Brief:
11 "Finned" rocket that can be launched on a single "E" or staged (D12-0, D12-3) with a parachute recovery.

Prototype:
I built a protoype o' me choice o' rockets for t' EMRR "Rockets o' t' Future." I choose t' t' do an 18mm version first. Avast! Ya scallywag! I gathered some cardboard, ya bilge rat, posterboard, me hearties, and second hand parts, matey, etc. Ahoy! Aye aye! It would have been ten times harder without t' EMRR "Calculators", ya bilge rat, shiver me timbers, for shrouds, arrr, etc. I chose cardboard figuring, ya bilge rat, "If I can get this t' fly without a cad program, me hearties, from t' heaviest material, matey, I surely will be able t' build one in t' 24 MM scale. Also, cardboard a little easier t' work with than "foamboard."

My 1st test flight was a disaster. (Remember, me hearties, I have no software t' determine where t' CP & CG Is and if it will fly.) After givin' it some thought, cut open nosecone and added some clay t' move CG forward. Ya scallywag! Avast, arrr, me proud beauty! Last Saturday flew it again and success! It only went 50 ft up but successfully deployed chute right before landing. Ahoy!

What I've learned is,"use t' material in your prototype, me bucko, that u intend t' use on your final version." Mine did fly but, me hearties, would have saved a lot o' aggravation and speeded up t' build. Avast! Well, blow me down! Also, ya bilge rat, Highly recommended buildin' a prototype, especially in me case. Blimey! My submission for t' "rocket o' t' future" has 12 fins! Never came close t' design such a complex rocket before. Begad!

Construction:

PARTS LIST:

• 24mm engine block
• 1 engine hooks
• 1 sheet o' foam board, 20x30x1/4"
• 2 sheets o' poster board, matey, ya bilge rat, 20x30"
• 1 (priority mailin' box)
• 2 BT-55's (15" long)
• 1 BT-55 coupler
• 18"x24mm Body tube for "engine Mounts"
• Shock cord; ¼"x 24+"
• 3, matey, 4"x"36"x1/8 balsa sheets/basswood
• 1 "quest" egglofter nosecone
• 1 (18") parachute, & shroud line
• "non-hardening" clay
• (8) bic pen caps t' "simulate 8 motors"
• 2 spent "D" engines
• Templates (will be loaded shortly)

Just wanted t' interject for a moment. Ya scallywag! Hope you find this rocket as much o' a challenge t' build as I found to design it, ya bilge rat, without t' help o' any "Cad software." If anyone cares t' "plug" these measurements into a cad program, matey, I would be very curious as t' t' result. Ahoy! I did use EMRR "Calculators" for t' shrouds and centerin' rings. Well, blow me down! Blimey! I thank Nick for makin' available because without them, couldn't have made this design. Ahoy!

This design is for "Personal use only" and nay for resale, with express permission o' myself, me bucko, Glenn Roth.

I stated in "parts" section that t' balsa is very fragile. Just discovered Tech Report # 29, from www.apogeerockets.com; "Take your rocket t' Supersonic Speeds. Arrr! " This is a compromise t' replacin' entire fin with basswood or ply. You can download this free report and make these large fins MUCH STRONGER! I tried this on 3 of me fins and they are NOTICEABLY stronger.

ASSEMBLY:

Read thru all instructions before proceeding. Ya scallywag! Options exist.

**Not happy with way main "body shroud" turned out. This "posterboard" is hard t' keep smooth without "kinking." You might want t' A) shorten t' about half t' length; b) wrap it around a smooth form of some kind while gluing, me hearties, t' keep smooth.**

