Brief:
I built CORONAry from a plastic cigar tube once occupied by a Garcia-Vega English Corona (hence, me hearties, "CORONAry"). It is a tumble recovery tube fin design for 13mm motors. Avast, me proud beauty! 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, matey, and attached t' t' base o' a second cigar tube usin' 5 minute epoxy. T' plastic has t' be "roughed" with sandpaper, or t' epoxy won't adhere well t' it. Well, blow me down! A small Estes launch lug is added as shown, usin' a wooden match stick as a stand-off, so t' launch wire clears t' tube fins (photo). Well, blow me down! 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). Ya scallywag! 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. If you don't do this, me bucko, CORONAry won't tumble at all, shiver me timbers, just drops ballistic like a badminton shuttlecock -- its nay that big o' a deal, matey, arrr, 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, ya bilge rat, but I am going to rethink this, arrr, considerin' our sandlot launch site by a San Diego beach area. Bright colors would be better, me bucko, if you want t' get it back.

Flight:
First flight be on a 1/2 A3-4T. Arrr! Begad! Great fast boost, straight up. Begad! Begad! Motor came poppin' out, me hearties, arrr, 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. Aye aye! That's why I added t' vent holes t' give it some wobble and slow acceleration on t' way down. Aye aye! I have now flown CORONAry on A3-4T and A10-3 motors with similar performance; t' tube fins stay on, ya bilge rat, but then I haven't hit anymore rocks with it, ya bilge rat, either. Arrr! I have tried 18mm motors as well, matey, matey, since they fit the cigar tube perfectly without needin' any tape; however, ya bilge rat, they are too heavy -- on a B6-2, arrr, CORONAry immediately went unstable, and tumbled on t' way up as well as on t' way down. Begad!

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, me bucko, shiver me timbers, 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, shiver me timbers, t' tobacco angle notwithstandin' -- see politically incorrect photo. Avast! If you get bored with CORONAry, you could use it for a badminton shuttlecock.

CON -- Well, t' tobacco motif is there, but you can get rid o' that by removin' t' cigar ring, sandin' off t' Garcia-Vega logo. Begad! You do need t' paint it a bright color if you fly over sand. 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"). Aye aye! Begad! But even if you do throw out the cigars, me bucko, $2.90 is still cheaper than any rocket kit you can buy. Begad! In either case, you're on your way t' a CORONAry.