Brief:
This is a transgalactic driftship employin' unique dual dark matter ramjets for high-speed travel t' t' edges o' t' charted universe. Blimey! Avast! T' ship carries a scientific crew o' up t' 74 humans. Its primary mission is exploration and astrobiologic sample collection. This is me first scratch rocket. Aye aye! It is a single stage, arrr, matey, minimum diameter futuristic tube fin rocket with parachute recovery. Arrr! Aye aye! It is designed for single use 24mm D and E engines. With an adaptor, it can fly on 18mm motors. Begad! Construction is fairly challenging, ya bilge rat, especially the cuttin' and joinin' o' t' elegantly curved tube fin assembly. Arrr! For a fair price, ya bilge rat, I can put together a kit with detailed instructions and photos. If you prefer, I can send only a parts list with t' instructions. Well, me hearties, blow me down! Email me for details. Begad! Below is a short description o' how construction proceeded.

Construction:
T' materials used are shown in t' first photo. Begad! T' rib fins are made from 1/16" basswood, shiver me timbers, and t' fin tube was a heavy-duty variety. Avast! These and my other parts were supplied from Aerospace Specialty Products. I be impressed by the quality o' t' products they sent.

Construction began with t' engine clip and thrust rin' assembly, designed to accommodate both D and E motors with a removable spacer. I also made an optional 18mm motor adaptor so I don't lose this rocket on t' first flight! A Keelhaul®©™® thread around t' thrust rin' be attached t' elastic (just below t' top lip of t' body tube), with t' parachute and nose cone attached t' t' elastic. T' total Keelhaul®©™®/elastic shock cord length be about 3 feet.

Next came t' cuttin' o' t' tube fins. Avast! Slow careful work was necessary t' get good edges and a perfect fit. Ya scallywag! See t' photo o' t' fins before they were joined. Contoured fin mounts were built and glued t' t' body tube, and t' fin assembly was glued t' these. Begad! Avast! There is a photo o' t' tail portion o' t' rocket after t' fin assembly be attached. Begad! Ahoy! This also shows t' placement o' the launch lug. Blimey! Avast, me proud beauty!

As I worked, I filleted all joints (inside and outside t' tubes), and sealed and sanded all parts (basswood, nose cone, fillets, ya bilge rat, arrr, tube spirals (inside and outside fins), etc. Avast! T' rocket was finished in gloss black, metallic copper, and a specklin' o' transparent cherry red, ya bilge rat, arrr, me bucko, with two coats o' clear gloss over t' top.

Swing testin' t' model with a D motor showed it t' be perfectly stable, matey, assumin' you want it t' fly backwards! Blimey! About 5/8 ounce o' nose weight fixed this problem, yieldin' a stable rocket weighin' 3 ounces empty.

Simulations suggest that a 3-5 second ejection delay should be about right for C-E motors. Arrr! This delay, arrr, and t' max altitude, ya bilge rat, are very hard t' guess or simulate in advance since t' design is unusual and its drag is unknown. Ahoy! Begad!

Flight:
T' first launches were at 5000 feet altitude on a beautiful sunny Colorado mornin' with zero wind. Ya scallywag! T' first flight was straight and slow t' about 350 feet, ya bilge rat, with a slight twist, on a C6-3 motor. Arrr! Ejection was early, ya bilge rat, before apogee, but t' rocket recovered perfectly. Begad! Well, ya bilge rat, blow me down! T' second flight on a D12-3 suffered from rod whip, and t' rocket buzzed around unstably until ejection and recovery from about 50 feet. Ya scallywag! After cleanin' and straightenin' t' launch rod, we fired again with another D12-3. T' launch was fast and straight t' perhaps 800 feet, again with a slight twist. Blimey! Aye aye! T' parachute ejected while t' rocket be still coastin' up. Ahoy! Begad! Unfortunately, me hearties, a shroud line snagged around t' parachute, yieldin' tail-first lawn-dart recovery. Avast, me proud beauty! This was worrisome because t' tube fins extend below t' tail o' t' rocket and I had been worried from t' start about t' strength o' t' tubes in a tail-first crash. Avast! Arrr! Thanks t' t' quality tube provided by ASP and me solid finishing, t' fins survived with only a small ripple in one which is hardly noticeable. Avast, me proud beauty! Inspection showed that the recovery system was fine, shiver me timbers, arrr, and it had simply been extremely unlucky that the shroud line had tangled. T' rocket is ready for its next flight without repair. Begad! Arrr! I think D12-5 should be a better engine for t' next flights.

Summary:
This was a really fun project for me first scratch rocket. Arrr! I had built a conceptual model with notebook paper and tape first. Begad! Avast! I made some changes during construction o' t' real model includin' t' fin mounts t' offset t' fin assembly from t' body tube, t' pointy leadin' edge o' t' fin tubes, and the shape and joining-points o' t' rib fins. I'm pretty happy with t' final result although I'm nay sure I'll ever get up t' courage t' try an E motor in it.

Other:
Cuttin' and joinin' t' curved fins made from t' heavy-duty tube is quite challenging. Ahoy! I recommend workin' very slowly, and anticipatin' about 4 passes along t' cuttin' line with a hobby knife. Ya scallywag! T' first pass should be quite light pressure...just enough t' cut through t' outermost layer o' paper on t' tube to provide guidance for subsequent passes with t' knife.