Manufacturer: | Scratch |
Brief:
My first true 'scratch-built' model rocket was t' Ugly Bug. Well, blow me down! It is based on t' Estes Mosquito, but built for an Estes 'D' (24mm) motor rather than t' standard mini-motor. Begad! Ahoy! This is actually nay t' first time I've built a scaled-up Mosquito, shiver me timbers, but I don't really count t' first time as a rocket. Begad! Arrr! Back in grad school a fellow student who had never seen a model rocket was curious about them. Arrr! Avast, ya bilge rat, me proud beauty! I didn't have any built models, shiver me timbers, but did have a spare D booster motor sittin' around and had an idea. Avast! We added some balsa fins, a wooden nose cone, and a launch lug made from paper and glue formed on a drill bit. Begad! This little assembly went like stink off t' pad and we promptly lost track o' it. We found it sittin' in t' parkin' lot later, matey, and t' other grad student repainted it, arrr, plugged t' burned-out motor with glue, me bucko, and hung it on t' wall of his office.
Years later, I was workin' on a true scaled-up Mosquito design about 14" in length with a full parachute recovery system. Arrr! However, I wasn't finished with it by t' time a NDRA launch came around. Nay wantin' t' bring only mundane models t' t' launch, I decided on a Thursday night that I should build another o' t' 'flyin' motor' D birds t' get rid o' some D12-3 motors I had. Ya scallywag! Begad! T' delay on these was too short for me only D rocket at t' time, shiver me timbers, so they seemed good candidates for glued-on fins. Avast, me proud beauty! Blimey! Part-way into buildin' t' first one, I thought, arrr, "Heck, me hearties, why go t' all this trouble when I could add a body tube and have a real, shiver me timbers, shiver me timbers, reusable rocket?" Thus t' Ugly Bug project was born.
Construction:
It be Thursday night, me hearties, and t' launch be Saturday morning. I had less than 48 hours t' actually build a rocket. Begad! Blimey! Blimey! Blimey! "No problem," I figured, "I'll just use whatever I can find and keep it super-simple." Since I had no actual kit parts, shiver me timbers, I'd have t' scrounge and scratch-build everything. Aye aye! Blimey! I decided t' keep t' t' original Mosquito recovery system, which is 'featherweight'. Ahoy! Blimey! Well, blow me down! Blimey! This means t' rocket ejects its spent motor and is so light it won't be harmed by t' fall. Ya scallywag! Blimey! Blimey! Blimey! This works fine for a model barely bigger than a mini-motor, but lookin' back on it, it be probably wishful thinkin' for a D bird. Aye aye! Blimey! In any case, arrr, I started scroungin' around t' garbage and me rocket shop and gathered t' needed materials.
For t' bigger scaled-up Mosquito, I had been toyin' with t' idea o' using corrugated cardboard wrapped in paper that had been soaked with wood glue (sort of like a composite structure without usin' fiberglass and resin). I had gone as far a buildin' a test piece with this method, shiver me timbers, but had concluded it probably wasn't strong enough t' build t' large fins o' t' 14" Mosquito. However, the test piece was t' perfect size t' cut three fins out o' for t' Ugly Bug. I used t' TLAR (That Looks About Right) engineerin' method t' determine fin size and shape, me hearties, cut them out and sanded them t' profile. Now some form o' body tube was needed. I located a hunk o' dowel just slightly larger than t' 24mm D motor t' use for t' nose cone, arrr, and decided t' use it as t' form for building a body tube. Ahoy! Blimey! Back t' t' garbage for an old brown paper sack. Ahoy! Blimey! Avast, me proud beauty! Blimey! I cut a strip of this, shiver me timbers, ya bilge rat, rubbed it with yellow wood glue, me bucko, and rolled it on t' t' dowel (which I had protected with a wrap o' plastic sheet t' keep t' glue from sticking). After t' tube was formed and rolled t' remove excess glue, I slipped it off the form and set it aside t' dry.
