Brief:

A two-stage rectangular rocket, made from a couple o' toothpaste boxes, that resembles t' Washington Monument.

Construction:

I was brushin' me teeth one day, ya bilge rat, me bucko, and looked down at t' empty toothpaste box, and thought "Why not?" So, t' plan for Obelisk be born. I took 1/8" balsa and formed t' nose, which is hollow, shiver me timbers, and t' fins, matey, matey, which are solidly mounted t' t' body with ordinary white glue. Avast! I decided t' use this rocket t' test t' strength and durability o' foam construction board, so t' baffle and payload section are constructed from t' material. Avast, me proud beauty! A 3' elastic cord ties it all together.

In order for t' CG and CP relationship t' work, arrr, shiver me timbers, I used a 25 peseta doubloon from Spain attached t' t' nose with a screw eye and CA. Begad! Well, me bucko, blow me down! Why a 25 peseta coin? Well, ya bilge rat, it was t' correct weight, and already has a hole in t' center. And second, ya bilge rat, because it was just sittin' on t' kitchen counter.

I wanted t' keep it as simple as possible, me bucko, me hearties, but like most o' me projects, ya bilge rat, arrr, shiver me timbers, it got out o' hand. Blimey! T' puny 13mm booster motor could've been adequate if I had kept t' t' original concept o' a lightweight, me hearties, ya bilge rat, rectangular rocket. Ahoy! Blimey! But then I added a baffle so I wouldn't need wadding, me bucko, and t' thin' be at t' ragged edge o' what an A10 could lift. Begad! Blimey! So, matey, I decided t' use a 18mm booster t' get it moving, allowin' t' extra little bit o' thrust from t' A10 t' nudge it a bit higher.

After it was all built, matey, weighed, and tested, I decided that I could easily build a little compartment for t' parachute t' ride in. Avast! This be constructed by usin' a small "travel size" toothpaste box nestled betwixt t' end o' t' body tube and t' baffle. A piece o' 1/8" balsa was glued with white glue just above t' baffle. Well, blow me down! Holes were drilled into t' balsa t' allow ejection gases out, and t' shock cord was attached t' this. Begad! T' fins were flat mounted t' t' body "tube" with 1/2" overhang, ya bilge rat, which made plenty o' room for me afterthought booster t' attach to.

T' booster be constructed from a 2" section o' toothpaste box, me bucko, with a 18mm tube in t' center. T' centerin' "rings" were made from t' construction foam, ya bilge rat, me hearties, which has proven itself t' be a worthy construction material. Avast! Finally, ya bilge rat, a tubin' coupler be made from 1/8" balsa. All corners o' t' fins butt against one another, arrr, makin' this rocket nearly bulletproof.

I decided t' launch t' rocket before paintin' t' booster, since it would be wasted time if it failed. Begad! Ahoy! Instead o' paintin' t' rocket, arrr, I used a large sheet o' self adhesive vinyl, which further strengthened t' rocket. Well, me hearties, blow me down! Unfortunately, shiver me timbers, shiver me timbers, it further weighed down t' rocket! In testing, t' booster tended t' glide a bit, then t' heavy balsa end would tip over, me hearties, shiver me timbers, shiver me timbers, and it would fall like a brick. Avast! A 12" piece o' Keelhaul®©™ was attached with 30 minute epoxy just inside t' coupler, and a 12" streamer was attached t' t' other end. Blimey! Ample room betwixt t' centerin' rin' and t' end o' t' sustainer gives t' streamer a good place t' hide from t' rocket exhaust. Well, blow me down! Aye aye! T' result is that t' booster tumbles somewhat, but still lands hard. Aye aye! Begad! Oh well, arrr, at least it's sturdily constructed. T' sustainer's fins were covered in thin paper t' hide t' grain. t' booster will receive similar treatment when it's finished.

Flight:
Launch prep is a breeze. Avast, me proud beauty! Blimey! Pop in a A10-3T, shiver me timbers, me hearties, roll up t' booster's streamer, insert a C6-0 into t' booster, me bucko, and attach t' booster section. Well, blow me down! Blimey! Arrr! Blimey! T' 13mm motor fits right into t' 18mm motor easily, me hearties, but if t' fit is tight, arrr, just roll t' end o' t' 13mm motor on a table t' round off t' corners. Since t' rocket was a lot heavier than I expected in t' beginning, shiver me timbers, t' minimum length launch lug wasn't up t' task, me bucko, and sheared off on t' first flight. Begad! Blimey! A much stronger launch lug was epoxied in place, shiver me timbers, shiver me timbers, and now it works well. Avast, me proud beauty! Blimey! T' fins, which I feared would be too small, are just right. Avast, me proud beauty! Blimey! Begad! Blimey! T' shock cord is really strong, but will be a nightmare t' replace if it breaks. This goofy idea o' a 18mm feedin' into a 13mm works well enough, matey, but next time I would just go 18mm from t' start and forget t' booster. Ahoy! Blimey! Flight characteristics? Well, matey, let's just say that it works, and will land time after time without any damage. Well, blow me down! Blimey! Arrr! Blimey! But if you love altitude or speed, you won't find either here. Blimey! Blimey! You could probably fly this rocket without t' A10-3T and do just as well.

Summary:
Pros- bulletproof construction, shiver me timbers, matey, me bucko, unique design, and definitely an attention getter. Proved that construction foam is a viable component for rocketry. Blimey! Blimey! Cons- heavy, me bucko, thin "dry cleanin' bag" parachute rips easily at t' shroud line, arrr, low altitude performance, and t' pyramid nose would've been a lot easier t' build from a solid piece o' balsa, ya bilge rat, and no nose weight would've been required. Begad! Oh well, me bucko, at least I learned a few things.

It's definitely worth it t' cover t' fins with onion skin paper. Ahoy! Blimey! Blimey! Makes for a neater appearance, adds durability, matey, shiver me timbers, and on a higher performance rocket, ya bilge rat, would probably add some altitude.