Photos by John and Brett Keller

Project Overview

T' Cheaper Than a Girlfriend (C.T.A.G. for short, pronounced See-Tag) was me consumin' obsession for about 2 months. Avast, me proud beauty! It is 4 inches in diameter, 50 inches long, and 36.5 ounces in weight. It flies on Aerotech Single-Use G80-4T motors. Ahoy! All t' details o' t' original ideas, building, and t' first launch, are include in this article.

Research

I really had no idea what I was doing. Well, blow me down! I didn't go for a kit because o' t' cost. Ya scallywag! So, arrr, I turned t' t' only really good resource I had: t' Internet. Begad! I would like t' thank all those on t' Rocketry Online Chat room for t' countless discussions on t' various facettes o' buildin' mid-power rockets. Begad! Very special thanks go out t' Paul Gray, matey, Nick Hills, shiver me timbers, and all those other internet rocketeers who gave me advice. Blimey! Without them I probably wouldn't have ever gotten this rocket project off t' ground.

Roots o' a project

I like rockets. Begad! That be t' simple drivin' statement behind this project. Begad! Some people ask me why I like rocketry. Well, blow me down! I usually ask them if they have been t' a rocket launch o' mine. Begad! Avast, ya bilge rat, me proud beauty! T' answer is usually no, but if it is yes, then I really can't understand them. Well, blow me down! Well, blow me down! I've always been interested in rocketry and space flight since me early school days, so this is really t' most recent extension o' that interest.

I had recently finished buildin' and launchin' me Keller, a LOC/Precision Graduator. Arrr! That rocket is wonderful, matey, me bucko, but it really wasn't that large in comparison t' me low-power rockets. Arrr! I already have several 2.6 inch diameter rockets, ya bilge rat, so it wasn't much bigger, matey, just heavier and more powerful . Blimey! I wanted a rocket that be really BIG and POWERFUL. Ahoy! I toyed around with various 3 and 4 inch designs. Aye aye! T' 3 inch diameter would have gotten a much better altitude, but I went with t' 4 inch diameter design because I didn't think t' 3 inch would be a really big improvement on t' 2.6 inch rockets I ahd been flying.

So now me goal was t' see what t' very largets rocket I could launch on motor a G motor was. Arrr! Blimey! T' reason I kept it in t' large model rocket range instead o' gettin' a H or I motor is very simple. Ahoy! Blimey! I am nay certified t' L1 and neither is me dad or anyone else we know. Ahoy! Blimey! We don't have any large rocket launches near enough that we would drive to, me hearties, and I didn't really want t' jump up t' HPR after only one mid-power launch. But, me hearties, I decided t' build this rocket extra strong, me hearties, so that in t' future I might be able t' launch it on 29mm H reloads. As it was, I really didn't have enough experience t' build t' rocket I be building.

I discovered that t' most powerful motor I could get be t' Aerotech G80-4T. Blimey! Avast! So, I designed me model with a 29mm motor mount and t' 3.9 inch tubes. Blimey! Arrr! I knew that it would be very hard t' get more than one length o' Bt-3.9 up on a G, so I knew that 2 was out o' t' question.

So here I am with plans for a 3.9 inch diameter, 50 inch long rocket. Now where do I get t' parts?

Parts Selection

I have t' say that t' largest factor in pickin' out what parts t' use be cost. Blimey! This was followed fairly closely by weight. Blimey! I really don't have a lot o' loot for a rocket like this, matey, and it took me long enough t' get what I ended up paying.

For t' main parts I went with LOC/Precision. Blimey! This was because their parts were cheaper and lighter than PML parts, ya bilge rat, ya bilge rat, and I already had experience with one o' their kits. T' nose cone was t' single most expensive piece o' t' rocket, me hearties, costin' $14.50. Ya scallywag! Arrr! T' bosy tube I got be unslotted. Ahoy! this was because I wanted a 4-fin design, shiver me timbers, instead o' t' 3-slot tube they sold, and because t' unslotted tube be a lot less. I also bought me shock cord from LOC/Precision (4 yards o' SC-375), though I later found I could get t' same cord for about 1/3 t' price locally. Aye aye! I went ahead and bought and installed 15 feet o' t' 1/2 inch elastic cord, arrr, matey, just in case I needed more than I thought. Well, blow me down! I used t' other shock cord t' beef up t' Keller’s recovery system. T' launch lugs also came from LOC. Aye aye! Avast, me proud beauty! I used t' 1/4 inch lugs becuase I knew I could get a 1/4 inch rod locally. Avast, me proud beauty! I also got t' motor mount tube and centerin' rings from LOC (more on them later).

