Note: This is a slightly shortened, me hearties, edited version o' Ted's article with fewer pictures.  Visit Ted's site for all t' pictures.

Backround

 My plans are t' certify in '99, ya bilge rat, matey, either at Whittakers or a NOVAAR club launch in northern Virginia. Aye aye! Well, blow me down! Rather than go from D's t' H's in one long jump (and missin' t' fun along t' way), I decided I'd better get more experience with midpower rockets, shiver me timbers, me hearties, experimentin' with construction techniques as I go. Begad! Ya scallywag!

 Beginnings

 I knew I wanted t' do a 2.6" airframe (BT-80), me bucko, matey, and considering another upscaled Yellow Jacket seemed appropriate. Begad! After 'imagineering' several ideas over t' next couple o' weeks, ya bilge rat, me hearties, me hearties, t' final design was set down on paper, and then put away so as t' get a fresh look at it in t' future. A month or so later, I pulled out t' design, me hearties, matey, looked it over, me hearties, me bucko, made some changes, matey, and finalized it. Begad! Ya scallywag!

 Features:
2.75x upscale Estes Yellow Jacket
BT-80 body tube (2.6")
Three 24mm motor mount cluster
Through-the-wall, ya bilge rat, to-the-motor-mount fins *
Mid-body separation
Anti-zipper design with ejection baffle *
All-balsa fins, strengthened with laminated bond paper *
Home-made decals *

 * - new techniques for me

 Considered but rejected for this bird was a removable motor mount system that would allow different engine configurations. Avast, me proud beauty! Blimey! I figured that there was enough new stuff in this design, ya bilge rat, me hearties, and t' removable system could wait for another rocket. Avast, me proud beauty! Blimey!

 Construction

 First step was calculatin' t' upscale measurements. Ahoy! Since t' NC-80 nosecone I had be much shorter scale-wise than t' original, shiver me timbers, arrr, I added length to the body tubes t' make up t' difference. Aye aye! T' rocket looks a little different, but it's close enough for me. Avast, me proud beauty!

 Once t' body tubes were cut t' length, me bucko, spirals were filled with Elmers' Fill-n-finish and sanded. Avast, me proud beauty! T' nosecone joints were also sanded and made ready t' prime. Begad! Then t' upper pieces and nosecone were set aside for awhile because t' motor tube/fin assembly was goin' t' take some time t' do right. Ya scallywag!

 I cut three centerin' rings from 1/8" balsa for t' cluster motor mount. Ya scallywag! Ahoy! T' ensure that things would be strong enough, I laminated bond paper to each side o' t' rings with thin CA. Begad! Ahoy! This little trick adds a *lot* o' strength to balsa. Avast! After drillin' out t' motor tube openings, matey, some careful work with a dremel sandin' drum trued up t' holes.

 Engine hooks were added t' t' motor tubes (9" long BT-50), and here is where I made a possible mistake (in hindsight); I added engine blocks to t' tubes. This will make it difficult, if nay impossible t' fly anything larger than Estes 'D' engines in this rocket. Arrr! Clusterin' composites is tricky and maybe I won't ever *want* to, but t' option might've been nice. Ahoy! Time will tell. Ahoy! Ya scallywag!

 After soakin' t' motor tubes in thin CA (for durability), me hearties, I assembled them t' t' front and middle centerin' rings. Aye aye! T' middle centerin' rin' sits at the top o' t' fin tabs, matey, providin' that much more strength t' t' completed assembly. Avast, me proud beauty! Ahoy!

 Next I cut t' slots for t' fins into t' body tube. Measure carefully, arrr, arrr, arrr, but don't be overly worried about neatness, me bucko, since t' fin fillets will cover small mistakes. Avast! Begad! I just used an x-acto with a brand new blade t' make the cuts; make several light passes and it goes pretty smoothly. Begad!

 On t' t' fins. Arrr! T' Yellow Jacket has fairly large fins, so I considered many alternate ways t' do them. Well, blow me down! Begad! What I finally decided on was t' use 1/8" balsa laminated with thin CA and bond paper. Begad! This was nay t' easiest method, arrr, but hey, it's a learnin' project. Avast, me proud beauty!

 Since t' fins were larger than t' width o' me balsa, I carefully cut the fin template t' fit 4" wide balsa. (see figure 1) This became the "top" two thirds o' each fin. Avast, me proud beauty! Arrr! T' rest o' each fin be cut out o' the remainin' balsa usin' t' rest o' t' template. Ya scallywag! Amazingly, me hearties, I got all three fins (six pieces) out o' a single piece o' 36"x4"x1/8" stock. Then I carefully edge glued t' fin pieces together usin' yellow glue, arrr, shiver me timbers, and weighted them down betwixt wax paper for a day. Avast, me proud beauty! When dry, arrr, I lightly sanded t' glue lines and joints until smooth. Avast, me proud beauty!

