Construction Rating: | starstarstar_borderstar_borderstar_border |
Flight Rating: | starstarstarstarstar_border |
Overall Rating: | starstarstarstarstar_border |
Published: | 2011-08-14 |
Manufacturer: | Scratch |
Style: | Ring/Tube/Cone Fin |
Personal Challenge: A workin' model built from and themed on Toilet Paper Rolls, Rear Ejection (of course!) and fly-able with C engines
(*Regardin' "High Quality Toilet Paper Rolls," t' cores from t' industrial strength extra large rolls used in hospitals and office buildings by professional janitorial services are thicker, smoother, and tougher than t' stuff you get at t' grocery store. Avast, me proud beauty! Blimey! T' spirals are however very deep.)
Challenge: Build a rocket based on theme o' Uranus Explorer (but keep it PG rated)
At t' same time I be buildin' t' rocket (actually t' second rocket, t' Uranus Explorer 1 be a dismal failure) I was makin' up a story that went along with t' rocket. Begad! Blimey! I think t' best place t' put that is up front in this review, so here it is.
INTERSPACE TELEX FROM SPACE COMMAND
URGENT: You have been ordered t' take IMMEDIATE command o' t' Uranus Explorer II.
BACKGROUND: In t' first half o' t' 21st century, shiver me timbers, concerns on Earth mounted regardin' global warming. Ya scallywag! While thar was a great uproar about changin' human behavior t' combat this menace, arrr, shiver me timbers, t' problem solved itself in t' second half o' t' century. While t' well-meanin' efforts o' t' "Greens," as they came t' be called, me bucko, arrr, matey, may have had some impact, me bucko, t' finite supplies o' fossil fuels expired by 2075. Blimey! Aye aye! In addition, matey, t' fight t' obesity epidemic, t' fast grub enterprises were vilified by t' population. Ronald McDonald was hung in effigy in several countries. Begad! Avast! Since beef hamburgers were t' main stock in trade for these restaurants, t' demand for beef largely expired with t' fast grub franchises. Well, blow me down! Well, me hearties, blow me down! T' final major source o' greenhouse gasses, t' cattle farms, also went t' way o' t' dinosaur. Blimey! Avast, me proud beauty! T' global warmin' scare be over.
T' loss o' cheap fuel and fast foods led t' a progressive sense o' dissatisfaction among t' people o' Earth, ya bilge rat, shiver me timbers, who attempted t' drown their sorrows in entertainment. Begad! VCRs and DVD players gave way t' IPods, Androids, matey, matey, Playstations, me bucko, Wiis, me bucko, me bucko, and other devices, me bucko, all o' which shared two features. Ya scallywag! First, they required electricity. Aye aye! Ahoy! Second, me bucko, they were a mindless waste o' time.
To replace t' fossil fuels, t' people o' Earth maximized their use o' renewable energy sources, includin' Wind, Geothermal, shiver me timbers, Hydroelectric, shiver me timbers, and Solar. Avast! Blimey! T' first three were largely limited by geography. Arrr! Blimey! Solar, however, was only limited by surface area. Avast, me proud beauty! Blimey! By t' year 2125, solar "farms" had sprung up over much o' t' Earth’s surface, includin' Antarctica, and floatin' solar "mats" covered much o' t' oceans. Ahoy! Low Earth Orbit solar satellites created a virtual "traffic jam" in t' skies, me bucko, t' t' chagrin o' terrestrial astronomers. Ya scallywag! Lookin' up at t' sky at night, more stars "moved" than remained in once place.
T' combination o' t' loss o' greenhouse gas generators and t' impact o' solar collectors shadin' much o' Earth’s surface as well as fillin' t' skies had an effect that should have been anticipated--- t' Earth's climate was headin' for a second Ice Age. Temperatures plummeted.
