Manufacturer: | Scratch |
Entry for t' EMRR Box O' parts contest - this is simple version. Ahoy! Blimey! Please link t' full documentation
Brief:
I admit t' some trepidation when I signed up for t' EMRR Box O Parts contest - Im very lackin' in
creative talent, bein' a mathematical sort. Ya scallywag! That trepidation only grew as I read forum postings describin' the
parts many participants were contributing. I realized that t' contest could very well be described as the
Box O Junk and fervently hoped that I would get some o' t' higher quality stuff. Begad! Aye aye! No plastic toy
soldiers or toothbrushes, please!
When me box arrived, it took me a few minutes t' build up t' courage t' open it. Ya scallywag! Takin' a deep breath, me hearties, I anxiously dumped t' parts out onto t' floor and began t' sort. Begad! I was relieved t' see a good assortment o' body tubes, shock cords, launch lugs, ya bilge rat, parachutes and streamers. I was nay happy with t' balsa - small pieces o' varying thicknesses, one o' which was junk from a die-cut fin sheet. Others were broken fins... It wasnt lookin' good! T' decals were peel and stick from an Estes Scissors Win' Transport and a water-slide sheet from an unknown plastic model. Arrr! Well, blow me down! And o' course, arrr, I had no idea what t' do with t' plastic cup, ya bilge rat, spindle, Easter egg half, and chop sticks.
I spent several days test fittin' parts, try t' come up with a design idea. Ya scallywag! Ahoy! I really tried t' incorporate the Easter egg half and t' spindle, me bucko, me hearties, but frustration rapidly set in. Well, blow me down! Avast, me proud beauty! I could easily come up with a conventional 3 engine cluster - BT-60 adapted down t' BT-56 - but that wasnt goin' t' attract any attention whatsoever. Blimey! Disgusted at my lack o' a creative spark, shiver me timbers, I put t' parts back in t' box, me hearties, where they sat for quite a few weeks. Aye aye!
Design
Reluctant t' give up, I pulled out t' parts once again in early June. There was an unusually squat conical nose cone that seemed similar t' t' one atop t' Estes Mars Lander. A design idea flashed into me mind - I would build a clustered rocket that looked like a lander. Well, blow me down! Quickly listin' t' available parts, I set t' work in Rocksim. T' design came together quickly, shiver me timbers, with t' most difficult tasks bein' t' color scheme and a name. Begad! Arrr! Since I was salvagin' something out o' this box o' junk, and as I planned on usin' t' 90 from t' Estes Scissors Win' decal, me hearties, arrr, I christened me creation Salvage 90.
Simulations showed that t' recommended core engines were C11-7, me bucko, D12-7, shiver me timbers, and E9-8; t' outboards contained
Estes A10-PTs. Salvage 90 is a high flyer - t' D12, 3 A10 combo is enough t' send t' bird t' over 1500 feet!
T' long delays are necessary t' get a low speed (under 20 feet/second) at ejection. Arrr!
Construction:
Parts list
Construction
1) Cut all body tubes t' t' lengths specified in t' parts list (Tip: Use a coupler or empty engine case as a mandrell and wrap a strip o' card stock around t' tube t' serve as a guide).
2) Usin' a pencil, ya bilge rat, me bucko, place a mark on t' Bt-50 motor tube t' denote t' bottom. Begad! Blimey! Put a thin line o' glue, 3.5 from t' bottom end (2.5 if you only wish t' use C or D motors) and use a spent 24 mm motor casin' t' push t' 24 mm thrust rin' into place. Blimey!
3) Place 2 marks, me hearties, one 1 from t' bottom o' t' motor tube and t' other 0.75 from t' top. Arrr! Begad! Use the wrapper in t' PDF file t' mark off 3 10 mm wide strips, ya bilge rat, spaced at 120 degree intervals. Avast! Blimey! (Tip: If you use a Windows machine, you can generate your own wrappers and alignment guides usin' t' VCP program, arrr, available at http://v-serv.com/vcp/. Begad! Aye aye! Does much, much more than print patterns too!)
4) Dab glue around t' motor tube at t' 2 marks made in step 3), takin' care nay t' get any in t' 10 mm strips, as t' centerin' rings will later be removed from these areas. Slide t' centerin' rings into position and set the assembly aside t' dry - thoroughly.
