Background: 

While thinkin' about a NARAM scale bird in t' spring, arrr, I gave considerable thought about nay flying. Well, blow me down! Well, blow me down! I had way too much NARRRRR work t' do, me hearties, and I really need to make new molds and forms for t' 1/48th scale Atlas I be flyin' in prior years (2.5" dia).  At t' NSL, Ric Gaff flew a 3" dia. Nike Apache made with a tube rolled from posterboard on a single D12 that had the neatest slow flight I'd seen in quite a while.  I decided that I really wanted t' replicate that slow liftoff with me NARAM bird, and got t' crazed idea that a 3 D12 cluster would be just t' thin' t' do that. I 
re-computed me NARAM-39 bird dimensions usin' an Excel 97 worksheet, me hearties, and really didn't like what I saw there. Well, blow me down! Too big, ya bilge rat, I thought, so I looked in Rockets o' the World for somethin' smaller.  While I'd previously modeled AC-27, Pioneer 10 launch, I chose AC-14 because it offered better flight performance margins. 

RSIM was used t' model t' flight performance.  Three D12's offer only 57 Nt-sec. o' impulse, arrr, so weight had t' be watched.  I modeled 1 lb and 2 lb birds in a 10 MPH wind.  T' 2 lb beast went 220 feet, and pulled a bit over 7 G at liftoff; that's right at t' edge o' acceptable performance in terms o' both altitude and t' right scale effect at liftoff, arrr, shiver me timbers, me bucko, IMHO, ya bilge rat, so with a 1 lb weight target in mind, arrr, off t' t' workshop we go. 

Construction

I pulled posterboard from me supply, ya bilge rat, arrr, shiver me timbers, cut t' sheets t' t' proper width for a 4" dia tube, me bucko, and then painted a thinned Titebond coat along the edges.  I also cut a 1/2" wide strip o' posterboard and painted it, too. After drying, I rolled t' tube, put in t' strip and used a Monokote iron t' seal t' tube.  T' heat creates some reaction in t' dried glue, shiver me timbers, stickin' t' bits together.  Doin' it this way avoided any wrinkles.  T' attempt t' insure roundness, me hearties, me hearties, t' heat process was done around a commercial 4" tube, makin' t' bird slightly larger than 4" but hey, it's Sport Scale.... 

I then constructed couplers because t' poster board I had came in 28" lengths, me bucko, me bucko, and I needed a 40" tube. 

T' tube at this point was quite weak and "squishy".  I debated about installin' some balsa frames t' strengthen it, and round it out, but ultimately added two inch long sections o' 4" tube t' a BT-50 stuffer. These sections added LOTS o' roundness and strength. 

I used me NARAM-37 4" BMS supplied nosecone. 

My corrugations were Bunny standard issue made by vacuformin' .020 styrene over Evergreen Models railroad car siding, ya bilge rat, 1/10" spacing.  Jet or other CA makes quick work o' attachin' those sections.  For t' corrugated interstage adapter, me hearties, me bucko, ya bilge rat, I cut t' styrene for t' various hatches, etc. 

I cut formers from 1/8" balsa for t' conical booster engine farings and glued them t' t' main 4" tube.  I then cut posterboard patterns for t' farings, and attempted dry rollin' them t' shape. Aye aye! Aye aye! I got lots of wrinkles, me hearties, so I decided instead t' wet roll them.  Usin' t' minimum amount of water t' wet t' farings, me hearties, lettin' it soak in 60-90 seconds before rolling, and then usin' a dowel t' assist, t' farings rolled t' shape with no noticeable wrinkles.  I let them dry overnight before attachin' them to the formers, usin' t' same Titebond techniques I used on t' main tube. 