Many different plans t' restore t' greenhouse gas "blanket" were attempted. Avast! A nationwide chili marathon was probably t' most grandiose. It had little effect on t' global atmosphere, but resulted in numerous hospitalizations throughout t' state o' Texas dues t' t' accumulation o' noxious gases. Blimey! Ya scallywag! In desperation, t' people o' Earth looked t' t' skies for help. Aye aye! T' United States, arrr, me bucko, shiver me timbers, once an importer o' fossil fuels, now developed a plan t' import greenhouse gases from space.
Of t' four planetary gas giants, shiver me timbers, t' highest concentrations o' methane are found around Uranus, at roughly 2% o' t' atmosphere by volume. Blimey! While further away than Saturn and Jupiter, manned expeditions t' Uranus in 2186 found t' planet had a rocky core with numerous central caverns. Blimey! Concentrations o' methane within t' caverns approached 75%. Arrr! Unlike Saturn and Jupiter, t' caverns could be sealed, arrr, cleared o' t' methane, matey, heated, arrr, matey, and pressurized. In other words, thar could be life inside Uranus.
Drillin' operations began in 2192, me bucko, and t' planet was formally colonized under t' leadership o' Admiral Ezekiel Koli in 2199. T' fecundity o' E. Aye aye! Koli's descendents became legendary, and within 5 years t' colonists had spread throughout t' bowels o' t' planet. Blimey! Methane gas generated within t' rocky core was diverted t' natural "vents" on t' planet surface. Begad! Ahoy! This gas was collected in Surface Repositories (dubbed "SuPositories.") T' SuPositories were then harvested by tanker ships and t' gas be transported t' Earth. T' effort has been thus far successful. Earth's temperatures have stabilized and are gradually returnin' t' 21st century levels. Aye aye! T' only casualty be t' state o' Utah, which seceded from t' Union when t' restoration o' "normal" temperatures forced them t' abandon plans for year-round skiing.
Durin' t' drillin' operations on Uranus, miners discovered rich deposits o' Amodium. Avast, me proud beauty! Existin' in two chemical isomers, t' "L" or levo form and t' "D" or dextro form, Uranian Amodium be predominantly in t' D isomer. Valued for its medical properties, Amodium-D is extremely useful in t' treatment o' dysentery. Well, blow me down! Ya scallywag! Earth's Amodium supplies were exhausted in t' early 21st century in a vain attempt t' stem t' tide o' large fecal outflows from Washington, matey, D.C. Uranus produces 80% o' t' pharmaceutical grade Amodium-D in t' solar system. T' only other major supply o' Amodium-D is in t' asteroid belt. Arrr! Avast, matey, me proud beauty! Tanker ships, notorious for poor hygiene, shiver me timbers, were plagued with dysentery and t' production o' Amodium around Uranus rivaled t' methane minin' operations in profitability.
T' growin' population inside Uranus yearned for t' same amenities and distractions as their distant Earthly cousins. Well, me hearties, blow me down! Entrepreneurs, arrr, ever anxious t' make a credit, established venues on t' Uranian satellites, ya bilge rat, includin' a Disney Theme Park, me hearties, "Part o' Your World," on t' satellite Ariel, arrr, a Lane Bryant Woman's Clothin' outlet store on t' satellite Titania, and a romantic bed and breakfast getaway, matey, matey, "A Quiver o' Love" on t' satellite Cupid. Avast! By 2250, Uranian commerce had established a respectable amount o' regularity.
Unfortunately, t' hygienic habits o' t' Tanker ship crews did nay improve. Begad! Begad! Due t' failure in interspace decontamination procedures, one or more tankers have carried a type o' "animal fungus" from t' asteroids t' t' surface o' Uranus. Avast! These vile creatures reproduce rapidly and are incredibly adherent t' t' rock and ice surface o' t' Uranian core. Well, blow me down! They are particularly attracted t' t' relative heat around t' vents o' Uranus. Begad! Dubbed, shiver me timbers, ya bilge rat, "Cling-Ons" by t' colonists, t' invaders have destroyed t' SuPositories and have multiplied t' t' extent that they are now obstructin' many o' t' methane outlets. Aye aye! Ya scallywag! T' buildup o' pressure behind t' vents is reachin' dangerous levels, producin' dyspepsia, shiver me timbers, nausea, and vomitin' among t' population o' t' planet. Minin' operations o' Amodium-D have ground t' a halt. Ya scallywag! Because thar be no local supply, an outbreak o' dysentery on t' satellite Oberon has required importation o' Amodium from t' asteroid belt. Well, blow me down! This has put an incredible load on an already strained interplanetary supply system.