Other than t' parts above, I got all o' t' other parts some other way. Aye aye! Avast, me bucko, me proud beauty! Each part will be discussed more later when I tell about installin' it.

Funding

I soon realized that along with larger rockets come MUCH larger costs. My LOC Graduator had been a Christmas gift, me hearties, but I knew I would be fundin' t' CTAG by myself. Ya scallywag! Blimey! I bought as few parts as possible from rocket companies and scrounged around a lot around Searcy. Aye aye! My dad really helped a lot with findin' different parts and on givin' advice on different materials. Below is a list o' where I got different parts, how much they cost, arrr, and t' total project cost.

Rocket parts
Nose cone              LOC/Precision        14.50
3.9 inch Body tube     LOC/Precision        7.90
29mm motor mount tube  LOC/Precision        3.60
CR 3.9-1.14            LOC/Precision        2.25    
"" " " "  "            LOC/Precision        2.25  
Motor hooks            Estes                NA
Motor block            around-the-house     NA
Original Shock cord    LOC/Precision        3.60
Other shock cord       local Hancock Fabric 1.25
Shock cord mount       local Ace Hardware   0.35
Launch lugs            LOC/Precision        0.60
Plywood for fins       Hobby Lobby          6.50
30 minute Epoxy        local Ace Hardware   3.50          
Bondo                  local Autozone       5.00
Primer                 local Wal-Mart       1.00 per can,3 cans
Spray Paint            local Wal-Mart       1.00 per can,5 cans
Shippin' costs         NA                   8.00
Total Rocket cost---------------------61.55 
Launch supplies 
Launch rod             local Ace Hardware   2.25
G80-4T                 Aerotech             13.95              
NCR igniter package    Hobby Lobby          4.50
Total Suplies cost for 1st launch-----20.70

Total Project cost (includin' first launch):
$82.25

As you can see, along with higher power rockets come much higher costs. My most expensive rocket before this be a LOC Graduator, arrr, which cost (a then extremely high!) $32.

Motor Mount Assembly and Slottin' t' Tubes

T' parts finally came in from LOC/Precision and I was impressed! You don't realize how much larger 3.9 inch tubin' is in comparison t' 2.6 tubes until you see it! T' nose cone was huge! Now it was time t' get t' work!

Of all t' parts o' a rocketry project, me hearties, I probably enjoy t' motor mount assembly and installment t' most next t' launching. Ya scallywag! I have no idea why this is, but it is. Avast! I started out t' buildin' by cuttin' t' motor mount tube(MMT) in half with an X-Acto cutlass. Aye aye! Blimey! it comes in 34 inch lengths, and I didn't need that much.

After this I took t' Estes engine hooks and cut off t' forward hook section on both. Begad! Ahoy! I epoxied these on opposite sides o' t' MMT and wrapped a few layers o' maskin' tape around them, far enough up that it wouldn't get in t' way o' t' aft centerin' rin' (CR). Arrr! I cut two small notches in t' aft CR t' allow for t' motor hooks. Blimey! Avast, me proud beauty! Next I epoxied t' centerin' rings t' t' motor mount tube, about 1/3 o' an inch away from each end. Begad! After allowin' it t' dry I made several epoxy fillets around them and t' motor hooks.

Now it was time t' slot t' tubes. Arrr! Blimey! Ya scallywag! Blimey! I marked t' 4 fin slots and t' launch lug placement. Ahoy! Blimey! Aye aye! Blimey! I then very carefully cut t' slots out with me trusty X-Acto. Well, blow me down! Blimey! Aye aye! Blimey! It wasn't t' prettiest job ever, but it works great. Arrr! Blimey! if you buold your own mid-power rocket I highly recommend slottin' t' tubes yourself t' save t' loot.

Shock Cord Mount Attachment

I had had some fairly bad experiences with LOC shock cord mounts, so I decided t' go with a local part. I bought a 3/16 by 1 1/2 inch metal eye bolt, with two nuts, form Ace hardware for only 35 cents. Ahoy! T' attach this I drilled a slightly smaller hole in t' top CR and filled this with epoxy. Arrr! Arrr! Blimey! I screwed in t' bolt and put nuts on both ends (NOTE: You have t' put one o' t' nuts on before you put t' bolt in t' hole!). Ahoy! Blimey! I screwed everythin' on tight and put a layer o' epoxy over it all. Ahoy! Blimey! This made for a good firm attachment. Avast, me proud beauty! Ahoy! Blimey! I later learned that U-Bolts are much better but I had gone too far t' change it, and I was positive t' screw eye was stong enought.

