Brief:
3 stage cone rocket, 3 x 24mm first stage cluster, me hearties, 18mm second stage, arrr, 13mm sustainer, and aerobrake recovery.
Some time ago, Art Applewhite gave me one o' his 13mm Qubit rocket kits at an Alamo Rocketeers launch. Begad! It has worked great ever since and while t' "saucers" don't exactly appeal t' me aesthetically, me bucko, they have found their place in me grand scheme o' thin' because t' field I usually fly in is small. Aye aye! That makes clusters and staged rockets problematic...except for this one. Blimey! It is tailor made for me field.
Construction:
T' basic material consist o' foamboard, matey, matey, cardstock and that's about it. I "cheated" and used some BT-50 for t' first stage motor tubes.
This one turned out t' be harder than I expected right from t' beginning. Begad! Blimey! Begad! Blimey! Art Applewhite provides a .PDF o' t' templates at his website. Avast! Blimey! So far, so good. When really studyin' t' thin' though, ya bilge rat, I realized several things. Avast, me proud beauty! Blimey! First, thar are no instructions. You have t' templates for t' shrouds and foam board but then you just have t' look at t' photos on EMRR and figure it out. Ya scallywag! Blimey! Second, nay all o' t' drawings in t' PDF are full scale. Some are and its just a matter o' printin' them out on t' proper cardstock, but others are produced at 50%.
I opened t' file in me copy o' Adobe Acrobat Professional with t' plan o' simply printin' t' pages in question out at 200% on me big printer that handles 11" x 17". Ya scallywag! That produced two more problems. Acrobat only gives "full size" and "scale t' fit". Ya scallywag! Ya scallywag! I could nay generate 200% pages directly so I fell back on plan B.
Art thoughtfully provides t' radii needed for t' larger shrouds. Begad! Since I am a lousy manual draftsman, shiver me timbers, I started an Autocad file and was smartly able t' reproduce t' needed templates in a DWG file. Well, blow me down! Then it was just a simple matter o' printin' it out. Avast, me proud beauty! Well, blow me down! That's when I learned o' t' second problem with me approach. Avast, me proud beauty! T' largest o' t' needed shrouds was just a touch bigger than would fit on 11" x 17". I had t' print it in two parts with some match lines and hope I got it right.
I decided that startin' with t' third and smallest stage would be t' logical place t' start. Blimey! Begad! Blimey! I be able t' cut out t' shroud, shiver me timbers, motor mount, shiver me timbers, and aft bulkhead without any problem. Well, matey, blow me down! Blimey! T' stock I used be a bit stiff, but I still had little problem formin' t' cone. Aye aye! Blimey! Blimey! T' aft bulkhead be a bit more finicky and I decided that it would be best t' make t' motor mount t' makes sure everythin' fit. That seemed simple enough. Well, blow me down! Blimey! Blimey! I just had t' roll t' stock for t' mount into a tube, and I assumed, shiver me timbers, me bucko, glue along t' appropriate line t' form a tube. Ya scallywag! Blimey! I rolled t' tube and somethin' looked wrong. Aye aye! Blimey! When t' lines matched up, t' hole looked too small so I grabbed a spent 13mm casin' and sure enough, matey, arrr, don't trust t' match line. With that in mind, shiver me timbers, I rolled t' motor mount around t' casin' and glued it together. Arrr! Now all I had t' do was wrestle these three components together so that t' launch lug holes lined up. I managed t' do so...eventually. Blimey! Ahoy! Blimey! With that, t' upper stage be done.
T' next thin' I decided I had better get done be t' application o' t' templates I had produced with Auto CAD onto t' poster board. Begad! I was nay happy with t' poster board I found at Wal-Mart. Avast! Avast, me proud beauty! It seems much lighter than t' poster board I remember in school. Begad! Since I had made t' upper shroud with some glossy paper analogous t' that used in rockets like "T' Point" and "Vulcan", I went t' me local paper distributor t' see if I could get it in large sizes. Arrr! I was in luck. Begad! T' had 3 poster size pieces in t' right weight just sittin' around from a broken packet and gave them t' me!
With t' poster board and templates in hand, shiver me timbers, matey, I joined them together with 3M's 77 adhesive and set it aside t' dry. Ya scallywag! It was time t' work on t' 2nd stage.
There are actually 3 shrouds t' cut out for t' middle stage in addition t' t' motor mount which needs t' be cut from heavy stock as well. Rememberin' t' problem with t' upper stage, I used a spent 18mm casin' t' test t' match line. Ya scallywag! In this case, me bucko, it worked perfectly. Avast! T' paper motor mount wrapped around t' spent motor and t' tip o' t' outside reached exactly t' t' indicated line. Avast, me proud beauty! A little white glue set it up and allowed me t' get t' work on t' body.
T' body consisted o' 3 shrouds. Ahoy! I will refer t' them as t' outer (the part you see), t' upper (fits in t' interior near t' top) and t' lower (forms an aft bulkhead). Avast, matey, me proud beauty! I cut t' upper and t' lower out with a razor cutlass without any problem. Begad! Arrr! T' upper involves no creasin' and was easily formed. Well, arrr, blow me down! I did t' formin' around t' motor mount t' make sure t' fit was right and then glued t' tab.
T' lower shroud needed t' be creased along 2 arcs. I used a ballpoint pen and pressed down heavily along t' dashed lines. Avast! Well, me hearties, blow me down! Blimey! I found that after doin' so, me hearties, t' shroud was easily bent into t' proper position. Begad! Blimey! I again formed it around t' motor mount. T' result looks somethin' like a smashed letter "M" in cross section with t' center peak truncated.