T' situation is now CRITICAL.
We have deployed Remotely Operated Infrared Detectors (ROIDs) within all t' major vents t' monitor t' situation. Well, blow me down! Blimey! T' ROIDs will detect focal temperature increases which herald obstruction. Additional SuPositories have been prepared t' replace those destroyed by t' Cling-Ons. Blimey! Blimey! T' Jovian and Saturnine Fleets have been redirected t' assist in t' emergency.
T' initial scout ship, matey, me bucko, t' Uranus Explorer, was mothballed in 2195. Avast, me proud beauty! Begad! It has been recommissioned for t' rescue effort. Ya scallywag! T' previous BVD-1 subspace engine has been upgraded t' t' BVD-2. Avast, me proud beauty! Aye aye! T' ship has also been augmented by 4 Procto and Gamble Sharmin "Ultra" outboard engines t' give it interplanetary capability at 0.25 light speed.
Your mission is as follows:
Addendum: On successful completion o' this mission, you and your spouse are authorized a 30 day furlough at t' "Quiver o' Love" on Cupid. Blimey! Remember, me hearties, matey, with 27 satellites, me hearties, me hearties, arrr, thar be always a full moon around Uranus.
END TRANSMISSION
Back t' t' review. Begad! Goals o' t' rocket buildin' were as follows:
After buildin' t' Estes Porta-Pot Shot, and readin' notes from a reviewer who suggested a rear-ejection model, shiver me timbers, started t' think o' other designs sort o' on t' same theme. Aye aye! Blimey! Original design became t' Uranus Explorer 1 (UE1), ya bilge rat, (which will be fairly similar t' t' UE2, matey, described here. Ya scallywag! I found that usin' only two rolls for t' nose-cone fuselage combo resulted in a stubby rocket that I could nay get stable (I know, me hearties, I built it and tried. Blimey! Arrr! For some reason Tim Van Milligan doesn't have Toilet Paper tubes in t' RockSim inventory. Ya scallywag! Go figure!) So t' lengthen t' fuselage, had t' use two rolls connected (alternative would have been t' use a single paper towel roll, ya bilge rat, but that would have violated t' theme. Would have had t' call it t' Brawny or t' Scrubber, or somethin' else. But I digress...) You say, me bucko, no problem, a coupler would work for this. Problem, arrr, me bucko, me bucko, since I pre-determined t' use aft end ejection, shiver me timbers, I needed a pristine smooth inner contour, arrr, so a (standard) internal coupler wouldn't work. Avast, me proud beauty! So I went with an external coupler. Avast, me proud beauty! This o' course was aerodynamically suboptimal, matey, but since I wasn't plannin' t' set an altitude or duration records, arrr, was acceptable. Ahoy! Avast, me proud beauty! So I used an external coupler cut from another tube. Blimey! I figured I would put t' launch lug in t' gap later (had I really thought it through, would have remember I could hide a launch lug in t' tube fins.) This still left a small step-off or "transition" on t' inside where t' two tubes butted together. Aye aye! I ran maskin' tape from end t' end along t' inside so that thar were no transitions t' trap or catch t' engine pod and recovery devices durin' aft ejection.
