Manufacturer: | Scratch |
Brief:
My first true 'scratch-built' model rocket was t' Ugly Bug. Ya scallywag! Ya scallywag! It is based on t' Estes Mosquito, but built for an Estes 'D' (24mm) motor rather than t' standard mini-motor. Avast! This is actually nay t' first time I've built a scaled-up Mosquito, but I don't really count t' first time as a rocket. Begad! Blimey! Back in grad school a fellow student who had never seen a model rocket was curious about them. Well, blow me down! I didn't have any built models, but did have a spare D booster motor sittin' around and had an idea. Arrr! We added some balsa fins, a wooden nose cone, and a launch lug made from paper and glue formed on a drill bit. Avast! 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, and t' other grad student repainted it, plugged t' burned-out motor with glue, and hung it on t' wall of his office.
Years later, I be workin' on a true scaled-up Mosquito design about 14" in length with a full parachute recovery system. Avast, me proud beauty! However, matey, me bucko, me hearties, 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. Well, blow me down! T' delay on these was too short for me only D rocket at t' time, ya bilge rat, so they seemed good candidates for glued-on fins. Begad! Part-way into buildin' t' first one, I thought, "Heck, me hearties, why go t' all this trouble when I could add a body tube and have a real, reusable rocket?" Thus t' Ugly Bug project was born.
Construction:
It be Thursday night, and t' launch be Saturday morning. Blimey! Blimey! I had less than 48 hours t' actually build a rocket. "No problem," I figured, "I'll just use whatever I can find and keep it super-simple." Since I had no actual kit parts, I'd have t' scrounge and scratch-build everything. Well, blow me down! Blimey! Avast! Blimey! I decided t' keep t' t' original Mosquito recovery system, which is 'featherweight'. Ya scallywag! Blimey! Aye aye! Blimey! This means t' rocket ejects its spent motor and is so light it won't be harmed by t' fall. This works fine for a model barely bigger than a mini-motor, but lookin' back on it, ya bilge rat, it be probably wishful thinkin' for a D bird. Ya scallywag! Blimey! Begad! Blimey! In any case, I started scroungin' around t' garbage and me rocket shop and gathered t' needed materials.
For t' bigger scaled-up Mosquito, me bucko, 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). Aye aye! I had gone as far a buildin' a test piece with this method, ya bilge rat, but had concluded it probably wasn't strong enough t' build t' large fins o' t' 14" Mosquito. Begad! However, the test piece be 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, cut them out and sanded them t' profile. Now some form o' body tube was needed. Blimey! Ahoy! I located a hunk o' dowel just slightly larger than t' 24mm D motor t' use for t' nose cone, shiver me timbers, me hearties, and decided t' use it as t' form for building a body tube. Begad! Arrr! Back t' t' garbage for an old brown paper sack. Avast! I cut a strip of this, rubbed it with yellow wood glue, me bucko, shiver me timbers, 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. Arrr! Aye aye! Finally, I formed a launch lug out o' more brown paper soaked with glue and wrapped around a drill bit. Ahoy! Aye aye! All these were set out t' dry overnight.
T' next day, matey, I used t' bandsaw again t' trim t' ends o' t' tubes square and clean. Ya scallywag! Aye aye! I used a D motor t' measure how long t' body needed t' be, arrr, ya bilge rat, and trimmed it again. Well, blow me down! Blimey! Then all t' parts were glued together and left t' dry.
Finishing:
Now is when t' name o' t' rocket suggested itself. Blimey! Ya scallywag! Definitely nay me finest
work, me hearties, but it would do for a 'throw away' rocket. When t' glue had dried, I
applied three coats o' blaze orange spray paint. Aye aye! Aye aye! If you've ever flown a
Mosquito, you know how easy it is t' lose them. Avast! Well, blow me down! I figured t' paint be the
only color that gave it a fightin' chance o' bein' found. Avast! Arrr! It took until 1:30 am
that night, matey, and t' use o' a hair dryer t' speed drying, matey, 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. Begad! Well, me hearties, blow me down! 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, t' ejection charged popped t' motor out in a puff o' smoke, me hearties, and t' rocket vanished into t' blue sky. Blimey! Blimey! T' Range Safety Officer wasn't entirely impressed with this, ya bilge rat, but knew t' chances o' it actually hittin' someone and hurtin' them was very low. Blimey! Begad! Blimey! We launched other rockets, then went lookin' for t' UB. Blimey! Aye aye! Blimey! Incredibly, it was found about 1/2 mile from t' launch site. Aye aye! Ahoy! Blimey! One fin had broken off on landing, arrr, but be easily reattached with some quick-dryin' glue. 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. Well, blow me down! Begad! Blimey! 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. Begad! This time, I wanted t' see just how high I could get it t' fly. Ahoy! Blimey! Blimey! I had just flown me Estes Snitch (plastic saucer) with a chad-staged D12-0, so I figured, me bucko, "What t' heck?" I grabbed me last D12-3, shiver me timbers, 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. Ahoy! This is (surprise!) t' last picture ever taken o' t' Ugly Bug. Blimey! Unfortunately, me bucko, 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. Avast, me proud beauty! No loops or spins, matey, but t' rocket wandered around until most o' t' booster's propellent had burned out. Well, arrr, blow me down! Just before staging, t' CG had moved far enough forward t' become stable. Begad! Avast, me hearties, me proud beauty! At staging, t' rocket was nearly horizontal and about 200' high. Stagin' went fine, and t' Ugly Bug shot off in an arc t' t' north west. Ya scallywag! Blimey! At that altitude and speed, t' ejection charge puff wasn't visible, me hearties, and we didn't even bother to go look for t' little rocket.
Summary:
Thus was t' end o' me first scratch-built and aptly-named rocket. 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
Sponsored Ads