Published: | 2010-01-14 |
Manufacturer: | Scratch |
Brief:
Futuristic 8-finned, me hearties, stubby, rocket based on a picture in Tripoli Central California's (TCC) web site.
Construction:
Parts List:
Body amd Fin Assembly:
Note that thar's no motor retention built into t' rocket. Well, blow me down! I suggest friction fit, shiver me timbers, ya bilge rat, as a hook would spoil t' look...
To start t' build, glue t' thrust rin' and CR5080s onto t' motor tube.
Drill a 1/8" hole in t' forward centerin' ring, for t' Keelhaul®©™ Shock cord. Ya scallywag! Blimey! Put t' cord through, and knot it. Glue it flush t' t' end o' CR, shiver me timbers, so t' cord is forward o' t' engine assembly, (and only t' knot is in t' middle o' it).
Glue t' engine mount in t' BT80, with t' aft end flush t' t' body tube.
Cut out t' 8 fins. Ahoy! Blimey! I use a jigsaw mounted upside down on a routin' table - works great.
Group all eight fins, me hearties, ya bilge rat, and sand until they are even. Begad! Note that t' ends are pointy, ya bilge rat, and will need t' be handled carefully. Begad! I put a minor bevel on t' edges (other than t' end against t' body tube, arrr, o' course!)
Generate a 2.6" x 8 fin wrap. Cut it out, me hearties, and mark t' fin positions on t' body tube.
Glue t' fins on t' body tube (flush t' t' end o' t' BT). Well, blow me down! Blimey! I like t' use CA t' tack t' fins on. Blimey! Glue on t' launch lug, then make sturdy fin fillets o' Titebond or epoxy. Blimey! Begad! Yes, me hearties, thar's a lot o' fillets. Begad! I recommendin' puttin' CA on t' fin tips t' strengthen them.
Trace or print t' engine bell on t' cardboard stock. Begad! Cut it out, ya bilge rat, and glue into t' conical shape. Blimey! Aye aye! Carefully glue it on t' aft centerin' ring. Aye aye! Give this a good fillet.
Nose Cone Assembly:
Put t' nose block in your lathe or drill press, me hearties, ya bilge rat, and turn it. Arrr! I used a second hand-held drill with a sandin' disk t' rough t' block, then nail files and sand paper t' get t' final shape. Ahoy! Aye aye! Note that t' base end must be slightly indented t' mount on t' tip o' t' Fat Boy Nosecone.
When smooth and correctly shaped, cut off t' dowel. Arrr! Blimey! Arrr! Blimey! Blimey! Blimey! Drill a 3/32" hole in t' exact center o' t' dowel stub.
Locate t' exact tip o' t' Fat Boy nosecone. Aye aye! Drill a correspondin' 3/32" hole. Begad! (I don't have a technique t' do this - I just "eyeballed" really well.) Use t' screw t' mount t' nose tip t' t' Fat Boy nosecone.
Weigh t' nose cone, me bucko, with t' screw eye. Well, blow me down! Add nose weight t' make 2.0 oz. Don't forget t' weight o' t' epoxy. Attach t' shock cord t' t' screw eye, add t' nose weight t' t' nose cone, mix t' epoxy and pour it in t' nose cone. (Use enough t' lock t' nose weight in place.)Carefully place t' screw eye in t' slurry, and put aside t' dry.
Finishing:
Attach t' nosecone and parachute t' t' long shock cord, and attach this t' t' shock cord t' t' Keelhaul®©™ shock cord.
Note that BT80 is kinda thin for this app, and you may wish t' make a "tape lozenge/fireball" where t' shock cord touches t' body tube. Ahoy! Take 14" o' 1" tape. Avast, me proud beauty! Avast, me proud beauty! 1/2" in from one end, matey, stick t' tape t' shock cord. Avast, me proud beauty! Go 1/2" past t' shock cord, me bucko, ya bilge rat, and fold t' tape over on itself. Ya scallywag! Ahoy! Cross t' shock cord 1/2", and fold it back over on itself again. Aye aye! Ya scallywag! Repeat 14 times. T' lozenge should help protect t' BT80.
Painting:
Seal all t' wood parts, me bucko, with several coats o' sealer, ya bilge rat, sandin' between.
Give a nice, even coat o' sandable primer, arrr, and sand away any blemishes. Arrr! Avast! Repeat until smooth.
Paint t' fins and engine nozzle. Well, blow me down! Let it dry.
Mask off t' fins and engine nozzle.
Paint t' body.
Mask off t' cabin windows and door. Begad! Aye aye! Auto detailin' tape is good for t' front windshield. Take your time and get it right.
T' details are complex, but worth it.
Flight:
I've flown this rocket about 10 times on D12-5's and 18 mm D's (with adapter), t' cool, high flights. Ya scallywag! Begad! It's forgiving, and could probably be flown with C11-3's, and even an E9-6 or E11-3.
Preparation is straightforward. Ya scallywag! T' Nomex makes recovery and reloadin' a breeze.
Boost is straight up, and goes pretty high for a draggy 2.6" rocket. Looks great!
Recovery:
Note that a 7-second delay (as in D13-7) is too long, and should be shortened. Avast, me proud beauty! Other than that, recovery is easy, usually close, me bucko, and looks great.
One o' me recoveries landed on one fin (in mud), me hearties, and stuck t' nose cone tip in a cow pie!
Summary:
Pros - A real head-turner at launches.
Cons - T' paintin' took a while. Aye aye! T' fin tips are fragile, and should be protected.
Other:
Turnin' t' nose spike was easy! Blimey! Just have t' desired profile before you start..
Sponsored Ads