Next problem: t' nose cone. First, me bucko, matey, nay sure that toilet paper roll centers really come in a standard size for nose cones. Blimey! Blimey! Second, me bucko, I'm cheap. Ya scallywag! Blimey! Third, arrr, wanted t' keep overall weight o' t' body o' t' rocket light (more on this later.) 4rth, shiver me timbers, wanted t' use as many TP rolls as possible. Arrr! Wondered---- how could I make a nose cone out o' a toilet paper roll?
By cuttin' 16 length-wise cuts nearly t' t' end o' t' roll, me hearties, matey, then cuttin' a diagonal out o' each section, I be able t' create a roughly Ogive cone. Connected t' tips with tape. Ya scallywag! Put a "shoulder" (again cut from another TP roll) on t' anterior end o' t' body tube. Begad! Attached this with CA t' t' previous two tubes I now have a fuselage (one-piece with t' nose cone) just under three TP rolls long I then ran strips o' maskin' tape LENGTHWISE from just beyond t' tip t' just aft/tailward o' t' nose-cone/fuselage joint). Blimey! Blimey! At t' tip, I cut the corners steeply and wrap around t' nose cone. I had t' run a few spiral wraps for support and t' maintain shape.
Nose Cone
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Shoulder |
Nose Cone/Fuselage |
As mentioned, t' buildin' and paintin' run together as t' paintin' be done before completely fittin' together t' parts.
Once I had t' shape roughed out, shiver me timbers, it be time t' fill. Arrr! Blimey! However, I wanted t' have a clean paint job with different colors for t' fuselage and t' tube fins. I felt that maskin' would be tough. Arrr! But if I painted them first, shiver me timbers, then I would be tryin' t' glue together painted surfaces. That didn't sound like it would be t' strong. Ahoy! On t' other hand, I KNEW exactly where all t' joints would be (I be usin' four tube fins, paired, on opposite sides o' t' fuselage. Well, blow me down! Since 6 tubes would fit perfectly, I just placed marks at 60 degrees, 120 degrees, shiver me timbers, shiver me timbers, 240 degrees, matey, and 300 degrees on t' fuselage. On t' tube fins, ya bilge rat, two marks each, matey, 60 degrees apart, would suffice. Begad! Blimey! For increased stability, I let 1/2 o' t' tube fins lag behind t' end o' t' fuselage (also thought would look cooler. Later durin' actual preparation o' t' rocket for launch I found it did make access t' t' engine mount awkward.) So marked on all t' tubes where t' joints should be. Avast, me proud beauty! I also marked where I wanted t' put t' launch lug.
I wanted t' "protect" t' joint areas from t' paint and sealer t' set up a stronger joint. Ya scallywag! On t' UE1 I had placed thin strips o' maskin' tape over these areas. I discovered t' maskin' tape broke down under t' sandin' process, shiver me timbers, shiver me timbers, so I tried Mylar tape strips, me hearties, 1/4 inch wide. Avast, me proud beauty! Blimey! I placed a "tail" over t' edge/lip o' each tube, and then wrapped t' very tip INSIDE t' tube. Ya scallywag! Begad! Turned out t' sandin' still wore off most o' t' tails, me bucko, me bucko, but t' tip piece wrapped inside be an adequate marker for removal o' t' tape later. Blimey! Each strip be 1/2 t' length o' a single tube.
It took five coats/sandings o' Elmer's filler t' get a good smooth surface over t' nose-cone maskin' tape. Avast, me proud beauty! Therefore regardin' "savin' money" as a reason t' make your own nose cone--Unless your time is worth less than 25 cents an hour, me hearties, you’re better off buyin' it from Tim. But since this WAS a themed rocket, it seemed worth it. (Although me lovely wife wasn't happy about t' pile o' filler dust on t' front porch!) I need three coats/sandin' t' fill t' DEEP VALLEYS o' t' toilet paper roll spirals anyway, arrr, (another reason t' use REAL body tubes.) I sealed t' tube fins (outside only) t' same way.
