Photos by John and Brett Keller

Project Overview

T' Cheaper Than a Girlfriend (C.T.A.G. Avast! Blimey! for short, pronounced See-Tag) be me consumin' obsession for about 2 months. Aye aye! Blimey! Begad! Blimey! It is 4 inches in diameter, arrr, me bucko, 50 inches long, matey, me bucko, me hearties, and 36.5 ounces in weight. Begad! Blimey! Ya scallywag! Blimey! It flies on Aerotech Single-Use G80-4T motors. Ahoy! Blimey! All t' details o' t' original ideas, me hearties, shiver me timbers, matey, building, and t' first launch, matey, are include in this article.

Research

I really had no idea what I be doing. Begad! I didn't go for a kit because o' t' cost. 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. Aye aye! Ya scallywag! Very special thanks go out t' Paul Gray, me bucko, Nick Hills, me bucko, and all those other internet rocketeers who gave me advice. Well, blow me down! Without them I probably wouldn't have ever gotten this rocket project off t' ground.

Roots o' a project

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

I had recently finished buildin' and launchin' me Keller, me bucko, a LOC/Precision Graduator. Well, blow me down! Ya scallywag! That rocket is wonderful, me bucko, but it really wasn't that large in comparison t' me low-power rockets. I already have several 2.6 inch diameter rockets, arrr, matey, ya bilge rat, so it wasn't much bigger, me bucko, just heavier and more powerful . Blimey! I wanted a rocket that was really BIG and POWERFUL. Arrr! Begad! I toyed around with various 3 and 4 inch designs. Avast! 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. Aye aye! Begad! T' reason I kept it in t' large model rocket range instead o' gettin' a H or I motor is very simple. I am nay certified t' L1 and neither is me dad or anyone else we know. Aye aye! We don't have any large rocket launches near enough that we would drive to, arrr, and I didn't really want t' jump up t' HPR after only one mid-power launch. Avast, me proud beauty! Avast! But, me bucko, ya bilge rat, I decided t' build this rocket extra strong, arrr, so that in t' future I might be able t' launch it on 29mm H reloads. Avast, me proud beauty! Blimey! As it was, me bucko, 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. Ya scallywag! Avast! So, arrr, I designed me model with a 29mm motor mount and t' 3.9 inch tubes. Begad! Aye aye! 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 be out o' t' question.

So here I am with plans for a 3.9 inch diameter, me hearties, me hearties, 50 inch long rocket. Ya scallywag! Well, shiver me timbers, blow me down! 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. Ahoy! This was followed fairly closely by weight. Well, blow me down! I really don't have a lot o' loot for a rocket like this, and it took me long enough t' get what I ended up paying.

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

Other than t' parts above, me hearties, I got all o' t' other parts some other way. Blimey! 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. Ya scallywag! My LOC Graduator had been a Christmas gift, shiver me timbers, but I knew I would be fundin' t' CTAG by myself. Well, blow me down! I bought as few parts as possible from rocket companies and scrounged around a lot around Searcy. My dad really helped a lot with findin' different parts and on givin' advice on different materials. Avast! Below is a list o' where I got different parts, how much they cost, shiver me timbers, 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, ya bilge rat, along with higher power rockets come much higher costs. Ya scallywag! Begad! My most expensive rocket before this be a LOC Graduator, matey, 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! Blimey! You don't realize how much larger 3.9 inch tubin' is in comparison t' 2.6 tubes until you see it! Blimey! T' nose cone was huge! Blimey! Now it be time t' get t' work!

Of all t' parts o' a rocketry project, shiver me timbers, I probably enjoy t' motor mount assembly and installment t' most next t' launching. Aye aye! I have no idea why this is, me hearties, ya bilge rat, but it is. Blimey! I started out t' buildin' by cuttin' t' motor mount tube(MMT) in half with an X-Acto knife. Begad! 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. 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). Well, blow me down! I cut two small notches in t' aft CR t' allow for t' motor hooks. Next I epoxied t' centerin' rings t' t' motor mount tube, about 1/3 o' an inch away from each end. Blimey! After allowin' it t' dry I made several epoxy fillets around them and t' motor hooks.