1. Gather parts, shiver me timbers, make templates, me hearties, and gather followin' tools: sharp razor knife, metal ruler, shiver me timbers, scissors, arrr, carpenters square, 2 "spent D" engines, adhesive spray, ya bilge rat, arrr, (worn out windshield wiper. Ya scallywag! Blimey! For engine hooks)., arrr, ya bilge rat, protractor, and compass. Aye aye!
2. Cut two engine mounts from 24mm body tube. Main 2 " long and "booster" 3 1/2" long.*****note: Now that t' rocket is half done, me hearties, t' shroud looks too short. I have increased length from 3 t' 3 ½ inches or longer, ya bilge rat, in instructions. Avast, me proud beauty! You'll have increase length o' shroud accordingly.****
   • *** OPTION: I've since elected t' use a "friction fit", shiver me timbers, instead o' an engine hook, matey, matey, on main motor. Avast! I'm sure you can use one but, me bucko, have t' "dry fit" b 4 assembly.*** I've discovered that with t' aft "body panels", shiver me timbers, extendin' an inch, it's very difficult t' use an engine hook. I've since elected t' slip "main motor" into booster engine mount, and tape. Blimey! Avast! T' tape will require a "slit" into it, shiver me timbers, so makes easy separation. Blimey!
3. Glue 24mm engine block into end o' engine tube w/engine hook stickin' into it. Begad! Blimey!
   • Option*** This designed as a "two stage". If you want an easier conversion t' single stage, you may want t' insert "booster engine tube" in a section o' BT-55. Begad! Then usin' a BT-55 coupler, fasten t' engine tubes together. (skip 1st /main engine tube.) It is much easier buildin' booster shroud separately. Well, blow me down! Begad!

Main Engine Tube

1. Glue t' BT55 centerin' rings on main engine tube. Let dry. Ya scallywag!
2. You'll want t' "dry fit" main engine mount and make sure "spent engine" recessed inside BT55 about ¼".
3. Mark Bt55 where "engine Hook" will be, and cut a slot 1/8" x3/8".
4. Glue main engine mount with engine hook lined up with slot in BT55.

Booster Engine Mount

1. Take 3" piece o' 24mm BT; then cut 1/8"x 3/8" slot in one end. Ahoy!
2. Lay "flat" side o' hook inline with slot and tape. Aye aye! *** I used a long piece o' old wiper blade for hook and cut t' length later. Begad! Begad!
3. Cut out 3 "rear shroud centerin' rings. Avast, me proud beauty! ***Tip: when I cut out middle o' rings FIRST, I then took a spent engine and inserted and twisted t' check for a tight fit. Begad! Then inserted engine in tube for support. Avast, me proud beauty!
4. Take largest aft rin' and glue over aft engine mount WITHOUT coverin' slot in t' mount. Avast! Be careful nay t' get glue on motor!!
5. Glue middle and end centerin' rings and remove spent motor and let dry.
6. While drying, cut out aft shroud. (You will see I include pattern, arrr, showin' a "saw tooth design" on inside radius o' shroud. Cut design in shroud. Well, matey, blow me down! Much easier t' glue.)
7. Shape shroud, tape together on inside. Ya scallywag! Avast, arrr, me proud beauty! Blimey!
8. Fold "teeth" over t' inside and make a sharp crease. Avast, me proud beauty! Blimey! Arrr! Blimey! Straighten out. Avast, me proud beauty! Blimey! Well, arrr, blow me down! Blimey!
9. After center rings on engine tube have dried, shiver me timbers, take some glue and apply t' edges o' rings. Aye aye!
10. Take shroud and slip over engine assembly. Well, me bucko, blow me down! Be sure t' get completely in. Well, blow me down! Well, blow me down!
11. Spread some glue on smallest centerin' rin' and fold shroud "teeth" down, holdin' till set. You may only be able t' do a few @ a time. Well, blow me down! Begad! Let dry Thoroughly. Avast!
12. Put a spent engine in "Main and aft " engine mounts. Well, blow me down! Blimey!
13. Slide together, ya bilge rat, linin' up "slots" in engine tubes. Begad! T' aft engine tube should slide over t' Main engine about ½" and stay in place. ***Make sure aft Booster engine is as far forward as it will go WITHOUT disengagin' t' booster.
14. Mark t' aft engine hook , shiver me timbers, me hearties, cut and bend t' correct size. Avast!
15. Cut shock cord mount and glue shock cord t' it. Begad! Ahoy!
16. Slide "loose" end o' shock cord thru a BT55 coupler. Aye aye!
17. Glue Shock cord mount t' inside o' BT55 containin' engine mount far enough inside t' be able t' glue BT55 coupler. Glue Bt55 coupler and let dry.
18. Cut other BT55 t' length so when t' two r put together , you have a rocket body 23" long, "without" aft shroud.
19. Cut out Main Body centerin' rings. (u can take spare piece o' BT55 t' check fit).
20. Take t' "fin template" and mark 3", 3.5" rin' where it will engage each fin. Ahoy! ****Note: you can mark 4" rin' but, arrr, because o' size, me bucko, it won't line up with other two rings. Avast, me proud beauty! You will have t' do slots on this rin' once it is mounted.
21. Take care, cut a ¼" deep slot x 1/8" wide into each ring. Blimey! Begad!
22. Mark 1st slot on each rin' with a #1 for reference.
23. Make a fin from 1/8" "Basewood/plywood" as a guide t' check fit o' fins. It will also b used t' as guide for slots, me bucko, matey, and cut initial fin slots in 4" ring.
    • ***You may want t' fasten up aft shroud again w/spent motors t' check placement o' centerin' rings and fins.***