Note that since this is a rear-ejection model, it allowed me t' cover t' nose-cone/fuselage joint. While I be fillin' in t' maskin' tape defects and t' tube spirals, me bucko, it turns out I had enough filler t' cover t' external coupler. Blimey! In fact, arrr, by t' time I was done t' slight residual "bulge" be hardly notice-able. (Performance-minded rocketeers are probably shudderin' at t' added weight o' t' filler required t' accomplish THAT.)
When I was finished, I had a very nice fuselage with a smooth surface from tip t' tail, ya bilge rat, me hearties, shiver me timbers, except for t' "break" in t' external coupler where I planned t' put t' launch lug. Again, me hearties, had I been thinking, I would have filled this in too and put hidden t' lug in t' tube fin/fuselage joint. I believe t' absence o' a nose-cone/fuselage transition gives t' rocket a retro Buck Rogers look. O' course, ya bilge rat, I also believe in t' tooth fairy. Ahoy! Avast! Again, matey, I digress......
I knew that tryin' t' fill in t' INSIDE spirals o' t' tube fins be goin' t' be hopeless. I figured t' insides o' a spaceflight engine would probably look a little "charred", shiver me timbers, me bucko, so I planned on paintin' t' inside flat black and hoped that would hide t' defects.
Okay, matey, so paintin' now comes before actually completin' construction. Blimey! Ya scallywag! Before starting, I peeled back t' edges o' t' Mylar at t' distal edges o' t' tubes, me hearties, me hearties, shiver me timbers, t' make sure I could find them after paintin' (paintin' t' inside would obscure t' "tails" I had wrapped on t' inside o' t' tube.) T' hard part was FINDING t' edge. Avast! Many o' t' "tails" that I had thought would provide "handles" had been sandin' off durin' finishing. Avast, me proud beauty! Ya scallywag! But t' tips that I had wrapped on t' inside (unsealed) part o' t' tubes were still there. Begad! Blimey! Usin' them as guides, I used an Exacto knife t' peel back t' edges o' t' Mylar tape on t' OUTSIDE so I could find it after paintin' t' inside. Begad! I wrapped newspaper around t' OUTSIDE o' t' tube fins, tapin' it at t' edges/lips. Then I used flat black paint t' finish t' INSIDE o' t' tubes. Ahoy! I actually tried rolled up sandpaper t' reduce t' "nap" inside t' tube, ya bilge rat, but it didn't work very well. Primer would have helped, but I be havin' a struggle justifyin' tryin' t' prime t' INSIDE o' t' engines. Avast! Avast! Again, me hearties, I figured I was goin' for style, me hearties, nay performance, so I gave up on that part. Arrr! I sort o' liked t' internal "charred" look o' t' engines. Begad! As a prior Air Force guy, shiver me timbers, I noticed t' nozzles o' jet engines on t' flight-line often had blackened look, arrr, so I felt I was okay with it for space engines.
Color Scheme: All t' pictures o' t' PLANET Uranus showed it t' be a bluish color, ya bilge rat, so I figured I'd stay with this.
I primed t' fuselage with Krylon White Primer, three coats, with light sandin' betwixt coats. Ahoy! Begad! Blimey! This filled in t' few defects I had left after t' Filler. Ahoy! Blimey! I used Krylon True Blue for t' fuselage - I really like t' color this gave, arrr, matey, and I was happy with t' finish here.
After paintin' t' inside o' t' tube fins black, me hearties, I took off t' outer maskin' paper. I then rolled up paper INSIDE t' tubes t' mask t' insides. Ahoy! This allowed me t' "stack" t' tubes, shiver me timbers, which actually made paintin' t' outside easier. Blimey! I had run out o' primer, ya bilge rat, ya bilge rat, so I went directly t' paintin' t' outside o' t' tubes Blue Ocean Breeze. I did 3 coats, with a light sandin' betwixt coats. Well, blow me down! I liked this color as well. Although I hadn't thought it out ahead o' time, I remember t' three colors that were common for bathroom tiles in t' 60s--- pastel yellow, pastel pink, me hearties, and pastel blue. Begad! Blimey! This looked pretty close t' t' pastel blue, ya bilge rat, ya bilge rat, connectin' t' planetary and Toilet Paper theme.