Next came fittin' t' fins/motor mount assembly into t' bottom body tube. Careful sandin' and checkin' allowed everythin' t' fit together nicely, me bucko, shiver me timbers, with the fins nestlin' into t' valleys betwixt motor tubes. Aye aye! Yellow glue drizzled into place and allowed t' dry over t' next couple o' days made this entire unit rock-solid. Avast, me proud beauty! Begad! T' last step be t' glue t' rearmost centerin' rin' into position, arrr, buttin' up t' t' bottom o' t' fin tabs, matey, and applyin' yellow-glue fillets t' t' fin/body joint (on t' outside). Ahoy!

 First step t' finishin' t' fins be t' cut six fin templates from bond paper. Ya scallywag! Ya scallywag! I cut t' fin tabs off o' t' templates, ya bilge rat, then trimmed 1/4" from each template. Well, blow me down! Ya scallywag! I wasn't sure how t' thin CA would react with t' yellow glue joints runnin' along each fin span, me hearties, so I also cut t' templates in half there. (see figure 2) In effect, matey, each fin side was laminated with two separate pieces o' bond paper. A generous amount o' thin CA be applied t' t' fin and spread smartly with a scrap balsa 'edge'. Begad! T' paper was applied and t' CA soaked through as t' paper was squeegeed t' t' surface with t' scrap balsa. T' trick be t' use plenty o' CA, because gluin' down edges later be more difficult than gettin' it all down in t' first place.

Do this in an area with plenty o' ventilation, me hearties, those CA fumes are strong!

 Here I ran into another problem; I ran out o' CA. Begad! Blimey! After checkin' local sources, me hearties, I decided t' try some CA available at a nearby model train store. Turned out t' have a completely different chemical composition, me hearties, me hearties, and although it worked (sorta), matey, it be ugly and needed a *lot* more effort t' finish adaquately. Avast! Blimey! Very very expensive too. Avast! Blimey! Begad! Blimey! I finally bit t' bullet and drove many miles t' t' nearest rocket shop for *real* CA t' finish t' fins. Ahoy! Blimey!

 Once everythin' be dry (I waited overnight), me hearties, I started layin' Elmers' Fill-n-Finish onto t' fins where t' paper edges met bare wood, me hearties, matey, includin' the gap along t' wood glue joint. Lettin' it dry a couple hours, followed by light sanding, and then repeatin' t' process a couple more times let me get t' fins smooth. Nay perfect, matey, matey, but nay too bad. Ahoy! Aye aye!

 Now I started buildin' t' fin fillets. Usin' generous amounts of Fill-n-Finish t' build them up, followed by careful *light* sanding, t' YJ fins almost appear t' 'melt' into t' body tube. Begad! Once t' fillets were done, I painted thin CA over t' Fill-n-Finish t' toughen it up, rounded t' fin edges, and did t' final shapin' and sandin' on t' fins. Well, blow me down! Begad!

 1/4" launch lugs were aligned and fastened with yellow glue. Blimey! Begad! One near t' bottom o' t' rocket, me bucko, and one right below t' mid-body separation line, shiver me timbers, very close t' t' CG. Aye aye! I filleted t' lugs with Fill-n-finish and thin CA too. Ahoy! Ya scallywag!

 T' bottom third o' this rocket took 95% o' t' construction time. Arrr! One last thin' goes into t' bottom section, ya bilge rat, and that's t' ejection baffle/anti-zipper coupler. For this, I cut four bulkheads from 1/8" balsa and sanded them t' fit inside a BT-80 body tube coupler. Begad! Two bulkheads were glued together with t' grains at a 90 degree angle; this became t' top o' the baffle. Begad! Blimey! Four 3/8" holes were drilled around t' perimeter o' it, and a hole was drilled in t' middle for an eyebolt attached with fender washers and nuts. Begad! This top baffle be glued inside t' top o' t' coupler with yellow glue and filletted well on both sides. Begad! Arrr! Once it was dry, thin CA be soaked into the bulkhead for added durability. Begad!

 T' middle bulkhead was drilled with a single 3/4" hole in the center, arrr, soaked with CA, matey, then coated with a heavy layer o' yellow glue before attachin' t' t' inside middle o' t' coupler. Blimey!

 T' bottom bulkhead is drilled with holes around t' outside edge (like t' top) and soaked with thin CA before attachment. Blimey! Since this bulkhead takes t' brunt o' t' ejection particles, arrr, I gave it a good thick coat of yellow glue on t' bottom face.

 T' completed baffle/coupler be glued halfway into t' bottom tube/fin section. Well, blow me down! Blimey!