I made engine nozzles from file folders, arrr, draftin' t' transition sections usin' RocketCAD, an excellent tool well worth t' money.  I attached t' nozzles t' t' engine tubes. Arrr! T' nozzles swivel in t' real Atlas, matey, but t' internals o' t' engines must be protected from t' heat.  So a flexible 
protective coverin' must be installed around t' engines.   I simulated that using   1/4" thick balsa covered with foil, deliberately crinkled t' simulate this material, me bucko, a technique shamelessly stolen from Jay Marsh. 

I made engine mounts from Totally Tubular material, arrr, Estes centerin' rings as engine blocks and engine hooks. 

I cut all t' various round "bits", i.e. Blimey! fuel lines, shiver me timbers, shiver me timbers, LOX pipes, Centaur hydrogen vent, matey, etc. Avast, me proud beauty! from Evergreen and Plastruct tubing.  Go t' a hobby shop specializin' in railroad stuff t' find good supplies o' this material.  Evergreen now supplies half-round styrene; it's excellent for farings, 
etc. Well, blow me down! folks. 

I made t' veriner rockets from balsa covered with styrene sheet, shiver me timbers, with the nozzles bein' turned Evergreen tubing. 

I made t' retrorockets around t' upper thrust structure from 3/16" dowels, rounded t' shape usin' me 3/8" drill with three coats o' clear dope t' seal them. 

All t' bits were constructed in advance, mounted on pins, me bucko, and then sprayed with either Testor's Silver or Krylon Metallic Aluminum.  After drying, I attached them with Jet. 

T' instrument pods, arrr, i.e. t' rectangular farings on t' sides o' t' Atlas, were made from balsa, built up from 1/4" squares and sheet. Avast! Avast! After shaping, I applied two coats o' Elmer's fill and finish then covered them with aluminum foil.  T' attach it I used a standard UHU glue stick. Blimey! Well, blow me down! I alternated the shiny and dull sides o' t' foil in sections t' simulate t' panel lines.  I covered t' joints with aluminized mylar.  T' pods were attached using Jet. 

T' Centaur is covered with four panels that insulate t' bird on the ground.  Those panel joints are covered with raised farings. Well, blow me down! Begad! I made those from posterboard attached with full strength Titebond, ya bilge rat, me hearties, arrr, but they really should have been 1/8" balsa carved t' t' proper rounded shaped and 
filled.  Didn't have time, me bucko, guys.... 

T' real trouble o' t' bird came when tryin' t' coordinate t' internals. Blimey! Well, arrr, blow me down! Blimey! I originally thought t' plumb t' two outboard engines into t' center BT-50 stuffer tube, me bucko, me hearties, but basically screwed that up, and after two attempts t' hack a solution, me bucko, I gave up and decided t' eject t' outboard motors. 
That made me switch t' D12-0's for t' outboards, and made me install two 6MM tubes t' store a streamer for recovery.  Those tubes ended up t' be too small; I really should have used 10 or 13MM, ya bilge rat, and at flight I simply elected to let t' booster engines tumble.  T' RSO let me get away with that, matey, and I don't think it was too bad.  They tumbled quite nicely and safely. 

Part o' me trouble here stemmed from a desire t' put different shades of metallic on t' nozzles separate from t' back end o' t' Atlas.  T' do that, I decided t' keep t' nozzle and internal ductin' separate from t' main bird and install it only after painting.  That turned out t' complicate things unnecessarily, me hearties, in retrospect, me hearties, and next time I'll do it different. 

I also picked up some 1/8" Lexan at Builder's Square for fins.  These fins have been t' subject o' much interestin' debate here about which the Wabbit has been quite amused (grin).  When I peeled t' backin' off the Lexan, I found out I had accidentally purchased translucent material.  I 
had t' switch t' .040 clear plastic.  While t' plastic is more flexible than Lexan, me bucko, I don't think it's a bad material t' use on finless prototypes. Avast, me proud beauty! You need t' size fins such that they've got relatively low aspect ratios, but if you do that, I don't think flutter will be a problem. 