Moment o' truth, me bucko, what would happen when I peeled off t' Mylar? Actually, I was quite pleased with t' sharp edges. Blimey! Pullin' t' tape off also raised some more "nap" off t' cardboard tubes, me bucko, exactly what I wanted t' "rough it" for gluing.
As I had expected, matey, ya bilge rat, matey, despite t' masking, thar was a little bleedin' o' black and blue (no pun intended) at t' edges o' t' tube fins. Blimey! Blimey! I used thin strips o' silver Mylar tape t' cover/accent t' edges here and at t' trailin' end o' t' fuselage. Aye aye! As a USAFA grad, t' silver and blue together got me right under t' old squadron patch, as me Dad, a retired AF Navigator/Bombardier says. Ahoy! Begad! I wrapped t' edges o' t' tape into t' inside o' t' tube. Blimey! Well, shiver me timbers, blow me down! Lookin' back, this gave t' edge a bit o' a rough look; I probably would just have put it on t' OUTSIDE only, just up t' t' edge.
Now that this be finished, time t' see how things fit together. Ya scallywag! Avast! I used medium CA t' glue 4 tubes into two tube-fin pairs, placin' t' glue along one o' t' "naked" strips previously covered by Mylar. Layin' t' tubes flat gave me a good alignment. I then matched up t' remainin' strips on each tube pair with t' strips on each side o' t' tail o' t' fuselage. Begad! They matched up pretty well, arrr, and t' medium CA gave me enough time t' make sure t' alignment be perfect. Well, blow me down! I got a pretty solid joint (as I later proved in flight, ya bilge rat, me hearties, but more on that later.) Fillets weren't needed, me hearties, and t' fit covered t' "naked" areas.
I pried t' Mylar tape out o' t' defect in t' external coupler. Begad! This left a rougher edge.I glued in t' launch lug.If I had t' do it over, ya bilge rat, matey, I would have pulled this off AFTER doin' t' filler step, ya bilge rat, but BEFORE painting, me bucko, t' get a better look.
Next question, where t' attach t' shock cord? If I attached it inside, it would get hit by t' ejection charge fairly directly, me bucko, and would also cause problem with slidin' out t' motor pod. Ya scallywag! Begad! Perhaps more importantly, if it came out t' tail, shiver me timbers, arrr, t' rocket would fall nose first. Begad! My launch site is about 3/4 grass, matey, 1/4 asphalt. Ya scallywag! Invariably t' better t' finish on t' rocket, ya bilge rat, t' more likely it will land on t' asphalt. Ahoy! Also, ya bilge rat, while t' cardboard/maskin' tape/Elmer's Finish nose cone was holdin' t' finish well, I could feel that it was still a little "soft" and didn't think it would hold up t' a hard impact. Arrr! Finally, I figured if I could get t' rocket t' descent in a horizontal position, t' rocket body itself would be addin' t' t' drag and slow it down.
With t' rocket painted, me bucko, me bucko, t' CG o' t' rocket body be right at t' region o' t' external coupler. Avast, me proud beauty! Well, me bucko, blow me down! I threaded a needle with me Keelhaul®©™ shock cord into t' tube just above t' coupler next t' t' launch lug, matey, arrr, and pull about two feet out t' after end o' t' fuselage. Ya scallywag! Begad! I then threaded a needle with t' ENDS o' a long loop o' dental floss through a hole just BELOW t' coupler and out t' aft end o' t' fuselage. Well, blow me down! I then threaded ANOTHER loop o' floss (loop 2) through this loop, and pulled loop 2 through t' hole and out t' tail, keepin' t' ENDS o' loop 2 outside fuselage. Begad! Begad! I then used loop 2 t' pull t' shock cord BACK into t' tail o' t' fuselage and back through t' hole below t' coupler (there probably is an easier way t' do this, but this is what I came up with.) I then tied a tight "loop" o' shock cord, matey, runnin' it just next t' t' launch lug, me bucko, leavin' about 1 1/2 feet o' Keelhaul®©™ loose. Begad! Yes, shiver me timbers, this loop DID run inside t' rocket body, when t' engine pod would slide in and out, matey, but t' cord be runnin' longitudinally and wouldn't obstruct/catch on t' pod. I did add a bit o' thin CA t' secure it.