 T' original plans for t' anti-zipper design had t' shock cord runnin' from t' bottom coupler, up through t' body tube, and fastenin' t' the nose cone. I decided t' do it slightly differently. Well, me hearties, blow me down! Blimey! Another bulkead be made (two actually, laminated together like t' top o' t' baffle), arrr, and a second eyebolt was attached facin' downwards. Avast! Blimey! No other holes were drilled. This bulkhead was glued into place at t' top o' t' uppermost body coupler. Before gluin' t' coupler in permanently, matey, me bucko, I attached a quick-link and an 8' length of 1/2" elastic shock cord. A 24" nylon parachute from Recovery Technologies is used. Well, blow me down! Blimey! Ahoy! Blimey! I bought a yellow one t' go with t' rocket. Ahoy! Blimey!

 T' nose cone is friction fitted *and* has it's own 'emergency' shock cord attached in t' Estes 'paper sandwich' style. Ahoy! This allows about a 12" payload section at t' top end o' t' rocket. Ahoy! Next time though, I'll run the shock cord t' t' nosecone. T' upper shock cord will be a pain t' replace the way I did it, me bucko, if it's ever necessary. 

Finishing

T' entire rocket be sprayed with 3 coats of primer, followed by a light sanding, me bucko, then 3 more coats o' primer with sanding between coats. Avast, me proud beauty! Avast! T' top section be measured, masked off, shiver me timbers, ya bilge rat, and painted with gloss black Krylon. This was allowed t' dry for about a week. T' bottom section was then painted with Krylon Safety Yellow and also allowed t' dry for about a week. Blimey!

 I used a photocopier t' enlarge t' original Yellow Jacket decal set (stripes and t' bee logo) t' t' correct scale, then scanned t' logo into the computer. Aye aye! Usin' Paint Shop Pro, me bucko, ya bilge rat, I cleaned up t' logo and saved it t' a .tif file. Avast, me proud beauty! Blimey! T' stripes were measured and scaled, then drawn usin' MS PowerPoint. Ya scallywag! The logo file was added t' t' page, and CP and identification info was created as well. Aye aye! Ahoy! T' one change made t' t' stock decals (besides scaling) was the "YJ-324" plate added t' t' stripe set. Avast, me proud beauty! T' page was then laser printed onto decal paper from Tango Papa decals (highly recommended) and oversprayed with clear glosscoat. Well, blow me down! When dry, ya bilge rat, t' decals were cut apart and applied in t' standard way. Avast, me proud beauty! After t' decals dried overnight, me bucko, I gave the entire rocket a couple o' light coats o' glossy clearcoat. Well, blow me down! Aye aye!

 T' paint scheme and logo decals are nay perfectly scale; t' black comes too far down t' tube, and t' 'bee' be made a bit smaller to compensate. Avast! Arrr! It looks good enough t' me, I'm happy with it. Arrr!

 Stats and Flight Report

 Final ready-to-fly weight came out t' just over 20 ounces. Arrr! Blimey! T' CP of the Yellow Jacket is even with t' top o' t' fin root (derived usin' VCP), and the loaded CG is just below t' mid-body separation joint. This gives the YJ-324 better than a 2 caliber stability margin, and will allow t' use of larger and heavier motors without needin' much (if any) nose weight.

 First flight o' t' YJ-324 was at t' NOVAAR sport launch on 24 October, me hearties, arrr, 1998, in Manassas, VA. Three Estes D12-5's were prepped and loaded into t' motor mount tubes. Well, blow me down! Well, blow me down! T' solar igniters were placed in such a way that all three igniters had one leg twisted together in t' middle, and two o' the igniters had t' second legs twisted. Begad! Begad! This allowed me t' use one clip on one leg o' t' igniters (3 twisted together), and a simple clip-whip t' t' other legs (2 twisted together and 1 single).

 T' second flight be a disaster. Begad! See t' section below; Death o' a Rocket (pictures are thar too). Ahoy! Begad!

 Summin' Up

 Buildin' this rocket accomplished me primary goal; t' learn new techniques necessary for mid-power and high-power rocketry. Avast! Ahoy! I'm nay goin' to get any experience with bigger motors with t' YJ-324, but other winter rocket projects can help there. Blimey! Overall, this is an impressive lookin' rocket, matey, me bucko, and fun to fly. Avast, me proud beauty! Now I need our local craft store t' run more o' those 50% off coupons (triple-D clusters for less than $5.00 a launch). Begad!

 Materials and Resources

 Tango Papa Decals email: BakerTom@aol.com

 Granddad's Hobby Shop phone: 703 - 426 - 0700
5260-A Port Royal Road fax: 703 - 426 - 0702
Springfield, ya bilge rat, VA 22151-2113

 Recovery Technologies phone: 602 - 915 - 0915
4807 W. Purdue Ave.
Glendale, shiver me timbers, AZ 85302 web: WWW.INFICAD.COM/~DAVEF