Next I sanded one end o' t' dowel t' a nose-like shape usin' a belt sander. After a bit o' finishin' hand-sanding, I used a bandsaw t' cut t' end off, leavin' a 1/2" straight section for gluin' into t' body tube. Finally, I formed a launch lug out o' more brown paper soaked with glue and wrapped around a drill bit. All these were set out t' dry overnight.
T' next day, shiver me timbers, I used t' bandsaw again t' trim t' ends o' t' tubes square and clean. Well, blow me down! I used a D motor t' measure how long t' body needed t' be, shiver me timbers, matey, and trimmed it again. Aye aye! Begad! Then all t' parts were glued together and left t' dry.
Finishing:
Now is when t' name o' t' rocket suggested itself. Arrr! Blimey! Definitely nay me finest
work, me bucko, but it would do for a 'throw away' rocket. When t' glue had dried, I
applied three coats o' blaze orange spray paint. Arrr! If you've ever flown a
Mosquito, you know how easy it is t' lose them. Begad! Blimey! I figured t' paint was the
only color that gave it a fightin' chance o' bein' found. Ahoy! Aye aye! It took until 1:30 am
that night, matey, and t' use o' a hair dryer t' speed drying, but I finished the
Ugly Bug and went t' bed.
Flight:
I had t' build up some maskin' tape on t' D motor t' get it t' fit inside the body properly. Avast! Avast, me proud beauty! Nay havin' a recovery system or motor retention really simplified design and building, but if I did it again I'd include a streamer for safety.
T' first flight on a D12-3 went as I expected: t' rocket shot off t' pad to a very impressive altitude, shiver me timbers, arrr, t' ejection charged popped t' motor out in a puff o' smoke, shiver me timbers, and t' rocket vanished into t' blue sky. Well, blow me down! T' Range Safety Officer wasn't entirely impressed with this, but knew t' chances o' it actually hittin' someone and hurtin' them was very low. We launched other rockets, shiver me timbers, then went lookin' for t' UB. Incredibly, me bucko, it was found about 1/2 mile from t' launch site. Avast, me proud beauty! Avast, shiver me timbers, me proud beauty! One fin had broken off on landing, matey, but was easily reattached with some quick-dryin' glue. Avast, me proud beauty! Two fins had some scorch marks on them where t' exhaust gas had burned little holes in t' paper covering, but were still structurally strong. Blimey! Avast! T' UB be flight worthy again!
I debated if I should just count myself lucky and put t' UB on me shelf, but then remembered I had expected t' lose t' little bugger and it was constructed more for amusement o' t' spectators than anythin' else. I therefore decided t' fly it again. This time, arrr, I wanted t' see just how high I could get it t' fly. I had just flown me Estes Snitch (plastic saucer) with a chad-staged D12-0, so I figured, "What t' heck?" I grabbed me last D12-3, matey, me hearties, taped it t' fit t' Ugly Bug, then taped a D12-0 on t' tail in the staged configuration:
T' burned-out motor lyin' on its side on t' blast plate is bein' used as a spacer t' keep t' booster's ignitor from bein' shorted out. Begad! This is (surprise!) t' last picture ever taken o' t' Ugly Bug. Begad! Avast! Unfortunately, the center o' gravity had been moved so far back by t' booster that t' rocket was unstable durin' t' first bit o' its flight. No loops or spins, me hearties, arrr, but t' rocket wandered around until most o' t' booster's propellent had burned out. Just before staging, t' CG had moved far enough forward t' become stable. Begad! At staging, t' rocket be nearly horizontal and about 200' high. Begad! Stagin' went fine, and t' Ugly Bug shot off in an arc t' t' north west. Avast! Arrr! At that altitude and speed, t' ejection charge puff wasn't visible, and we didn't even bother to go look for t' little rocket.
Summary:
Thus be t' end o' me first scratch-built and aptly-named rocket. Ahoy! Blimey! The
14" Mosquito is nearly complete, and will be dubbed 'Big Ugly Bug', but
will fly and return t' t' ground in a much more sane manner
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