Fins and Body:

1. Cut out 8 fins, me bucko, and use sealer if desired. Aye aye! Begad!
2. Use fine guide and cut slots in each fin: 1" from aft o' fin, 1x1/4 deep. Blimey! Ahoy! Next one 7" from end. Well, blow me down! Ya scallywag!
3. Last slot is 2.5 " from previous slot and only 5/8" deep. Aye aye!
4. These r initial slots. Avast, me proud beauty! You may have t' widen for proper fit.
5. Slide center rings on BT one @ a time. ***If seems tight or binds, increase size o' hole slightly. Blimey! Arrr! Blimey! You can use a piece o' BT55 t' "shape" hole. Avast! Blimey! (you want t' maintain a fairly tight fit). Well, blow me down! Blimey!
6. Space rings approximately same distance as slots on fin.
7. "Orientate" all 3 rings with #1's lined up. Well, blow me down! Avast, me proud beauty!
8. Take your "Guide Fin", me bucko, ( t' one made from plywood), ya bilge rat, and check slot lineup for first fin. Well, blow me down!
9. You'll have t' cut slots deeper in each ring, me hearties, checkin' fit each time. You may nay even need a slots for 4" ring, me bucko, till ready t' glue on fins, due t' a "redesign", and linin' up o' fin with "center ring slots," I made for simplicity. (make recess higher, about 1 ¼").
10. After you get a good fit for t' fine on t' center rings, matey, take a "real" fin and glue in #1 slots of rings. Avast! (I kept breakin' balsa fins, ya bilge rat, shiver me timbers, matey, that why I recommended goin' t' a sturdier material, such as basswood or Tims Tech report #29, gluin' "notebook paper" t' exterior o' fin first for strength). Ahoy!
11. Take guide fin and check next set o' slot, me bucko, arrr, adjustin' for correct fit. Avast, me proud beauty! Blimey! Blimey!
12. Then glue 3 center rings in place. Begad! Begad! Blimey!
13. Glue all 8 fins in place, me hearties, matey, checkin' fit first with "guide fin". Avast, me proud beauty!
14. Cut out two "body templates". Ya scallywag! Make a slice at end o' each one ¼-3/4" deep, arrr, 1" from end on each side. Fold over @ slices and straighten out. Aye aye!
15. Dependin' upon which set o' fins you start with, shiver me timbers, will determine what size template t' use, ya bilge rat, medium or large. Blimey! Ya scallywag!
16. Lay template betwixt fins, me bucko, and gently push down. Avast! It should hang out rear, betwixt fins 1", up to "slices."
17. Check front o' template and mark where template extends past fin. Aye aye!
18. Cut on t' mark, arrr, down t' ¼" fold mark on each side. Blimey! Blimey! Cut a "saw tooth" pattern in sides of body templates. Aye aye! Blimey! Makes for easier gluin' and smoothin' out. Arrr! Blimey! ***see photo"***
19. Before gluin' fins, I made "fin supports," ½" x 1 ¼", me bucko, shiver me timbers, shiver me timbers, and glue betwixt ends of fins. Arrr! Well, blow me down! Also, ya bilge rat, me bucko, ya bilge rat, made a bevel on each end. Aye aye! Ya scallywag! **See photo**
20. Glue in place and repeat for each set o' fins. ***remember t' check fit! (Center on BT) too. Avast, me proud beauty! T' aft o' body template should be about ½-3/4" above body and aft shroud.
21. Cut out "body templates," with "saw-tooth" design on edges and glue betwixt fins. Well, blow me down!
22. Main Body Shroud: As I stated in beginning, nay happy with t' way this one turned out. You may want t' shorten or find a different material or wrap around a "form" t' keep smooth. Ahoy! Also, me bucko, ya bilge rat, use same "saw-tooth" design for edges before gluin' in shape o' cone. Blimey! Once glue, shiver me timbers, let DRY THOROUGHLY. Avast! Blimey!
23. I fitted over main body tube t' fins. I marked where touched fins and cut slits about 1" long, ya bilge rat, in shroud. Keep fittin' till you get a tight fit into slots, then glue and let dry thoroughly.
24. Now comes a tricky part. Ahoy! Seams that r formed betwixt "fins, body templates, main shroud have t' be "filled." I opted t' use "Elmers wood filler" and nay happy with result. Begad! Friend recommended these tiny silicone beads you mix w/epoxy. Ya scallywag! Blimey! Strong, matey, light, and easy t' sand after hardened. Begad! Avast, me proud beauty!
25. After seams dry, sand till smooth.