Since I wasn't sure how well me hollow nose cone would hold up t' t' Estes engine ejection blast, I cut a bulkhead out o' foam board and place it inside t' body. Ahoy! It slid up t' t' "shoulder" that had been placed on t' front o' t' body tube. Avast, me proud beauty! Ejection blast would hit t' bulkhead, but nay t' "formed" shape inside o' t' nose cone. Aye aye! Instead o' gluin' it into place, I placed a length o' Keelhaul®©™ on this in case I needed t' pull it out later (such as t' add nose weight), and left that loose.
Engine Pod: I originally planned t' use a length o' BT20 as an engine mount AND pod. However, after buildin' it, shiver me timbers, shiver me timbers, I discovered I wanted more room for me parachute and streamer. I used a BT20 for an engine mount. I then wrapped t' end o' a BT5 with electrical tape until it just fit inside t' BT20. Ya scallywag! T' BT5 acted as BOTH an engine block AND a duct t' direct t' ejection force t' t' front o' t' body, me hearties, where it hit t' bulkhead. I used foamboard t' cut adapter rings for t' BT20 at t' tail and t' BT5 at t' front o' t' body. Begad! These were sanded t' slide loosely, shiver me timbers, ya bilge rat, but hopefully t' front one would be tight enough t' seal t' ejection charges away from t' chute and streamer. Ya scallywag! Blimey! Lookin' back, I probably should have used two adapter rings up front, ya bilge rat, as a little bit o' ejection charge snuck around t' front rin' and slightly charred t' streamer.
I had initially planned on a long white "simulated TP" streamer t' recover t' rocket (in keepin' with t' theme). Ahoy! However, early on it was clear that given t' weight o' t' rocket a streamer would never safely slow t' rocket AND t' engine pod. Begad! Also, matey, me hearties, again I knew t' nose cone was a little bit "soft" and wanted t' cushion t' landin' o' t' body as much as possible. Ahoy! Ahoy! My solution had two parts. Aye aye! Begad! First, allow t' engine pod t' completely separate from t' body o' t' rocket, so t' two descend separately. Avast, me proud beauty! This reduced t' weight o' t' body o' t' rocket (with t' soft cone). Begad! If I needed nose weight, I could add it t' t' front o' t' pod, rather than t' body. Ya scallywag! This is a NICE trick with aft ejection boost gliders, by t' way. Arrr! You can adjust your CG by addin' weight t' t' front o' t' ejection pod, without affectin' t' weight or CG o' t' glider itself. Begad! Then I could use me white streamer t' safely recover t' engine pod (which wasn't really very delicate and be nay that heavy), arrr, ya bilge rat, and a parachute t' recover t' body. T' shock cord for t' body was attached t' OUTSIDE o' t' fuselage at t' CG, thus t' body descended horizontally under t' chute.
I used two pieces o' white crepe paper t' create t' streamer for t' body tube. Well, blow me down! I attached them side by side with silver Mylar tape. Well, blow me down! Avast, me bucko, me proud beauty! Blimey! I then accordion folded this into squares t' simulate toilet paper sheets. Ahoy! Avast, me hearties, me proud beauty! Blimey! T' silver tape showed on one side, which I thought would be easy t' see (on t' off chance this bird flew outside me launch site-- yeah, right.) T' other side was straight white, which looked like, shiver me timbers, me bucko, well, toilet paper. While for t' real theme this would be "rolled" around t' engine pod "spindle", shiver me timbers, me experience is that this is unlikely t' "unroll" in flight durin' descent. Therefore I stayed with t' accordion fold. Begad! Begad! Blimey! I used a length 10 times width, accordin' t' Stine's book o' optimal streamer length, then added a couple o' inches t' give me space t' attach it t' t' BT5 section o' t' pod.
