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

Construction:
3 2.6" airframe sections 18", ya bilge rat, 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, shiver me timbers, 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. Aye aye! Blimey! 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, put them together and stuck them TTW to t' MMT. Begad! Blimey! Ahoy! Blimey! I CA'd t' G-10 parts on and removed t' plywood fin. Well, blow me down! Blimey! Repeat 2 more times, matey, shiver me timbers, and apply inside and outside fillets with 30 min epoxy. Now I have 1/8" slots for t' fins t' go in betwixt t' G-10 mountin' points. Well, blow me down! Blimey! Begad! Blimey! After the epoxy was dry I inserted t' fins and drilled 1/4" holes for t' screw posts, ya bilge rat, through t' G-10 and fins at t' same time. Aye aye! Blimey! These are what hold the removeable fins onto t' airframe. Ya scallywag! Blimey! This is a very sturdy rocket that I glassed with 4oz fiberglass. 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. Begad! I used standard cellulose waddin' and 20' of Keelhaul®©™® for shockcord. 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. Blimey! T' F-52 is a little better, shiver me timbers, and it flies great on a G-64-7. Aye aye! Avast! T' 28" chute brought it down softly from about 700'. Well, blow me down! Ya scallywag! Flight rating....5

Summary:
Pro's...... Blimey! You can replace broken fins, me bucko, or just redesign it whenever you want. I like t' test different material types......Lexan, matey, G-10, plywood etc. Con's.....None

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