T' outer shroud was cut from t' poster board I had gotten for free because it be too big for tabloid sized paper. Avast! I had glued t' template on and allowed it t' dry. Avast, me bucko, me proud beauty! It cut out easily and was again creased with a ballpoint. Avast, me proud beauty! It too bent into shape easily usin' t' motor mount as a guide. Avast, me proud beauty! Assemblin' t' 3 shrouds together though be less easy.
My problem be gettin' t' motor mount through all three pieces and then gettin' them t' line up right with t' launch lug holes. Begad! Ya scallywag! I used a short piece o' 1/8" rod for alignment along with t' motor mount. I found that fits which had been "good enough" were no longer good enough. T' trouble seemed t' be t' evenness o' t' central core through which t' motor mount was t' slide. Some "flashing" was in t' way. Begad! After an interminable exercise with t' razor knife, arrr, I used some 120 grit sandpaper t' smooth things out. Avast, me proud beauty! Aye aye! After that, t' mount slid in much more easily. Arrr! Then it was a matter o' gettin' everythin' aligned and applyin' t' glue.
T' motor mounts for t' first stage were much like that o' t' second. Avast, me proud beauty! I used a spent 24mm casin' and wrapped t' cardstock around it. Begad! Avast, me proud beauty! Like t' 18mm mount, I found that t' match lines worked perfectly.
T' shroud for t' first stage be also easy. Begad! It be simply a matter o' cuttin' it out since thar be only one and then gluin' along t' line. Arrr! Instead o' usin' interior shrouds for support, this stage uses foamboard.
T' templates for t' foamboard had already been applied. Blimey! I used a fresh blade on t' razor and cut around t' outer edge. Aye aye! T' templates also have a circle markin' t' inner edge. Avast, ya bilge rat, me proud beauty! T' foam has t' be cut at an angle t' accommodate t' cone shape o' t' rocket. Arrr! I found that cuttin' along t' outer line as a cylinder worked best. When t' outer profile was completely formed, I then took t' razor cutlass and shaved around t' edge t' put in t' proper bevel.
T' upper bulkhead slid into place easily. Ya scallywag! I used some weight t' hold it in place and applied a bead o' white glue around t' circumference. Blimey! Aye aye! When that was dry, matey, shiver me timbers, I inverted t' stage and put a bead around t' forward edge as well.
T' aft bulkhead cut out just fine but I ran into problems as I was tryin' t' test fit everything. Ahoy! T' motor tubes were a tight fit, me hearties, both in t' bulkhead and around t' motors. Begad! Arrr! I decided at this stage t' substitute 24mm body tubes for t' paper tubes.
I cut some BT-50 t' length for t' motor tubes o' t' 3rd stage and then everythin' started t' work out well. Blimey! Arrr! I glued them together in parallel, matey, and when dry, I test fitted them. Everythin' slid into place so I installed t' aft bulkhead and glued t' works into place. Arrr! Avast, me hearties, me proud beauty! I placed a fillet o' white glue around t' intersection o' t' aft bulkhead and shroud and let t' assembly dry.
PROs: nay too difficult for a 3-stage cluster
CONs: makin' everythin' keep its shape while workin' with it
Finishing:
I did nay like t' shroud overlap so I decided t' try t' minimize it by usin' Elmer's Fill ‘n' Seal t' fair out t' transitions. Ya scallywag! Arrr! I applied t' stuff and then sanded it down. Ahoy! It did improve things, however, I did a rushed job o' it in order t' be ready for a club launch. It could have been much better.
Not bein' very original when it comes t' artwork, I painted t' first stage red, t' second stage a brighter red and t' third stage orange. That too could have looked better. Begad! It was time t' see how this beast works.
Flight and Recovery:
On Art's advice, shiver me timbers, matey, I started modestly with just t' 2 stage version. Begad! I put a C6-0 in t' booster and an A10-PT in t' sustainer. Aye aye! Arrr! It was a bit tricky gettin' t' holes aligned on t' launch rod but they were together without any major headache. Well, blow me down! Even if it had been a major headache, all would have been forgiven after t' launch. Begad! Ya scallywag! It was great.
It went straight up, spinnin' unexpectedly, and then staged perfectly. Both sections recovered without a scratch. Well, blow me down! Aye aye! There was just some minor scorchin' on t' bottom o' t' upper stage and that be expected. Ahoy! Now it was time t' try t' full stack!
T' outboard motors were Estes D12-Ps. Avast! Arrr! T' central motor be a D12-0. Ahoy! Avast, me proud beauty! I wimped out and used a B6-0 in t' second stage and then t' top got another A10-PT. Arrr! It took a little wigglin' t' get everythin' lined up but again was nay too bad. Blimey! Well, blow me down! Again, almost anythin' would have been forgiven after launch.
Upon first pressin' t' button, ya bilge rat, matey, nothin' happened. Ahoy! I waited a little bit and then check things out only t' find that one o' t' clips from me whip be grounded out on t' rod. Blimey! I fixed that and tried again.
WHOOOOOOSH! It went off like a dream. Well, blow me down! Begad! It weathercocked a little bit but everythin' seemed t' work perfectly. I remember bein' bitterly disappointed that I wimped out with t' B6-0 and wishin' that I had used a C6-0 instead but t' B performed as it was supposed t' and they all come down in bounds.
A quick check showed that all motors had ignited. Ya scallywag! There was a little bit o' tearin' in t' first stage but that was o' t' paper I had printed t' pattern on. T' cardstock was unaffected.
PROs: It worked, ya bilge rat, it landed in bounds
CONs: None
Summary:
PROs: 3-stager able t' be flown from small fields, matey, cluster able t' be flown from small fields, me hearties, it works
CONs: non-traditional shape, me hearties, me hearties, burns up motors quickly