Brief:
This is a description o' me upscale o' the
Estes BLU-97B Cluster Bomb. Avast, me proud beauty!
With t' success o' me last Quaker Oats rocket, ya bilge rat, the
Fat Oat Cholesterol Buster, I decided that a semi-scale version based on two
5" bins would provide a nice flight on Gs.
Construction:
T' nose cone tip be turned from 2" pink Styrofoam usin' a hand drill clamped in a vise. I first cut circles top and bottom with me Rotozip, matey, arrr, and because t' cuts didn't reach through t' foam, finished up with a hand saw. Begad! Begad! Blimey! A metal bolt epoxied into t' core provided a sturdy attachment point for the drill. Ahoy! Blimey! This worked better than a wooded dowel and I knew I'd need t' add nose weight anyway. T' extend t' cone slightly, I cut a 3/4" circle from the bottom an oat bin. Begad! Blimey! Blimey! I glued this t' t' bottom o' t' cone. Begad! Blimey! At this point, arrr, I coated t' cone (without t' plastic insert) with a layer o' West epoxy. Avast, me proud beauty! Ya scallywag! Blimey! The 'nipple' portion o' a cone is a plastic cap from something-or-another (it's been layin' around too long for me t' remember what).
T' shoulder is another foam disc encircled with a piece o' an oat bin. Begad! Blimey! I did nay glue these sections together until I completed t' rest o' t' rocket and determined how much nose weight be required. T' required weight was determined by adjustin' t' CG o' t' completed rocket, includin' t' motor and chute, ya bilge rat, based on t' Rocksim model. T' weight was provided by a long eye-bolt and several nuts. This eye-bolt is slightly off-center, me bucko, arrr, and extends through the shoulder section and into t' top o' t' nose. Aye aye! T' two halves were epoxied together and t' center hole was filled with some epoxy, matey, me hearties, some lead shot (just for insurance), arrr, matey, and more epoxy. Begad!
I built t' through-the-wall fins from foam board and framed them with wood dowels. Well, blow me down! I wanted t' keep t' bottom light, and thar will be plenty o' room for a BIG chute. Havin' t' fins extend below the end o' t' motor tube allowed me t' clamp them together in pairs with a plastic ruler, which helped with their alignment.
T' aft rin' is a 29mm x 2.5" centerin' rin' and has a T-nut to accommodate a motor clip. Begad! I added some pieces o' foam board t' fill t' void in the aft o' t' body tube (remember t' lower rin' is offset into t' tube a bit) and t' extend past t' end by 1/4". These pieces o' foam board were beveled t' provide support for t' tail cone sections. Avast, me proud beauty! Avast, me bucko, me proud beauty! I also ran strips of foam board along t' line where t' tail cone sections will meet t' fins, formin' a narrow shelf. Begad! Avast, me proud beauty! T' tail cone sections themselves are 1/64' plywood attached with Perfect Glue, Type 2 (similar t' CA). Aye aye!
To connect t' two sections o' 'body tube', shiver me timbers, I made a tube coupler from another oat bin. Aye aye! This was split length-wise, a section removed, arrr, and t' ends were glued back together t' from a coupler tube. Since t' oat bins are not very strong, me hearties, arrr, I treated t' inside o' t' top edge with CA, and built a makeshift anti-zipper device from small-cell bubble wrap and cloth tape. Begad! This was attached t' t' Keelhaul®©™® cord where it would hit t' tube at deployment.
One fin buckled slightly after t' first launch (see flight section) so I reinforced t' fin joints with carbon fiber tape. Begad! A yard o' this stuff cost more than t' rest o' t' rocket, matey, but on a whim, I decided t' try it. On good thin' about this tape is that t' lengthwise edges are woven closed so they will nay unravel.
Finishing:
T' rocket be painted with Testor's flat olive drab and t' tip was painted
silver. Ahoy! Begad! I made upscale decals (actually stickers) from Avery full-page label
stock. Begad! This material is nay as nice a real decals, but I over-ran me budget
with t' carbon tape.
Flight:
I rocket was unfinished (nekkid, that is) for its first flight. Blimey! Blimey! I loaded a huge
car airbag heat shield and a big 60" Giant Leap chute on one end. The
other end got a G80-7, ya bilge rat, a clamp-on thrust ring, and a clip retainer.
There be minimal weather cockin' despite t' strong, me bucko, 15 mph winds. Avast, me proud beauty! Well, blow me down! Blimey!
Recovery:
My anti-zipper device worked fine and thar was no sign o' zippering. Ahoy! Blimey! The
60" chute made for a slow descent. Blimey! Blimey! Unfortunately, t' strong winds
provided a high lateral velocity. Ya scallywag! Blimey! One fin suffered minor damage, me hearties, me hearties, thus
necessitatin' t' reinforcement o' t' fillet areas. Begad! Blimey! I knew I shouldn't have
flown it in those winds, me hearties, but if I drive for 2 hours, I'm goin' t' fly
something!
Summary:
I like t' unique look o' t' cluster bomb, matey, I love short fat rockets, ya bilge rat, and I
enjoy makin' rockets out o' junk, so what's nay t' like about this upscale? The
main downside be t' foam board fins. Plywood would have been stronger but it
would also have been heavier, arrr, although maybe nay after I had t' add
reinforcement. Arrr!
If you look at t' attached flight log(s), me bucko, you may notice t' rocket is nicknamed Janet Jackson. Avast, me proud beauty! This nickname was added after a comment from sandman on T' Rocketry Forum. Begad! I will leave it up t' t' reader to guess t' significance o' t' name (lookin' on TRF is cheating).
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