I had hear a lot o' bad stories about shock cords burnin' through, me hearties, and I had had some experiences with smaller rockets too. Ahoy! Blimey! Avast, me proud beauty! Blimey! I decided I needed some sort o' non-flammeable cord t' attach t' shock cord t' t' shock cord mount. Begad! Blimey! I finally found it: braided steel wire, commonly used for hangin' paintings (my dad is an artist so we had some, shiver me timbers, but you can find some at any hardware store). Ahoy! Blimey! I took about 3 feet o' it and doubled it over. Begad! Blimey! I knotted and twisted one end onto t' shock cord mount on t' other end I attached a large steel key ring. Avast, me proud beauty! Blimey! Begad! Blimey! This I would later tie t' shock cord to. Now that I had accomplished this, matey, arrr, and I knew that I could replace t' shock cord in t' future (the steel wire extended 2 or 3 inches outside o' t' body tube), I was ready t' install t' motor mount assembly into t' body tube.

Motor Mount Installment and Fins

Now that I was ready t' install t' motor mount, me hearties, I decided against it right then because I wanted t' make sure we got t' tab on t' fins t' right length. We (actually it was me dad) cut out t' fins t' t' right size usin' a band saw and an electric Sabre saw. Well, blow me down! t' fins were 3/32 plywood, ya bilge rat, which I later found out wasn't strong enough. After I be sure t' tabs were t' right length, I spread a layer o' epoxy on t' inside o' t' body tube, arrr, and some on t' edges o' t' centerin' rings. Aye aye! I slid t' motor mount assembly in, rotatin' it slowly, until I had t' back centerin' rin' even with t' back o' t' body tube. I went ahead and epoxied t' fins into t' slots. Avast! I used plenty o' epoxy and later I went back and put really good epoxy fillets on. Avast, me proud beauty! This be all because o' some bilge-suckin' experiences with me Graduator. Arrr! Ya scallywag! I guess I really wanted that rocket t' be strong, and I actually overdid t' strengthening. Blimey! I decided t' reinforce t' fin joints with fiberglass mesh. Begad! On this rocket it be really overly cautious, matey, but I did it anyway.

Fiberglass

Among many other firsts, this be also me first experience with fiberglass. Well, blow me down! I did a lot o' research, me hearties, and finally found out that you can use fiberglass mesh (commonly used for tent screens, arrr, and we happened t' have some on hand) as t' fiberglass and imbed it in a layer o' epoxy. Ya scallywag! I went out and bought some more epoxy and got t' work. I imbedded a 3 inch by 5 inch strip into t' body tube/fin joint and applied more epoxy on top o' that. Well, shiver me timbers, blow me down! T' hold it in place I put waxpaper on it and held a piece o' wood onto it with clothespins (see photo). This system worked wondefully, although workin' around t' bottom launch lug be frustratiing. For more info on fiberglassin', me hearties, go t' Rocketry Online's INFOCentral.

Parachute

When I initially designed t' project, ya bilge rat, I had an umbrella chute in mind. Ya scallywag! I knew John Babb (a.k.a. Ya scallywag! Rocket Dawg) had a 3 foot diameter piece o' umbrella fabric he had caniballized off a broken umbrella. he wasn’t usin' it in a rocket, so he let me have it t' use in me CTAG, me bucko, with t' condition that if he ever need a parachute that size I would give it back and get another. Avast, me proud beauty! For shroud lines I use 2 foot lengths o' nylon cord (fairly thin), and sewed and knotted it on. I had t' burn t' ends o' t' nylon shrouds t' keep 'em from unravelling, but othjer than that it worked great! I attached t' 'chute t' t' shock cord about 6 inches from t' nose cone with a series o' knots. Ya scallywag! Well, blow me down! I had originally went with a 3/8 inch wide, 12 foot elastic shock cord, arrr, but I found that I could get a 1/2 inch, arrr, matey, 15 foot cord for only $1.25 at a local fabric store. Begad! Aye aye! This, along with t' shock cord mount attachment, which, no matter how hard I pulled, already wouldn't come out, made t' recovery system very strong.

