Brief:
11 "Finned" rocket that can be launched on a single "E" or staged (D12-0, me bucko, 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. I gathered some cardboard, posterboard, me bucko, and second hand parts, etc. Ya scallywag! Blimey! Arrr! Blimey! It would have been ten times harder without t' EMRR "Calculators", for shrouds, me bucko, me bucko, etc. Well, blow me down! Blimey! I chose cardboard figuring, "If I can get this t' fly without a cad program, from t' heaviest material, I surely will be able t' build one in t' 24 MM scale. Well, blow me down! Blimey! Also, cardboard a little easier t' work with than "foamboard."

My 1st test flight was a disaster. Begad! (Remember, I have no software t' determine where t' CP & CG Is and if it will fly.) After givin' it some thought, shiver me timbers, cut open nosecone and added some clay t' move CG forward. Well, blow me down! Last Saturday flew it again and success! It only went 50 ft up but successfully deployed chute right before landing. Aye aye!

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

Construction:

PARTS LIST:

• 24mm engine block
• 1 engine hooks
• 1 sheet o' foam board, matey, me hearties, me hearties, 20x30x1/4"
• 2 sheets o' poster board, 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, 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. Avast! Hope you find this rocket as much o' a challenge t' build as I found to design it, matey, without t' help o' any "Cad software." If anyone cares t' "plug" these measurements into a cad program, I would be very curious as t' t' result. Aye aye! I did use EMRR "Calculators" for t' shrouds and centerin' rings. I thank Nick for makin' available because without them, couldn't have made this design.

This design is for "Personal use only" and nay for resale, with express permission o' myself, ya bilge rat, 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. " This is a compromise t' replacin' entire fin with basswood or ply. Avast! Ya scallywag! 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. Options exist. Well, blow me down!

**Not happy with way main "body shroud" turned out. Avast! Begad! Blimey! 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, shiver me timbers, t' keep smooth.**

