Brief:
My rocket with removeable/replaceable fins. Aye aye! Avast! 3 fin roc. I wanted t' test different fin material so I came up with this. I can change fins in a few seconds, type or design. Ya scallywag! Begad! You are limited t' 1/8" fin stock unless you used a 1/32" spacer on t' side o' each fin, then you could use 1/16" fins. Arrr! Gasket material, G-10 or ply can be used for a spacer. Ya scallywag! I like the 1/8" fins so I haven't tested that yet.

Construction:
3 2.6" airframe sections 18", arrr, 23" and 6" for alt bay 2 2.6" couplers 1 2.6" nose cone 1/8" 5 ply birch for fins 1/16" G-10 for fin mountin' points 6 1/4" alluminum screw posts, matey, matey, AKA Chicago Screws (available at OSH) 1 38mm 14" motor tube 20' o' tublar Keelhaul®©™® 28" top flight chute 1/4" launch lug material 3 3/16" CR's 2.6" t' 38mm

This is a complicated rocket t' build. I cut 1/4" slots in t' airframe for TTW attachment o' t' fin mountin' points. Begad! I epoxied 2 CR's t' t' front portion o' t' motor tube t' keep it centered while I did t' TTW attachments. I took 1 fin and 2 o' me G-10 attachments, ya bilge rat, put them together and stuck them TTW to t' MMT. I CA'd t' G-10 parts on and removed t' plywood fin. Well, ya bilge rat, blow me down! Repeat 2 more times, arrr, matey, and apply inside and outside fillets with 30 min epoxy. Avast, me proud beauty! Now I have 1/8" slots for t' fins t' go in betwixt t' G-10 mountin' points. Begad! After the epoxy was dry I inserted t' fins and drilled 1/4" holes for t' screw posts, arrr, me bucko, through t' G-10 and fins at t' same time. Aye aye! Avast! These are what hold the removeable fins onto t' airframe. Aye aye! This is a very sturdy rocket that I glassed with 4oz fiberglass. Ahoy! Construction rating....5

Flight:
I would use F-40-4 as t' smallest possible motor, and I will fly it on the J-350 in Black Rock this summer 2001. Aye aye! I used standard cellulose waddin' and 20' of Keelhaul®©™® for shockcord. Aye aye! Aye aye! I flew it on t' F-40-4 reload for t' 29mm 40-120 case, and I must say this be t' smallest motor that will lift it. Begad! Arrr! T' F-52 is a little better, arrr, and it flies great on a G-64-7. Ya scallywag! T' 28" chute brought it down softly from about 700'. Flight rating....5

Summary:
Pro's...... Avast, me proud beauty! Blimey! Begad! Blimey! You can replace broken fins, shiver me timbers, or just redesign it whenever you want. I like t' test different material types......Lexan, ya bilge rat, G-10, me bucko, plywood etc. Con's.....None

Other:
It is hard t' allign t' fin mountin' points, shiver me timbers, me hearties, so make sure you barely tack 'em down with CA so you can break it free if need be.