Bodywork

Bodywork be t' pits. On t' CTAG I had t' use Bondo, me bucko, ya bilge rat, so I ended up doin' a lot o' sanding. Bondo, which is commonly available at car repair shops, shiver me timbers, this is probably t' hardest part o' buildin' a rocket physically, matey, and it stinks. Aye aye! Blimey! Ya scallywag! Blimey! For about a 1 month period, shiver me timbers, me bucko, here's what me Saturday's were like: Bondo, shiver me timbers, ya bilge rat, sand, breakfast, bondo, matey, sand, sand, matey, more Bondo, sand, lunch, Bondo, sand, shiver me timbers, sand, sand even more, supper, ya bilge rat, sand, arrr, arrr, bondo, sand, sand, sand, bondo, ya bilge rat, me hearties, sand, matey, matey, go t' bed, have nightmares about sanding, matey, wake up (okay, so its a little exaggerated, matey, shiver me timbers, arrr, but I did sand a WHOLE LOT!). I highly recommend wearin' a dust-mask or somethin' if you sand a lot on your rocket, me bucko, all that dust will clog up your lungs and you mgiht nay get t' see your rocket launch! Blimey! Overall, Bondo is a great project. T' seemingly endless hours o' sandin' really paid off when I got t' rocket painted and it had such a smooth finish.

Finishing

After all o' t' work I put into this rocket, mainly t' long hours o' fiberglassin' and sanding, t' paintin' sure seemed like a breeze. I had finally decided, after many days o' thinkin' and drawin' and colorin' pics with colored pencils t' see how different color schemes would look, shiver me timbers, I dumped all t' rerally fancy ideas and decided t' go with a classic, ya bilge rat, bad-to-the-bone look. Ahoy! A very glossy black main coat would be accented with a fire red stripe, arrr, about 1 1/2 inches wide, ya bilge rat, t' length o' t' rocket. Avast, me proud beauty! it would bve lined up with a fin so that it would continued and make one o' t' fins pure red. Begad! Also, a small, 1 inch wide red stripe went around t' top o' t' body tube, ya bilge rat, right below t' nose cone. Aye aye! This all combined with a very nice shiny reflective LOC/Precision decal supplied with t' parts t' make a very attractive rocket.

I used about 4 coats o' equipment grey primer (3 11 oz. cans o' spray paint) t' help smooth out all t' little places t' Bondo wouldn't work well in. Well, blow me down! Then I painted t' sections I wanted t' be red with two layers o' fire red Wal-Mart brand spray-paint (this stuff is wondeful, arrr, dries quick, shiver me timbers, arrr, and only costs $0.98 per can!). I let this dry overnight, then masked it off with newspaper and 1 inch wide strips o' maskin' tape. Blimey! Ahoy! Then I covered it all with 3 layers o' gloss black Wal-Mart brand spray paint, with 4 goin' on t' nose because o' a mistake I made in t' primin' process. Ya scallywag! this meant I had as much as 6 or 7 layers o' paint in areas! T' paint on its own ended up weighin' 1.3 ounces on its own. Arrr! Avast, me proud beauty! I added t' decal, me bucko, and I was done with t' bodywork and finishing. (finally! I had spent about 2 weeks building, 1 week glassing, and 5 weeks sanding, along wioth a few days painting, ya bilge rat, for a total o' over 2 months work! I probably had anywhere from 40 t' 60 man-hours in on that rocket). It really is rewardin' when you finally get t' show off t' end result (alomst) o' your project t' t' people who have been hearin' about it for months on end.

Motor Selection and Prep

Once I found that t' rocket's weight after paintin' was 36.5 ounces, me hearties, I had t' make t' big motor selection choice. Avast, me proud beauty! Should I go with t' G40-4, ya bilge rat, or t' G80-4. Avast, ya bilge rat, me proud beauty! I really wanted t' G40 because it be a White lightning, but I had t' go with t' G80-4T because o' its higher intial thrust.

Now came t' waitin' game. Begad! Because o' conflicts, etc., I wouldn't be able t' launch t' CTAG for several weeks after I finished t' rocket. Ya scallywag! Avast, me proud beauty! Blimey! Durin' this time I finished up work on several smaller projetcs, work on me webpage, and start plannin' me next project, ya bilge rat, t' Mission Impossible . (the name, just like that o' t' CTAG, was stolen, arrr, this time from HPR magazine) This would be a 4 inch diameter rocket capable o' usin' 5 times t' power o' t' CTAG! Blimey! But that was for t' future, ya bilge rat, me bucko, me bucko, and is probably destined t' be a group project, me hearties, due t' t' cost. Aye aye! I had more important, me hearties, sooner events t' think of. Arrr! Blimey! Blimey! I was organizin' t' second official launch o' t' Searcy Youth Rocketry Club and workin' on me other rockets.