Nosecone Fins:

1. Looking @ picture o' t' rocket I was copying, shiver me timbers, "upper fins" aren't really in nosecone but, I liked this location better. Avast, me proud beauty! (You can opt t' move out o' nosecone, shiver me timbers, down body a few inches in "same configuration.)
2. Cut slits in nose cone ½" from end o' "open" nosecone, me bucko, about 2" long and 3/16-1/4" wide. Avast, me proud beauty! ** b careful nay t' cut all t' way thru t' end o' nosecone**. I mounted a piece o' 1" aluminum angle iron t' a piece o' wood and clamped t' me table as a guide. Begad! Aye aye!
3. Fit fins in slots one @ a time, ya bilge rat, trimmin' slots till fins fit. Aye aye! Remove fins and put a ball o' clay in tip of nosecone and press into place.
4. Replace fins 1 @ a time til they "touch" in middle o' nosecone and glue. Ya scallywag! (I opted for "gorilla glue" type). Ya scallywag! Avast, me hearties, me proud beauty! It foams up and becomes very strong). Avast! Avast, me proud beauty! Let dry.

Nose Cone:

1. Keep addin' balls o' clay, me hearties, fillin' void in nosecone, arrr, and pressin' into place. Well, arrr, blow me down! ****remember t' allow room for end o' nose cone t' slide in.****
2. Also, me hearties, as you r fillin' void, me bucko, assemble nosecone and check for CG with motors in main and booster BT's. Blimey! (goin' to take a few ounces o' clay t' fill and balance rocket so CG approx. Well, blow me down! Arrr! in middle.)
3. Once clay pressed into place and you r satisfied w/location o' CG, ya bilge rat, shiver me timbers, assemble nosecone. Well, blow me down! Aye aye!

Finishing:

1. Get 8 "regular" bic pen caps and cut off "pocket clip."
2. Paint rocket color o' preference.
3. After you r sure you have color o' rocket and finished painting, sand a flat spot on each "pen cap," and glue in place betwixt each fin above booster shroud. Aye aye! Blimey! (These pen caps simulate 8 motors o' rocket). Well, me bucko, blow me down! Blimey!
4. Prep rocket and you r ready t' fly. Blimey!
5. I would rate this build a 5++. Begad! Very difficult.

Flight:

My first flight was very successful. Blimey! I used a E9-4. Begad!