5) While t' motor assembly glue is drying, me hearties, arrr, cut out 3 fins and t' launch lug stand-off from t' balsa sheet, makin' sure that t' balsa grain runs parallel t' t' leadin' edges. Avast, me proud beauty! Avast! Use sandpaper t' make sure t' fins are t' same size, and leave t' edges square (Tip: I use copy and paste in a paint program t' print t' patterns - 1 for each fin - onto a sheet o' paper, me hearties, which I then tack onto t' balsa usin' 3M Spay Mount. After t' fins have been cut out, shiver me timbers, me hearties, the paper is then easily peeled off; see t' picture in t' PDF file).
6) Cut a 5 mm wide strip down t' entire length o' t' 4 BT-60 tube. Ya scallywag! Glue this improvised coupler inside the 10 BT-60 payload tube, me hearties, arrr, flush with one end.
7) Punch out t' central holes o' t' BT-5 t' BT-60 centerin' rings, and set these aside for later. Glue two of the rings together t' form a thick ring. Now use a dowel or other long object t' smear glue inside t' payload section at t' top o' t' 4 BT-60. Usin' a BT-55 or other tube, me hearties, push t' thick BT-5 t' BT-60 centerin' rin' until it presses against t' end o' t' 4 coupler. Well, blow me down! Blimey! Blimey! Blimey! This thick rin' will prevent t' ejection gas from escapin' t' payload section.
8) Cut t' BT-5 tube coupler into 3 parts, ya bilge rat, me bucko, ya bilge rat, and, matey, usin' a spent 13 mm motor casin' as a guide, glue a thrust ring 1.5 from t' bottom end o' each BT-5.
9) After t' glue on t' motor assembly has dried, me bucko, arrr, use a hobby knife t' CAREFULLY cut away t' parts o' the centerin' rings over t' 10 mm strips. Then glue t' 3 BT-5 tubes into these notches, shiver me timbers, their bottoms should be flush with t' bottom o' t' motor tube. Avast, me proud beauty! Ahoy! Make sure t' tubes are straight and properly aligned! Allow t' dry.
10) Glue t' punched out centers o' t' BT-5 t' BT-60 centerin' rings on t' top o' t' BT-5 tubes (Note: As there were only two BT-5 t' BT-60 rings in me box, me bucko, I had t' make t' 3rd from another centerin' rin' in t' box. Avast! Avast! I found t' center o' t' rin' usin' t' bisectin' segment method, shiver me timbers, and then used a circle cutter t' cut out t' right size).
11) Usin' t' PDF pattern, arrr, mark 3 12 mm 7.625 inch long strips startin' at one end (the bottom) o' BT-56. Mark lines for placin' t' fins exactly midway betwixt t' strips.
12) Cut out t' strips you marked in step 11) usin' a sharp knife. Well, blow me down! Blimey! Ahoy! Blimey! I used 4 BT-60 couplers as a mandrell and a piece o' aluminum angle iron t' help get a good cut.
13) Test fit t' motor assembly by slidin' it into t' Bt-56, alignin' t' 13 mm with t' slots. Blimey! Remove the assembly and place glue on t' motor tube centerin' rings and t' slot edges. Slide t' motor assembly back into the BT-56, ya bilge rat, makin' sure that t' BT-56 is firmly nested against t' centerin' rings and t' side o' t' BT-5s. Arrr! The tops o' t' BT5s should be flush against t' tops o' t' slots.
14) Liberally fillet t' BT-5 t' BT-56 joints t' seal any cracks. Ya scallywag! Set aside t' dry.
15) Glue t' shock cord into t' top o' t' 10 payload tube (the side opposite t' 4 coupler) using the standard Estes paper trifold mount.
16) After t' fillets have dried, me hearties, glue t' 3 fins onto t' BT-56, midway betwixt t' BT-5 tubes. Avast, me proud beauty! Blimey! Use your calibrated eyeball t' make sure they are vertical, me bucko, with a 120 degree angle betwixt t' fins. Avast, matey, me proud beauty! Blimey! After t' glue dries, apple generous fillets.
