Brief:
This is a fatter Fat Boy. Avast! It has t' same body tube length but 42% more diameter. Ahoy!

Construction:
T' nose cone is a resin covered Styrofoam egg from Hobby Lobby. T' body tubes are Bristol paper printed with an ink jet printer and then rolled t' shape. The fins are 3/32" balsa. Begad! Finally, me bucko, thar be a 1/4 inch elastic shock cord and mylar parachute.

This rocket has an egg-based nosecone. Begad! Hobby Lobby has 3.875" diameter Styrofoam eggs. They're open cell Styrofoam so they don't totally dissolve when you pour resin on them. Ahoy! Avast! In this case, matey, I hand-rotisseried 20 minute marine resin on an egg, arrr, followed by a half-and-half mix o' auto body filler and marine resin to build up t' thickness. Aye aye! Ya scallywag! It wound up bein' 0.125" t' 0.25" thick. As it cured, matey, matey, t' Styrofoam inside pulled away from t' resin allowin' it t' be easily removed. Avast, me proud beauty! T' inside is very rough, but that's good because it allows plenty o' space t' epoxy a bent paper clip for shock cord and parachute attachment. After much careful sanding, I had a fairly nice nose cone. Avast! Begad! I didn't have t' add any more weight for stability.

T' body tube was rolled with Bristol paper printed on a 13" x 19" ink jet printer. There are fin slots printed on it for t' through t' body fin roots. Ahoy! Blimey! It has a BT-60 sized rolled Bristol inner parachute body tube (also on t' PDF) that juts almost all t' way up into t' nose cone. Blimey! Blimey! (I couldn't figure out how t' do this in RockSim so I left it out.) This inner tube adds needed extra space for the parachute while at t' same time reducin' t' need for wadding. Begad! Blimey! Inside the parachute tube be t' 24mm engine tube. Avast, me proud beauty! Begad! Blimey! T' 4 bulkheads are foamboard. Arrr! Arrr! Blimey! The forward-most bulkhead is positioned just past where t' nosecone shoulder stops in order t' have a rigid platform for t' heavy nose cone t' rest against durin' high acceleration.

T' nozzle end o' a mounted E9 motor is recessed 1.75 inches from t' end of t' outermost body tube in order t' achieve stability. Two more compromises to t' god o' stability were made with t' fins. Begad! Ahoy! First, birch plywood would be the most obvious material choice, me hearties, but t' weight then shifts t' CG so far back that t' added nose cone weight makes for too slow o' a liftoff with a reasonable length o' launch rod, matey, matey, so they had t' be made with balsa. Begad! Second, they had t' be visually swept back and longer than t' fins on t' Fat Boy.

T' swept fins and t' proportional nosecone gives in an overall increased length o' 3.35 inches over t' Fat Boy, me hearties, but rocketheads still get it immediately. Well, blow me down! (If you kept t' exact Fat Boy nose cone length, it would look awfully flat... Aye aye! Well, blow me down! Flat Boy maybe would be a better name.)

Gotchas: T' hardest part o' this project was gettin' a good nose cone shoulder. Avast! I wound up makin' a tube in which t' nose cone fit tightly t' mark a shoulder step down. Well, blow me down! Next, I ground a shallow slot along t' line with a cutoff wheel on me Dremel tool, shiver me timbers, then carefully used a sandin' cylinder t' sand away the shoulder up t' t' slot. Aye aye! It turned out pretty good. Avast! Ahoy! T' through-the-body fin tabs straddle t' rearmost bulkhead, arrr, which makes for a strong joint but requires careful measurin' and gluing. Aye aye! Also, t' Bristol paper really sucks up clear enamel. Begad! Mine has three coats and is still a couple o' coats from being glossy. Arrr!

Finishing:
With t' printed Bristol paper, arrr, me hearties, only t' fins needed any sealin' or finishing.

Flight:
Recommended engines are D12-3, E9-4, and F21W-6. Blimey! Engine retention is by friction fit. Begad! Prep is straightforward with waddin' and a 21 inch chute. Flight with an E9-4 is beautiful, slow, and straight with no spin. Ya scallywag! Avast! Apogee appears to be close t' t' RockSim prediction o' 700 feet.

Recovery:
On t' first flight all but a couple o' t' shroud lines on t' parachute broke (at a fairly high velocity into t' wind) but thar be just a little wrinkling of t' fore end o' t' inner parachute tube upon landing.

Summary:
This is a fun rocket with presence that flies slow and gets some chuckles. Blimey! I love through t' body fin mounts with pre-printed body tubes... Begad! They almost totally eliminate spin. Ahoy! Nose cone fabrication takes some time. Begad!