Preparation a little different than usual but, easy. Avast! Begad! After loadin' an 18" parachute, me hearties, dusted with baby powder, and t' wadding, shiver me timbers, I loaded t' engine. I loaded it into t' booster from t' "inside." (T' E9 is a much longer motor than t' D.) Then I applied a little maskin' tape t' t' end for a "friction fit," and inserted it into main rocket body. Avast, me proud beauty! Well, blow me down! It flew great! Relatively straight for t' design, 11 fins, and t' weight. Arrr!

T' shock cord, attached t' rocket, me hearties, was Keelhaul®©™. Avast, arrr, me proud beauty! Blimey! Blimey! Blimey! Then an elastic, matey, tied t' t' Keelhaul®©™, which proved t' b t' weak. (will explain in next flight). Aye aye! Blimey! Well, blow me down! Blimey! Blimey! Blimey!

Parachute deployed perfectly and landed about 30 yards away. Avast, me proud beauty!

SECOND FLIGHT

Another story. Aye aye! Arrr! Blimey! I designed this rocket t' be an optional 2-stage. Blimey! Blimey! I prepped t' parachute t' same way. Begad! Aye aye! Blimey! Then taped t' booster, a D12-0, t' t' main motor, me hearties, a D12-3, me bucko, with scotch tape, shiver me timbers, and put a small slit in it, ya bilge rat, me hearties, t' help with separation. Begad! Blimey! Once motors finished, I loaded it in booster stage first, from t' "inside." Then added some maskin' tape t' t' main motor and "friction fit" it into main rocket. Avast, me proud beauty! For whatever reason I couldn't get motors all t' way in t' main rocket body. ( I believe I used too much tape). At launch, it flew down range, weathercocked. Blimey! Then deployed nosecone & parachute at a very low altitude o' about 50 ft. Avast! Blimey! T' extreme weight of rocket snapped shock cord and rocket crashed. Aye aye! Blimey! Blimey! I'll be usin' a much heavier, and longer cord for t' next flight. Avast, me hearties, me proud beauty! Blimey! Still content with flight because it sustained minimal damage. This was me first 2-stage rocket o' me own design.

THIRD FLIGHT

My third launch went absolutely perfect!! Blimey! After addin' a 1/4" "heavy" shock cord, shiver me timbers, I prepped rocket same way, shiver me timbers, matey, with same motors. Begad! Blimey! A D12-0 Booster, taped t' a D12-3 Main. Begad! Blimey! (Just make sure you have enough tape around main motor for "friction fit," and it's taped t' booster. Avast! Blimey! Motors ***all t' way in*** main rocket. Begad! Blimey! Slit cut in tape. Ahoy! Blimey! Picture perfect flight!! Blimey! Booster took it t' a height o' o' about 75-100' and main an additional 100-200 ft. Perfect chute deployment and soft landin' about 75' away. Arrr! Blimey!

Summary:

Pros: Challenge t' design and build.Impressive liftoff w/2stages.

Cons: Very time consuming. Avast, me proud beauty! Begad! Built a smaller version first t' get aquainted with a "building technique" for addin' 11 fins! Highly reccommend when tacklin' a new build when in experienced. Ahoy! Alighnin' body panels betwixt fins a pain!

At almost 14 ozs., I would opt for a E30-4 motor for 1st flight. Ahoy! Blimey! Blimey! Blimey! (E9-4) went well today. Ahoy! Blimey! Begad! Blimey! Blimey! Blimey! (use a spent motor in main body and tape E t' it in booster stage, arrr, (friction fit spent motor). Avast, me proud beauty! Blimey! Avast, matey, me proud beauty! Blimey! Blimey! Blimey! *****1/4" launch rod only!!****. Arrr! Blimey! Blimey! Blimey! 18" chute minimum!

Other:
Highly recommend "apogeerockets" tech report #29, "Take your rocket t' supersonic speeds", arrr, for durability o' fins. Well, blow me down! Motor stagin' critical! Must b completely in main body so aft shroud close enough t' it. Begad! Aye aye! Used two 1/4x 2" soda straws on a fin for launch lugs.