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

Main Engine Tube

1. Glue t' BT55 centerin' rings on main engine tube. Begad! Avast! Let dry. Avast, ya bilge rat, me proud beauty!
2. You'll want t' "dry fit" main engine mount and make sure "spent engine" recessed inside BT55 about ¼". Blimey! Blimey!
3. Mark Bt55 where "engine Hook" will be, shiver me timbers, and cut a slot 1/8" x3/8". Blimey!
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. Aye aye! Arrr!
2. Lay "flat" side o' hook inline with slot and tape. *** I used a long piece o' old wiper blade for hook and cut t' length later.
3. Cut out 3 "rear shroud centerin' rings. Blimey! ***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. Well, blow me down! Well, blow me down! Blimey! Then inserted engine in tube for support. Arrr! Blimey!
4. Take largest aft rin' and glue over aft engine mount WITHOUT coverin' slot in t' mount. Ya scallywag! Be careful nay t' get glue on motor!!
5. Glue middle and end centerin' rings and remove spent motor and let dry. Begad!
6. While drying, ya bilge rat, ya bilge rat, cut out aft shroud. Blimey! (You will see I include pattern, arrr, matey, showin' a "saw tooth design" on inside radius o' shroud. Arrr! Cut design in shroud. Avast, me proud beauty! Arrr! Much easier t' glue.)
7. Shape shroud, tape together on inside.
8. Fold "teeth" over t' inside and make a sharp crease. Ya scallywag! Ahoy! Straighten out. Aye aye! Ya scallywag!
9. After center rings on engine tube have dried, take some glue and apply t' edges o' rings. Arrr!
10. Take shroud and slip over engine assembly. Avast! Be sure t' get completely in.
11. Spread some glue on smallest centerin' rin' and fold shroud "teeth" down, shiver me timbers, holdin' till set. You may only be able t' do a few @ a time. Avast! Let dry Thoroughly. Avast!
12. Put a spent engine in "Main and aft " engine mounts. Arrr! Blimey! Blimey!
13. Slide together, matey, me hearties, me bucko, linin' up "slots" in engine tubes. Well, blow me down! T' aft engine tube should slide over t' Main engine about ½" and stay in place. Begad! ***Make sure aft Booster engine is as far forward as it will go WITHOUT disengagin' t' booster. Ahoy!
14. Mark t' aft engine hook , cut and bend t' correct size. Arrr! Blimey!
15. Cut shock cord mount and glue shock cord t' it. Ya scallywag! Ahoy! Blimey!
16. Slide "loose" end o' shock cord thru a BT55 coupler. Ya scallywag!
17. Glue Shock cord mount t' inside o' BT55 containin' engine mount far enough inside t' be able t' glue BT55 coupler. Blimey! Glue Bt55 coupler and let dry. Avast, me proud beauty! Arrr!
18. Cut other BT55 t' length so when t' two r put together , you have a rocket body 23" long, "without" aft shroud. Ya scallywag!
19. Cut out Main Body centerin' rings. Ahoy! (u can take spare piece o' BT55 t' check fit). Arrr!
20. Take t' "fin template" and mark 3", 3.5" rin' where it will engage each fin. Blimey! Avast! ****Note: you can mark 4" rin' but, because o' size, it won't line up with other two rings. You will have t' do slots on this rin' once it is mounted. Arrr!
21. Take care, cut a ¼" deep slot x 1/8" wide into each ring.
22. Mark 1st slot on each rin' with a #1 for reference. Ya scallywag! Ahoy! Blimey!
23. Make a fin from 1/8" "Basewood/plywood" as a guide t' check fit o' fins. Begad! It will also b used t' as guide for slots, 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, and use sealer if desired. Blimey! Blimey!
2. Use fine guide and cut slots in each fin: 1" from aft o' fin, 1x1/4 deep. Avast! Next one 7" from end. Avast, me proud beauty! Begad!
3. Last slot is 2.5 " from previous slot and only 5/8" deep. Avast, me proud beauty!
4. These r initial slots. Arrr! You may have t' widen for proper fit. Blimey!
5. Slide center rings on BT one @ a time. Begad! Blimey! ***If seems tight or binds, increase size o' hole slightly. Begad! Blimey! You can use a piece o' BT55 t' "shape" hole. (you want t' maintain a fairly tight fit). Ya scallywag! Blimey!
6. Space rings approximately same distance as slots on fin. Ya scallywag! Aye aye!
7. "Orientate" all 3 rings with #1's lined up.
8. Take your "Guide Fin", ( t' one made from plywood), and check slot lineup for first fin.
9. You'll have t' cut slots deeper in each ring, checkin' fit each time. Avast! Blimey! You may nay even need a slots for 4" ring, till ready t' glue on fins, shiver me timbers, due t' a "redesign", ya bilge rat, and linin' up o' fin with "center ring slots," I made for simplicity. Avast! Blimey! Begad! Blimey! (make recess higher, me hearties, about 1 ¼").
10. After you get a good fit for t' fine on t' center rings, take a "real" fin and glue in #1 slots of rings. (I kept breakin' balsa fins, shiver me timbers, that why I recommended goin' t' a sturdier material, ya bilge rat, such as basswood or Tims Tech report #29, gluin' "notebook paper" t' exterior o' fin first for strength).
11. Take guide fin and check next set o' slot, adjustin' for correct fit. Avast!
12. Then glue 3 center rings in place. Aye aye! Ahoy!
13. Glue all 8 fins in place, me bucko, checkin' fit first with "guide fin".
14. Cut out two "body templates". Blimey! Make a slice at end o' each one ¼-3/4" deep, 1" from end on each side. Fold over @ slices and straighten out. Aye aye!
15. Dependin' upon which set o' fins you start with, me bucko, will determine what size template t' use, me hearties, ya bilge rat, medium or large.
16. Lay template betwixt fins, matey, and gently push down. Well, blow me down! Ahoy! It should hang out rear, betwixt fins 1", ya bilge rat, arrr, up to "slices."
17. Check front o' template and mark where template extends past fin. Begad!
18. Cut on t' mark, me bucko, me hearties, down t' ¼" fold mark on each side. Cut a "saw tooth" pattern in sides of body templates. Avast! Makes for easier gluin' and smoothin' out. Blimey! ***see photo"***
19. Before gluin' fins, I made "fin supports," ½" x 1 ¼", and glue betwixt ends of fins. Well, blow me down! Also, made a bevel on each end. Ahoy! Begad! **See photo**
20. Glue in place and repeat for each set o' fins. Well, blow me down! ***remember t' check fit! (Center on BT) too. Blimey! Well, me hearties, blow me down! 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.
22. Main Body Shroud: As I stated in beginning, nay happy with t' way this one turned out. Begad! You may want t' shorten or find a different material or wrap around a "form" t' keep smooth. Begad! Also, use same "saw-tooth" design for edges before gluin' in shape o' cone. Once glue, shiver me timbers, arrr, let DRY THOROUGHLY. Avast! Avast, me proud beauty!
23. I fitted over main body tube t' fins. Avast! Avast, ya bilge rat, me proud beauty! I marked where touched fins and cut slits about 1" long, shiver me timbers, in shroud. Keep fittin' till you get a tight fit into slots, ya bilge rat, then glue and let dry thoroughly. Avast!
24. Now comes a tricky part. Arrr! Blimey! Seams that r formed betwixt "fins, body templates, matey, main shroud have t' be "filled." I opted t' use "Elmers wood filler" and nay happy with result. Arrr! Well, arrr, blow me down! Blimey! Friend recommended these tiny silicone beads you mix w/epoxy. Strong, me bucko, light, and easy t' sand after hardened. Ahoy! Arrr! Blimey!
25. After seams dry, sand till smooth. Ya scallywag!

Nosecone Fins:

1. Looking @ picture o' t' rocket I was copying, "upper fins" aren't really in nosecone but, me hearties, matey, I liked this location better. Begad! (You can opt t' move out o' nosecone, down body a few inches in "same configuration.)
2. Cut slits in nose cone ½" from end o' "open" nosecone, about 2" long and 3/16-1/4" wide. ** 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. Aye aye!
3. Fit fins in slots one @ a time, shiver me timbers, trimmin' slots till fins fit. Arrr! Blimey! Remove fins and put a ball o' clay in tip of nosecone and press into place. Arrr! Blimey!
4. Replace fins 1 @ a time til they "touch" in middle o' nosecone and glue. (I opted for "gorilla glue" type). Aye aye! Well, blow me down! It foams up and becomes very strong). Ahoy! Aye aye! Let dry. Begad! Blimey!

Nose Cone:

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

Finishing:

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

Flight:

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

Preparation a little different than usual but, easy. After loadin' an 18" parachute, dusted with baby powder, and t' wadding, arrr, I loaded t' engine. Arrr! Well, blow me down! 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! It flew great! Relatively straight for t' design, me hearties, 11 fins, and t' weight. Begad!

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

Parachute deployed perfectly and landed about 30 yards away. Begad! Begad!

SECOND FLIGHT

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

Summary:

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

Cons: Very time consuming. Well, blow me down! Avast, me proud beauty! 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. Avast, me proud beauty! Alighnin' body panels betwixt fins a pain!

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

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