I used a couple o' thick rubber bands t' link t' parachute t' t' Keelhaul®©™ shock cord attached t' t' mid section o' t' exterior body o' t' rocket.
Note: Originally I used Tim Van Milligan's Model Rocket Design & Construction book t' make two semispherical parachutes, me bucko, then "ironed" t' two together side t' side. T' idea was t' create a parachute with a "cleft" down t' middle, ya bilge rat, t' so called "glute chute." (For those who have actually intentionally fallen out o' perfectly good aircraft, me bucko, me hearties, thar be a parachute malfunction called a "Mae West" that looks somewhat similar.) However, while t' parachute looked good, the "glute chute" didn't pack very tightly, and even reducin' t' engine pod diameter from BT20 t' BT5 didn't give me enough room t' actually use this. Begad! Begad! Blimey! I made an 8-line 12-inch chute out o' a green garbage bag (okay, was gettin' tired o' t' theme at this point.)
Moment o' truth arrived. Begad! Well, blow me down! Would this work?
First "gotcha" was t' prep. Blimey! T' overhangin' 4 tube fins may (or may not) look cool. Well, blow me down! Well, shiver me timbers, blow me down! Blimey! They do however obstruct access t' t' tail o' t' body. Avast, me proud beauty! This is bad enough when all you have t' do is stuff an engine in, ya bilge rat, but when you have t' shove in t' entire engine pod with t' accordion streamer AND t' parachute up t' rear, those overhangin' tubes REALLY get in t' way.
Anyway, seemed like a C6-3 engine would probably be a good start for this.
Loaded it up on a nearly windless sunny day. Ahoy! Blimey! Ya scallywag! Blimey! Blimey! Blimey! Crossed me fingers. Arrr! Blimey! Blimey! Blimey! Fired. Boost was arced t' t' left (not sure if this was due t' some uneven-ness o' t' fins.) Made it t' roughly 150 feet, at apogee was travelin' nearly horizontal. Ejection was at or near apogee. Ya scallywag! Ahoy!
Perfect separation o' pod and body. Ya scallywag! Streamer extended nicely and at 36 inches long, arrr, 3 inches wide, white and silver, matey, was quite visible. Blimey! Chute also opened well. Well, blow me down! Rocket be far away at this point, me bucko, but t' descent be either horizontal or slightly tail down (just what I wanted, t' protect that nose!) Pod and body landed about 100 yards from pad, about 10 yards apart, on t' grass. Begad! Absolutely no damage from t' fall. T' white streamer was very slightly singed.
Had I been smart, I would have counted me blessings and put t' rocket on t' shelf at this point. However, me bucko, I'm nay smart. Begad! I decided t' try it again. On flight two t' engine pod apparently caught on somethin' (may have been packed too tight.) Probably me combined two tubes were nay as smooth internally as a single standard store-bought tube would have been. Ahoy! Negative ejection. Avast! Lawn dart. Avast! Well, me bucko, blow me down! Nay sure any nose cone would have come thought this unscathed, arrr, but me (five coats o' filler, matey, multiple hours o' sanding, multiple coats o' paint - whimper whimper) nose cone accordioned. Nay fixable.
Pros:
Cons:
There's a discussion of this review in The Rocketry Forum.
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Hans "Chris" Michielssen (August 15, 2011)
Great review and "back" story of the rocket. (But, you didn't use the word probe once!)
Certainly a true scratch build. Anybody who forms a nose cone out of a body tube is okay by me.
thanks for the laugh and great build.