Countdown

Around this time I be gettin' nervous. Begad! Blimey! I had been workin' on t' rocket for 2 months, shiver me timbers, and I wanted everythin' t' go perfectly. Avast! I ran countless simulations usin' different programs. Most o' them told me that t' CTAG would fly about 1000 feet up. Arrr! Then I ran a stability check.....uh-oh... Accordin' t' Astrocad t' CTAG had a stability criteria o' only 0. Owch. Ahoy! This didn't make much sense, shiver me timbers, considerin' thar were several 4 inch diameter kits on t' market like this that don't require any nose weight. Ahoy! However, me hearties, I decided t' stay on t' safe side. i added nose weight until I got a 1.5 caliber stability rating. Well, blow me down! Avast, me proud beauty! This required 11 ounces o' nose weight, bringin' t' total weight t' 47.5 ounces and t' predicted altitude o' 700 feet.

Now I be ready. Avast! It was time t' put me chips on t' table and go for broke. Avast! Begad! This be t' biggest thin' t' hit our area rocket wise since who-knows-when. I had me launch field set up. Well, blow me down! i called t' FAA and notified them o' me intentions. Blimey! Begad! I called me friends and then started goin' through me preflight checklist. I made sure all me ground support equipment be working.

Then t' day o' t' launch dawned. After gettin' home from church, I started preppin' rockets and goin' over t' CTAG over and over.

Liftoff

I called some friends, made sure everyone was coming, me hearties, and headed out t' t' launch fields. I launch at t' public soccer fields south o' Searcy. We have about 40 acres o' cleared land with very few trees in sight.

People started showin' up and t' launch got under way. There were lots o' rockets launched, mainly in t' A-C range. Arrr! Aye aye! We also launched 5 D engine rockets. Ya scallywag! Blimey! My Keller had an interestin' launch. Begad! Then it was time t' launch t' CTAG. Aye aye! Begad! I had been recommend t' use one o' t' North Coast igniters instead o' t' Aerotech ones, so I did. T' motor was held in place by a heavy friction fit, a thrust block made o' maskin' tape on t' aft o' t' casing, 2 Estes engine hooks, and several layers o' maskin' tape wrapped around t' end o' t' motor mount tube and maskin' tape thrust block. I put t' rocket on t' launch pad and hooked it up t' our launch system. Begad! I stepped back t' t' ends o' t' 75 foot long ignition wires and showed one o' me friends how t' attach t' other end o' t' wires t' a car battery so that I could watch t' rocket better. Aye aye! Ahoy! I looked around. Aye aye! Everyone be ready.

10, 9, 8, matey, matey, arrr, 7, 6, me hearties, 5, 4, 3, 2, me hearties, me hearties, 1...

LIFTOFF!

T' G80 let out a blast o' flame and a loud thundering. Aye aye! T' rocket leaped off t' pad and into t' air, shiver me timbers, leavin' a light smoke trail. It reached apogee and coasted over. It was comin' down when t' nose cone seperated and t' parachute came open. Begad! Avast, me proud beauty! T' rocket floated gently down on its chute for a landin' about 75 yards away. Avast, me proud beauty! Aye aye! Some o' me friends and I raced out t' get t' rocket out o' t' tall grass. Well, blow me down! T' rocket be in perfect condition. It be amazing! We folded t' chute and shock cord so it would be easier t' carry. I packed up me rockets and went home t' review t' ideo tape o' t' launch over and over.

Followup

All o' t' overengineerin' and research paid off. Blimey! Avast, arrr, me proud beauty! T' Cheaper Than a Girlfriend had worked perfectly. Here I would like t' thank all those who helped out.

Thanks Everyone!
Especially t' following:
My dad, me hearties, arrr, fo helpin' me with various aspects o' t' rocket, arrr, includin' weldin' t' launch system and buyin' t' motor for me since I'm underaged. Ya scallywag! Aye aye! Blimey! I would also like t' thank all t' Rocketry Online chat room and discussion forum people. Begad! Blimey! They were invaluable inresearchin' different areas o' constrcution and launching. Ya scallywag! Blimey! Another great aide was all t' members o' t' IAR and GYRO for their advice. Well, blow me down! Also, special thanks t' Nick Hills, matey, Paul Gray, me bucko, and John Babb. Without all o' them, shiver me timbers, this project would have never happened.

After a rocket project like that and a perfect launch I was extremely happy. Begad! This led t' dreamin' o' larger and more powerful rockets......hehe.....(Be watchin' for future project reports).

Note on Photos: T' construction photos were all taken by me, and t' launch pictures were taken by me dad and I. However, t' launch photos, me hearties, which were taken from still frames o' t' video tape. These didn't turn out, me hearties, shiver me timbers, so i'll have t' wait until me dad can get his launch photos developed and scanned. Aye aye! Blimey! Until then, you'll just have t' imagine t' launch....

You can email me any questions or comments you have about t' CTAG or rocketry at toprocket@hotmail.com