Brief:
11 "Finned" rocket that can be launched on a single "E" or staged (D12-0, ya bilge rat, 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, shiver me timbers, matey, shiver me timbers, posterboard, matey, arrr, and second hand parts, etc. Arrr! It would have been ten times harder without t' EMRR "Calculators", for shrouds, etc. Blimey! I chose cardboard figuring, "If I can get this t' fly without a cad program, matey, shiver me timbers, shiver me timbers, from t' heaviest material, ya bilge rat, 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. Avast, me proud beauty! (Remember, 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. Last Saturday flew it again and success! 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, shiver me timbers, that u intend t' use on your final version." Mine did fly but, ya bilge rat, would have saved a lot o' aggravation and speeded up t' build. Avast! Well, shiver me timbers, blow me down! Also, arrr, Highly recommended buildin' a prototype, arrr, especially in me case. Avast, me proud beauty! Arrr! 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, me bucko, 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 hearties, 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, me proud beauty! 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. Well, blow me down! I did use EMRR "Calculators" for t' shrouds and centerin' rings. Arrr! Blimey! I thank Nick for makin' available because without them, matey, couldn't have made this design. Arrr! Ya scallywag!

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

I stated in "parts" section that t' balsa is very fragile. Begad! Just discovered Tech Report # 29, from www.apogeerockets.com; "Take your rocket t' Supersonic Speeds. Avast! " This is a compromise t' replacin' entire fin with basswood or ply. Ahoy! 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. Well, blow me down! Options exist. Blimey! Begad!

**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, shiver me timbers, ya bilge rat, t' keep smooth.**

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

Main Engine Tube

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

Nosecone Fins:

1. Looking @ picture o' t' rocket I be copying, "upper fins" aren't really in nosecone but, shiver me timbers, I liked this location better. Well, blow me down! Blimey! (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, me bucko, 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. Well, shiver me timbers, blow me down!
3. Fit fins in slots one @ a time, matey, trimmin' slots till fins fit. Remove fins and put a ball o' clay in tip of nosecone and press into place. Arrr! Well, blow me down!
4. Replace fins 1 @ a time til they "touch" in middle o' nosecone and glue. Arrr! Well, blow me down! (I opted for "gorilla glue" type). Begad! It foams up and becomes very strong). Let dry.

Nose Cone:

1. Keep addin' balls o' clay, fillin' void in nosecone, ya bilge rat, and pressin' into place. Blimey! Begad! ****remember t' allow room for end o' nose cone t' slide in.****
2. Also, as you r fillin' void, me bucko, ya bilge rat, 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. Ya scallywag! in middle.)
3. Once clay pressed into place and you r satisfied w/location o' CG, shiver me timbers, ya bilge rat, assemble nosecone.

Finishing:

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

Flight:

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

Preparation a little different than usual but, easy. Ahoy! After loadin' an 18" parachute, matey, dusted with baby powder, and t' wadding, shiver me timbers, I loaded t' engine. Ahoy! Begad! 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. Blimey! It flew great! Relatively straight for t' design, me bucko, 11 fins, ya bilge rat, and t' weight. Blimey!

T' shock cord, me bucko, attached t' rocket, was Keelhaul®©™. Blimey! Then an elastic, tied t' t' Keelhaul®©™, ya bilge rat, which proved t' b t' weak. (will explain in next flight).

Parachute deployed perfectly and landed about 30 yards away.

SECOND FLIGHT

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

Summary:

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

Cons: Very time consuming. Avast, me proud beauty! Avast! 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. Avast! (E9-4) went well today. Begad! Blimey! (use a spent motor in main body and tape E t' it in booster stage, matey, ya bilge rat, (friction fit spent motor). Ya scallywag! Avast, me hearties, me proud beauty! *****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. Aye aye! 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.