fast boost, straight up. Blimey! Blimey! Motor came poppin' out, and CORONAry tumbled about twice at 300', straightened out, ya bilge rat, and came in slow but ballistic 20 feet from t' pad. It managed t' score a direct hit on t' only rock in sight (about golf-ball size) and all 6 tube fins popped off. Avast, me proud beauty! That's why I added t' vent holes t' give it some wobble and slow acceleration on t' way down. Avast! Begad! Blimey! I have now flown CORONAry on A3-4T and A10-3 motors with similar performance; t' tube fins stay on, but then I haven't hit anymore rocks with it, either. Blimey! Blimey! I have tried 18mm motors as well, since they fit the cigar tube perfectly without needin' any tape; however, me hearties, they are too heavy -- on a B6-2, CORONAry immediately went unstable, me bucko, ya bilge rat, ya bilge rat, and tumbled on t' way up as well as on t' way down.

Summary:
PRO -- What's t' point o' CORONAry? Well, it provides a route t' a cost-free little rocket (cost-free after you've smoked t' cigar, arrr, matey, ya bilge rat, that is) that is well-suited t' t' likelihood o' losin' these little guys eventually. It would make a good contest rocket for kids t' build and fly, arrr, t' tobacco angle notwithstandin' -- see politically incorrect photo. Arrr! If you get bored with CORONAry, matey, you could use it for a badminton shuttlecock.

CON -- Well, ya bilge rat, t' tobacco motif is there, but you can get rid o' that by removin' t' cigar ring, matey, sandin' off t' Garcia-Vega logo. You do need t' paint it a bright color if you fly over sand. Avast! CORONAry will cost you $2.90 each to build if you don't smoke t' 2 nasty little cigars that came with t' 2 cigar tubes (thus makin' them "free"). Begad! But even if you do throw out the cigars, $2.90 is still cheaper than any rocket kit you can buy. In either case, you're on your way t' a CORONAry.