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. I gathered some cardboard, posterboard, matey, arrr, and second hand parts, etc. Ya scallywag! Aye aye! Blimey! It would have been ten times harder without t' EMRR "Calculators", for shrouds, me bucko, ya bilge rat, etc. Begad! Blimey! I chose cardboard figuring, "If I can get this t' fly without a cad program, from t' heaviest material, shiver me timbers, I surely will be able t' build one in t' 24 MM scale. Arrr! Blimey! Also, cardboard a little easier t' work with than "foamboard."

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

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

Construction:

PARTS LIST:

• 24mm engine block
• 1 engine hooks
• 1 sheet o' foam board, arrr, 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, me bucko, 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. Ahoy! Hope you find this rocket as much o' a challenge t' build as I found to design it, 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. Ahoy! I did use EMRR "Calculators" for t' shrouds and centerin' rings. Aye aye! I thank Nick for makin' available because without them, matey, arrr, couldn't have made this design.

This design is for "Personal use only" and nay for resale, shiver me timbers, with express permission o' myself, Glenn Roth. Ahoy! Avast!

I stated in "parts" section that t' balsa is very fragile. Begad! Ya scallywag! Just discovered Tech Report # 29, me hearties, from www.apogeerockets.com; "Take your rocket t' Supersonic Speeds. Begad! " This is a compromise t' replacin' entire fin with basswood or ply. Aye aye! Aye aye! 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. Avast! Avast, me proud beauty!

**Not happy with way main "body shroud" turned out. Avast, me proud beauty! 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, ya bilge rat, t' keep smooth.**

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

Main Engine Tube

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

Booster Engine Mount

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

Nosecone Fins:

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

Nose Cone:

1. Keep addin' balls o' clay, me hearties, fillin' void in nosecone, me bucko, and pressin' into place. Begad! ****remember t' allow room for end o' nose cone t' slide in.****
2. Also, as you r fillin' void, assemble nosecone and check for CG with motors in main and booster BT's. (goin' to take a few ounces o' clay t' fill and balance rocket so CG approx. Begad! 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. Begad!
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. (These pen caps simulate 8 motors o' rocket). Well, blow me down! Blimey! Blimey! Blimey!
4. Prep rocket and you r ready t' fly. Avast!
5. I would rate this build a 5++. Begad! Very difficult. Arrr! Aye aye!

Flight:

My first flight be very successful. Blimey! Blimey! I used a E9-4. Blimey! Ya scallywag! Blimey!

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

T' shock cord, attached t' rocket, me hearties, was Keelhaul®©™. Then an elastic, tied t' t' Keelhaul®©™, shiver me timbers, which proved t' b t' weak. (will explain in next flight).

Parachute deployed perfectly and landed about 30 yards away.

SECOND FLIGHT

Another story. Begad! Blimey! I designed this rocket t' be an optional 2-stage. Well, blow me down! Begad! Blimey! I prepped t' parachute t' same way. Ahoy! Blimey! Then taped t' booster, ya bilge rat, a D12-0, t' t' main motor, ya bilge rat, a D12-3, me bucko, me bucko, with scotch tape, arrr, and put a small slit in it, t' help with separation. Once motors finished, me hearties, I loaded it in booster stage first, ya bilge rat, me bucko, me bucko, from t' "inside." Then added some maskin' tape t' t' main motor and "friction fit" it into main rocket. For whatever reason I couldn't get motors all t' way in t' main rocket body. Aye aye! ( I believe I used too much tape). Avast, me proud beauty! Blimey! At launch, me hearties, me hearties, it flew down range, weathercocked. Then deployed nosecone & parachute at a very low altitude o' about 50 ft. Begad! Blimey! T' extreme weight of rocket snapped shock cord and rocket crashed. Begad! I'll be usin' a much heavier, matey, and longer cord for t' next flight. Begad! Begad! 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!! After addin' a 1/4" "heavy" shock cord, I prepped rocket same way, with same motors. A D12-0 Booster, taped t' a D12-3 Main. (Just make sure you have enough tape around main motor for "friction fit," and it's taped t' booster. Aye aye! Ya scallywag! Motors ***all t' way in*** main rocket. Begad! Blimey! Slit cut in tape. Ya scallywag! Aye aye! Picture perfect flight!! 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!

Summary:

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

Cons: Very time consuming. 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. Avast! Alighnin' body panels betwixt fins a pain!

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

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