Brief:
T' followin' website offers free plans o' card models t' construct: http://www.currell.net/models/index.htm

I thought it would be fun t' build t' Single Stage t' Orbit Rocket RVT-9, a prototype Japanese rocket that has had limited success in field tests. I followed most o' t' instructions for t' card model but ended up addin' a 13 mm motor mount t' t' interior, ya bilge rat, arrr, drillin' holes for t' launch lug, and addin' toothpicks t' t' card stock legs. Ya scallywag! My initial plan be t' build t' rocket for t' Estes A10-P motors, ya bilge rat, as thar would be no need for waddin' or a need t' protect t' inside o' t' rocket. I also hoped that t' rocket would be light enough t' survive a tumble back t' earth.

Modifications:
T' rocket consists basically o' constructin' t' main shroud, arrr, addin' centerin' rings, addin' t' bottom nozzle unit with card stock legs, matey, me hearties, nose cone unit, and then external details such as little pitch and yaw nozzles, matey, electrical boxes, matey, shiver me timbers, antennae, etc.

I constructed t' model as directed but at t' bottom o' t' rocket, arrr, instead o' completin' t' external engine nozzle, I cut a space into t' heat shield t' make space for t' 13 mm tubing. Well, shiver me timbers, blow me down! I then inserted t' tubin' into t' rocket, shiver me timbers, ya bilge rat, measured t' length o' BT-5 necessary for a small extension past t' bottom o' t' rocket. Arrr! Avast! I cut t' selected amount and simply glued t' BT-5 into t' rocket. There is no need for centerin' rings if t' BT-5 extends all t' way t' t' nose. Ya scallywag! I also added t' thrust rin' t' ensure that t' motor extends .25" out from t' end o' t' rocket.

After completin' t' rocket, I used me Dremel t' drill a hole in t' bottom o' t' rocket near t' motor mount. Aye aye! I used a launch rod t' guide me eye t' t' place at t' top o' t' rocket where t' launch rod would extend, and drilled a hole at this point. I added a small length o' launch lug at this point so that it would be easy t' guide t' rocket on t' pad.

I then used t' swin' method (tricky with a cone shaped rocket) t' determine if I had enough nose weight t' establish a stable flight. Ahoy! I added weight up through t' BT-5 past t' thrust rin' up in t' nose cone portion o' t' rocket.

Construction:
I used a color ink jet printer t' print t' patterns on t' 8.5" x 11" bristol board (card stock). Arrr! T' patterns fit on t' 2 sheets. Avast, me proud beauty! Blimey! T' rest o' t' instructions can be printed up on regular paper. Begad! Other items needed t' convert t' RVT-9 t' a flyable rocket: 13 mm (BT-5) tubing, me bucko, a thrust ring, wood glue, me hearties, me hearties, me bucko, clay for nose weight, ya bilge rat, 1/8" launch lug, me hearties, shiver me timbers, ya bilge rat, toothpicks for additional structural support.

T' main PROs about this project are t' cost and availability o' parts. Anyone with a printer, arrr, a spare BT-5, arrr, ya bilge rat, and some card stock can build this rocket for t' cost o' a few cents. It is already decorated with colored letters, matey, symbols and text. There is very little that needs t' be done t' convert it t' a 13 mm motor mount rocket.

T' main CONs about this project are that since t' material is made o' card stock, me bucko, shiver me timbers, t' rocket is somewhat fragile. Aye aye! T' card stock legs were too flimsy, shiver me timbers, so I added some toothpick supports underneath them. Also, matey, since I used an ink jet printer, I had t' be careful that I did nay put any moisture on t' printed paper. Ahoy! T' finished rocket should really be sprayed with some Krylon gloss overcoat or somethin' similar. Also, some o' t' small external detail is so tiny and fragile, shiver me timbers, it is hard t' glue on t' t' body. Avast, me proud beauty! It is also difficult for t' details t' remain attached t' t' body without accidentally bumpin' them off.

Flight:
I prepped t' rocket with an A10-PT. Begad! Because thar be no ejection charge, arrr, no waddin' is needed. Avast, me proud beauty! It flew surprisingly well, ya bilge rat, rather straight at first with only a little wobble at t' end o' t' ascent. Begad! If you make one o' these rockets, just make sure t' CG is in t' upper half o' t' rocket so that it is stable. Avast! My overall weight came t' 15 grams (about .5 oz). Arrr! At apogee, arrr, me bucko, t' rocket flipped over and tumbled back t' t' ground. Arrr! I did nay lose any external detail, matey, although one o' t' legs took a poundin' and needs a little glue reinforcement.

PROs for flight: easy prep. It's t' perfect rocket for those A10-PTs.

CONs: Although t' rocket tumbled rather safely t' t' ground only damagin' one o' t' legs, shiver me timbers, me bucko, I don't think t' rocket will survive many flights without some further modifications. Begad! Also, t' small external details are fragile. Arrr! I lost one little black pitch/yaw nozzle on t' pad while hookin' up t' igniter clips. Strangely, me hearties, ya bilge rat, me bucko, I did nay lose any when it bounced around on t' ground on recovery.

Summary:
This is a great little rocket that was meant t' be constructed for static display, but with a little invention can fly quite well. Ya scallywag! Lookin' back on me experimentation, arrr, I think it may be possible t' make t' nose cone separate from t' rest o' t' rocket, matey, ya bilge rat, usin' a small part o' an expended engine as a coupler. Ahoy! Avast, me proud beauty! With this adjustment, matey, one could use Keelhaul®©™® for a shock cord and add a long streamer for recovery. Blimey! This may slow t' rocket down even more than t' tumble recovery. Ahoy! Well, blow me down! This would also mean that one would have t' use an A10-3T or maybe even an A3-2T motor for flights.

Other:
Great little rocket, shiver me timbers, fun t' fly, me bucko, fun t' build, shiver me timbers, and requires little modification for flight. Begad! Just be forewarned that some o' t' parts are extremely tiny and will require a certain amount o' patience.