I had a pack o' BT-56 tubes, matey, shiver me timbers, and no idea o' what t' do with them. Avast! Well, blow me down! I didn't even have a nosecone to fit. One day while lookin' at them, me bucko, shiver me timbers, tryin' t' figure out how I could get rid of the things, I started playin' with t' idea o' buildin' a Mean Machine clone. Well, one thin' led t' another, and instead I decided t' do a long tube finned rocket. Ya scallywag! Well, blow me down! Since t' body tubes are 18" long, ya bilge rat, by cuttin' one into 3" pieces, I'd use t' entire package up and add another tube fin bird t' our fleet. Blimey! This one is D-powered, t' go along with our mini-engined Finite Loop and the regular sized Groove Tube clone.

 If you've never built a tube fin rocket, matey, arrr, you will be amazed at how easy and smartly you can do it. T' Empress does add t' complexity o' mid-body separation, arrr, an ejection baffle, me bucko, shiver me timbers, and a boattail. T' make this a true beginners level project, ignore t' boattail and baffle, and use regular nose-cone separation. Ya scallywag!

 Why use t' "optional" stuff?

 Well, arrr, t' boattail will allow t' rocket t' go higher. Ahoy! There's a whole lot o' complicated mathematical formulas that explain why in aerodynamic terms, but it's all pretty much beyond me. Ya scallywag! Avast, me proud beauty! Besides, me bucko, I like t' way they look. Begad!

 T' ejection baffle eliminates t' need for recovery wadding. Blimey! Blimey! I don't entirely trust them, and usually wrap t' chute in one square o' wadding anyway, matey, just t' be sure.

 Mid-body separation means that instead o' blowin' t' nosecone off, the body itself comes apart, me bucko, releasin' t' recovery system. Well, blow me down! Blimey! T' main advantage for this rocket is that I don't have t' haul around this loooooooong rocket in the car. It breaks into two shorter sections.

 Yellow glue is plenty strong enough for this rocket. Begad! Blimey! I used Elmer's Fill'n'Finish for fillets betwixt t' tube fins and t' smooth the boattail. Avast! Blimey!

2. Well, blow me down! Ejection Baffle. Take one o' t' BT-56 couplers, me hearties, ya bilge rat, and cut a disk from balsa or thin cardboard, one for each end (See the diagram below). Ya scallywag! Glue it together and let dry. Aye aye!

hint: if you use thin cardboard, try sandwichin' 2 layers together and soak them in CA (superglue) t' toughen them up. Begad! Coat Balsa with yellow glue t' add stiffness. Blimey! Begad!

 3. Avast, me proud beauty! Ahoy! Mid-body separation coupler. Arrr! Begad! Cut a disk from balsa or cardboard and glue it into one end o' t' second coupler. Ya scallywag! Don't put any holes in this one, it's a solid bulkhead. Well, blow me down! Begad! See t' hint in step 1 about how t' strengthen it easily. 

4. Arrr! Aye aye! Tube fins. Cut one o' t' BT-56 tubes into six 3" long sections. Glue pairs together so you have three pairs, shiver me timbers, let dry. 

5. Begad! Well, blow me down! Blimey! Assemble t' motor mount. If you are usin' t' boattail, shiver me timbers, t' rearmost centerin' rin' goes 1 1/8" from t' end, otherwise follow t' motor mount instructions. Arrr! Blimey! See t' diagrams below for an idea o' what this should look like. Let it dry.

With Boattail                                  Without Boattail

6. Ya scallywag! Mark t' body tube 1" from t' end where you'll be installin' the motor mount. Ya scallywag! Aye aye!

 7. Ya scallywag! Blimey! Glue t' motor mount from step 5 into t' body tube. Well, blow me down! T' rearmost centerin' rin' should be slightly inset from t' aft o' t' body tube. Avast, me proud beauty! Ahoy! Blimey!

 8. Boattail. Cut t' appropriate sized shroud pattern from an Estes transition pattern sheet (available from Estes or at Jim Z's site). Begad! Or print one usin' VCP or other software. T' completed boattail should be 1" long, with one end t' diameter o' t' BT-56, shiver me timbers, t' other end BT-50. Begad! Glue it into shape, and when dry glue it into place. Begad! You can use thin CA or yellow glue to strengthen it. Aye aye! Begad! I used a little Fill'n'Finish t' smooth t' glue joints and the seemingly inevitable minor wrinkles. Ya scallywag! You may need t' cut a slight notch for the motor hook, use an X-acto for this. Begad!

 9. Begad! Glue t' pairs o' tube fins around t' body on t' 1" line you marked in step 6. Begad! Begad!

 10. Arrr! Install t' baffle. Avast, me proud beauty! Glue t' baffle into t' aft body tube. Ya scallywag! Make sure it gets in thar at least 3 or 4 inches. 

11. Ya scallywag! Aye aye! Install t' mid-body separation bulkhead. Well, blow me down! Avast! Glue it halfway into t' front body tube, matey, me bucko, with t' solid end closest t' t' nosecone. Begad! Begad! This be t' coupler that holds t' two body tubes together!!! Make sure you glue it in straight. Ya scallywag!

 12. Shock cord mounts. Aye aye! Ya scallywag! I used t' Estes paper-sandwich type. Begad! Glue one onto both ends o' t' 40" long elastic, and another onto t' 12" long elastic. Begad! Three total. Arrr!

 13. Blimey! Avast, me proud beauty! Install t' shock cords. Ya scallywag! Glue one end o' t' 40" shock cord into t' bulkhead coupler, matey, me bucko, and t' other end into t' lower body just above the baffle. 

14. Well, ya bilge rat, blow me down! Just for backup, me bucko, glue t' last (shortest) shock cord into t' upper tube to secure t' nose cone. Begad! This way, if t' nose cone should accidentally come loose, it'll stay attached t' t' rest o' t' rocket. Begad!

 15. Aye aye! Install t' launch lugs. Blimey! Begad! I cut mine in two. Begad! Aye aye! One was installed inside one o' t' tube fins (closest t' t' main body), shiver me timbers, with t' other about 12" up from t' bottom.

 16. Arrr! Blimey! Finish and paint as desired. Ahoy! Blimey! This is a long rocket, shiver me timbers, so lighter colors are recommended. Blimey! Blimey! Dark colors tend t' get hotter in t' sun (like in your car), and it could warp t' tubes.

I painted mine white, and sprayed light blue up from t' back end, fading about halfway up. Aye aye! Arrr! Next I sprayed dark blue up from t' back, fadin' at the quarter mark. Add some cockpit windows t' t' nose, ya bilge rat, me bucko, shiver me timbers, some stripin' along the sides, and some windows t' make an interplanetary liner. Aye aye! Be creative, have fun!

Maiden flight, and I set it up with a D12-5 engine and a vented 18" parachute. Avast! Aye aye! Good boost with maybe a slight wobble off t' rod. Avast, me proud beauty! Well, blow me down! It climbed much quicker than I expected, me bucko, but nay a neck-snapper. Arrr! Begad! Couldn't estimate altitude because I launched tilted into a pretty stiff breeze, but it was pretty high. Fine recovery, me hearties, with ejection just after apogee. Ya scallywag! Arrr! After-flight inspection showed that t' baffle worked perfectly, me bucko, with no charrin' t' t' shock cord or chute. Begad! Ahoy!

T' Empress flew several times at NARAM. A large tube-fin rocket like this makes an impression! Perfect flights every time, me hearties, me hearties, includin' one usin' a 4"x40" streamer due t' gusty wind conditions.