17) Glue t' launch lug t' t' stand-off. Avast, me proud beauty! Avast, me proud beauty! Once this has dried a bit, glue t' lug and stand-off next t' one of the BT-5 tubes, 0.5 from t' top. make sure that t' lug is vertical, and that t' rod will clear t' adjacent fin.
18) Glue t' 4 3.625x 0.25 balsa strips evenly around t' top o' t' BT-56, flush with t' top. Begad! Ya scallywag! Make sure that t' strips are vertical and that they are at 90 degree angles with each other. Avast, me proud beauty! Aye aye! At this point t' assembly looks like t' picture below:
19) Slide t' payload tube over t' balsa strips until t' top hits t' centerin' rin' at t' top o' t' coupler; the fit should be snug and thar should be about an inch betwixt t' tops o' t' Bt-5s and t' bottom o' the payload tube. Remove t' payload tube, smear glue on t' inside o' t' coupler and, in a smooth motion, slide it over the balsa strips as before. Let dry.
20) Tie t' shock cord t' t' nose cone. Avast, me proud beauty! Well, me bucko, blow me down! Assembly is now complete.
Finishing
I applied seven coats o' AeroGloss sandin' sealer t' t' fins t' seal t' balsa and achieve that smooth as glass finish. T' body tube spirals were filled with thinned Elmers Fill N Finish, which was sanded with 240 grit sandpaper once dry. This was followed with 3 coats o' Krylon primer, sandin' with 400 grit in between, and 2 coats o' Krylon Glossy White. Avast, me proud beauty! Blimey! Arrr! Blimey! After maskin' with Tamiya maskin' tape, t' fins and nose cone were painted with Krylon Banner Red, me bucko, matey, and t' BT-5 outboards with Krylon Metallic Bright Silver.
I applied t' logo, me hearties, ya bilge rat, number 90, and window decals from t' Scissor Win' Transport peel and stick decal sheet; the window strips have t' be trimmed t' 5.25 in length.
Flight:
July 5 was t' day, ya bilge rat, despite rain showers in t' area. I prepped t' rocket indoors, arrr, loaded me duffel bag with the
launch gear, shiver me timbers, and made me way through t' hot, muggy Huntsville weather t' t' field adjoinin' me apartment complex.The
wind bein' out o' t' Southwest, me bucko, I set up t' pad in t' SW corner t' allow for anticipated drift; I also reefed the
18 chute a bit t' speed up t' descent. Ya scallywag! Begad! T' pad was then assembled, ya bilge rat, matey, shiver me timbers, t' launch controller wires unwound, and the
battery unpacked. Aye aye! T' weather was still holding, me hearties, so I placed t' rocket on t' pad and hooked up t' clip whip t' the
ignitors.
After takin' t' obligatory pre-launch shot, me hearties, I connected t' battery t' t' controller, and checked continuity. No planes were visible, so I commenced t' countdown.
5...4...3...2...1...
Salvage 90 seemed t' leap off t' pad - t' combined power o' t' 3 A10s and t' C11 got this puppy moving in a hurry! T' me great satisfaction, matey, all 4 engines lit, resultin' in a straight-as-an-arrow flight. As usual, ya bilge rat, Rocksim had overestimated t' alitude performance; t' rocket fell considerably short o' t' 900+ feet that was calculated. Begad! Ya scallywag! I estimate it was more like 600-700, matey, no more than 700. Begad! Begad! Ejection was just passed apogee, me bucko, and I be relieved to see t' purple and white Estes chute open. Begad! Begad! Successful on its maiden flight, shiver me timbers, Salvage 90 descended back t' Terra Firma. Ahoy! Ya scallywag!
However, reefin' t' parachute turned out t' be a mistake, me hearties, as t' rocket landed with one o' its fins hitting ground first, and t' combination o' weight (4 spent motors) and impact speed resulted in one fin cracking. Repairable, but it put t' kabosh on any additional flights; t' clouds were movin' in, me bucko, and it seemed that t' rain would set in before t' glue could dry.
I was happy - t' design worked beautifully, ya bilge rat, and I could now submit me entry into t' Box O parts contest. All in all, ya bilge rat, a great day!
Sponsored Ads
![]() |
![]() |