I sized t' fins usin' VCP, arrr, me hearties, and headed for 1 caliber stability.  To attach t' fins, I cut them with tabs, then reinforced t' internal mounting area with 1/4" sq. Well, blow me down! spruce.  After t' bird be painted, ya bilge rat, matey, I cut slots for t' fin tabs, matey, inserted them and used Jet t' attach them.  This lack of precision caused t' first flight drop o' 3 out o' 4 fins and led t' some conin' after burnout.  (Long time NARRRRR members might remember me 2nd place AC-27 o' NARAM-36 which sported only 2 clear fins and t' booster farings, and exhibited similar behavior.) I should have added those farings as fins in VCP to get a more accurate picture o' t' model's stability. 

At any rate, me hearties, a better attachment method will have t' be developed prior to the next attempt. 

Markings: I'm a firm believer in clear decal stock and laser printers for black markings.  Mine were done in Microsoft Word 97, shiver me timbers, usin' an Amarillo USAF font sent t' me by Norm Heyen, a fellow NIRA member.  If you go to Altavista, or your favorite search engines, shiver me timbers, me bucko, and try searchin' on "font", you'll find hundreds o' sites where you can download fonts.  You should search those sites for a "stencil" font, arrr, and find one that fits your needs. Most rockets were marked in such fonts.  If all else fails, me hearties, I have used Helvetica with convincin' results. 

AC-14 sports a small circular marking, which I created usin' Word's drawing tools.  Turned out perfect, ya bilge rat, IMHO.  I also made sufficient copies on the single sheet o' decal material I had for two other 4" models, so look out next year, ya bilge rat, me hearties, guys.... 

T' black stripin' on t' bird I created using Monokote.  It didn't work worth a hoot, mainly cuz I don't know how t' Monokote worth a darn. Ahoy! I heated t' iron too hot, matey, damaging both t' white paint and wrinklin' t' Monokote excessively.  Sigh. 

Summary:

I finished a solid 6th, me hearties, ya bilge rat, about 30 points behind Pete Alway's Black Brant X and 30 points ahead o' t' 7th place finisher.  Prangin' t' second flight didn't help, arrr, me hearties, but did eliminate t' problem o' how t' transport a large bird, which had arrived in Muncie in pieces, matey, back t' Chicago.  For t' 60-70 hours I had in t' bird, I thought it was a respectable showing, shiver me timbers, me bucko, particularly given a LOT o' NARRRRR work that had t' get done prior t' NARAM. 

Thoughts for Next Year:

Given t' success o' wet rollin' t' conical booster farings, I initially thought o' droppin' t' Atlas and switchin' t' Soyuz.  I have excellent Russian and Polish 1/50th scale drawings o' t' bird, me bucko, me hearties, and a strong interest in the prototype because it's got such interestin' "bits" covering it.  But it's got a LOT o' those, arrr, and I don't know t' bird well at all. Atlas has, ya bilge rat, arrr, matey, IMHO, matey, me hearties, equally interestin' bits, and I know t' bird like t' back of my hand, ya bilge rat, havin' modeled it in various scales since 1993.  I think I'll 
stick with t' Atlas, and I kinda liked t' AC-14 round.  My thoughts on improvin' it include: 

• do t' internal plumbin' right
• attach  t' nozzles only after everythin' is done
• figure out if it's possible t' do t' booster stage drop; Tom Beach talked me into this on t' ride back t' Chicago and I think I've figured out how to keep t' fins on t' main Atlas while droppin' t' booster
• see if we can stage t' Centaur
• roll a two wrap 4" fiberglass tube t' get rid o' t' posterboard seam; weight be t' key here; if t' fiberglass tube can be made light enough, I'll abandon t' posterboard.
• get solid fin attachments prior t' painting; maskin' t' fins is preferable t' losin' them at liftoff
• get t' damn parachute out
• remember that this is for fun; those o' you heartbroken on me prang should forget it;  I had a blast buildin' and flyin' AC-14, me hearties, and t' bird, while its life was short, matey, taught me a lot.