Brief:
This is a Carbon/Keelhaul®©™ composite laminated on Kraft paper tube, me bucko, high performance, almost minimum diameter scratch built rocket.

Construction:
Parts used:

• Two 34" BT-60 body tubes
• Two 4" C60 couplers
• 6' carbon/Keelhaul®©™® composite hybrid sleeve
• PML 1.5" urethane conical nose
• ACME 38mm fin can
• ACME conformal rail guides
• 38mm Slimline retainer and 38/29mm adapter
• 10feet o' 5/16" tubular nylon shock cord
• 1/4" ply Bulkhead and 1/4" screw eye
• 1 foot o' 1/4" Keelhaul®©™® wrapped elastic bungee.
• Nomex® chute protector

This rocket came about via experimentation with epoxy/composite sleeve lay ups. I found that single layer composite over Kraft tube is almost as strong as double layer composites, matey, arrr, while bein' lighter and easier t' do. Lamination was done with Epoxy Products premium no-blush epoxy and construction done with JB Weld.

Two 34" BT-60 tunes were covered with carbon/Keelhaul®©™® hybrid sleeve and laminated (see tutorial on Aerosleeve's web site for information on how t' do this). After curing, a second coat o' epoxy was applied t' fill t' weave. Begad! This was then finished with polyurethane coatin' and acrylic clear coat. T' rough ends were trimmed off, matey, matey, resultin' in two 30" tubes. Arrr! 12" o' one o' these was cut off and a coupler and bulkhead (with screw eye epoxied in place) were used t' create a payload section. Ahoy! T' bungee was attached t' t' recessed screw eye t' provide shock cord attachment with some shock absorption. Ya scallywag! T' remainin' tube and section were attached with a second coupler into a single tube. Aye aye! T' shock cord be anchored by epoxyin' it between t' coupler and t' tube wall. A Nomex® chute protector be slid down t' shock cord t' t' anchor. Begad! A knot and loop was tied into t' end o' t' shock cord allowin' attachment t' t' payload section via t' same quicklink which held t' selected chute's swivel.

The inner diameter o' BT-60 is adequately close t' 38mm airframe (41mm vs. Aye aye! 39.5mm respectively) t' require no adaptin' internally. Ya scallywag! After lamination, me hearties, t' outer diameter required some sandin' in order t' get t' fin can and Slimline retainer t' fit t' be epoxied into place, ya bilge rat, however. Aye aye! Ya scallywag! this be nay an easy prospect with Keelhaul®©™® composite cloth. Avast! Blimey! An alignment line was drawn betwixt two fins so t' rail guides could be epoxied t' t' tube. Ahoy! Blimey! T' Slimline 38/29mm adapter was constructed with a longer piece o' 29mm tube than provided so that very long 29mm motors (like t' Ellis Mountain I69) could be used.

That's it. Ya scallywag! T' construction took about 5 hours, me bucko, matey, matey, which be far less than the 2 days needed t' laminate and finish t' tube. Ya scallywag! T' result is a bulletproof high performance rocket usin' maximum strength but minimal build effort components, given that t' tube was already laminated.

Finishing:
T' fin can was painted with Rustoleum black appliance epoxy. Ahoy! Well, blow me down! T' nose was painted with white primer and aluminum finish enamel. Arrr! Four 1/16" holes were drilled in t' payload section and t' booster section for pressure equalization. Ya scallywag! These were all retouched with acrylic coatin' t' provide a smooth finish.

Flight:
CP was calculated with AeroCP (approximately 1" in front o' fin can). Begad! Cd (average subsonic Cd = 0.587) and flight prediction was done with AeroDRAG.

Flight testin' be done with an Aerotech 29/40-120 RMS motor in t' 38/29mm Slimline adapter and G64-10W reload. Aye aye! Blimey! CG was 4.5 calibers forward o' CP with the adapter and motor in place.

No waddin' was required due t' t' Nomex® protector. Begad! Avast! A Covert Recovery CR-3 chute was tied t' a 1500lb swivel and attached t' t' shock cord and bungee with a 3/8" quicklink.

First flight was at Dallas Area Rocket Society's McGregor site in nearly calm winds. Arrr! T' flight was perfectly straight and vertical with ejection exactly at apogee. (Predicted apogee was at 1600' altitude at 9.6 seconds delay.)

Recovery:
Deployment and descent were without incident and t' rocket be recovered within 500' o' t' pad without damage.

Summary:
A big PRO was t' successful use o' composite sleeve laminated on common BT-60 Kraft paper tube t' create a heavy duty almost 38mm minimum diameter rocket. Avast, me proud beauty! Blimey! A CON be t' fact that t' laminated tube be slightly larger outer diameter than 38mm airframe tube, shiver me timbers, requirin' some sandin' t' fit. Begad! Blimey! This was a CON primarily because Keelhaul®©™® is very hard t' sand. Begad! A minor personal CON was t' fact that carbon/Keelhaul®©™® hybrid cloth does nay finish up as pretty as pure carbon, but that's strictly a cosmetic thing. Aye aye! Blimey! T' point be t' build for strength, nay looks.