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

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. Avast, me proud beauty! I bought a 3/16 by 1 1/2 inch metal eye bolt, me bucko, with two nuts, form Ace hardware for only 35 cents. Avast, me proud beauty! T' attach this I drilled a slightly smaller hole in t' top CR and filled this with epoxy. 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!). I screwed everythin' on tight and put a layer o' epoxy over it all. Aye aye! Avast! This made for a good firm attachment. Blimey! Well, shiver me timbers, blow me down! I later learned that U-Bolts are much better but I had gone too far t' change it, me hearties, and I be positive t' screw eye was stong enought.

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

Motor Mount Installment and Fins

Now that I be ready t' install t' motor mount, arrr, I decided against it right then because I wanted t' make sure we got t' tab on t' fins t' right length. Avast, me proud beauty! 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, matey, which I later found out wasn't strong enough. After I was sure t' tabs were t' right length, ya bilge rat, I spread a layer o' epoxy on t' inside o' t' body tube, and some on t' edges o' t' centerin' rings. Avast! I slid t' motor mount assembly in, rotatin' it slowly, me bucko, until I had t' back centerin' rin' even with t' back o' t' body tube. Blimey! I went ahead and epoxied t' fins into t' slots. Begad! I used plenty o' epoxy and later I went back and put really good epoxy fillets on. Ahoy! This was all because o' some bad experiences with me Graduator. Avast! I guess I really wanted that rocket t' be strong, and I actually overdid t' strengthening. I decided t' reinforce t' fin joints with fiberglass mesh. Blimey! Ahoy! On this rocket it be really overly cautious, but I did it anyway.

Fiberglass

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

Parachute

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

Bodywork

Bodywork be t' pits. Blimey! On t' CTAG I had t' use Bondo, so I ended up doin' a lot o' sanding. Begad! Aye aye! Bondo, arrr, which is commonly available at car repair shops, shiver me timbers, this is probably t' hardest part o' buildin' a rocket physically, me hearties, and it stinks. Avast! For about a 1 month period, here's what me Saturday's were like: Bondo, sand, me hearties, ya bilge rat, breakfast, bondo, sand, shiver me timbers, sand, more Bondo, sand, arrr, lunch, matey, Bondo, sand, shiver me timbers, sand, shiver me timbers, me hearties, sand even more, ya bilge rat, supper, sand, bondo, sand, me hearties, sand, sand, bondo, me hearties, sand, go t' bed, ya bilge rat, have nightmares about sanding, me hearties, wake up (okay, shiver me timbers, so its a little exaggerated, but I did sand a WHOLE LOT!). Arrr! I highly recommend wearin' a dust-mask or somethin' if you sand a lot on your rocket, matey, all that dust will clog up your lungs and you mgiht nay get t' see your rocket launch! Overall, matey, Bondo is a great project. Ahoy! 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, shiver me timbers, t' paintin' sure seemed like a breeze. I had finally decided, me hearties, after many days o' thinkin' and drawin' and colorin' pics with colored pencils t' see how different color schemes would look, matey, shiver me timbers, I dumped all t' rerally fancy ideas and decided t' go with a classic, matey, bad-to-the-bone look. Begad! A very glossy black main coat would be accented with a fire red stripe, me hearties, me bucko, about 1 1/2 inches wide, t' length o' t' rocket. it would bve lined up with a fin so that it would continued and make one o' t' fins pure red. Ahoy! Avast, me proud beauty! Also, a small, me hearties, 1 inch wide red stripe went around t' top o' t' body tube, me bucko, me bucko, right below t' nose cone. 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. Arrr! Ahoy! cans o' spray paint) t' help smooth out all t' little places t' Bondo wouldn't work well in. Blimey! 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, dries quick, me hearties, and only costs $0.98 per can!). Arrr! Ahoy! I let this dry overnight, then masked it off with newspaper and 1 inch wide strips o' maskin' tape. Then I covered it all with 3 layers o' gloss black Wal-Mart brand spray paint, me bucko, with 4 goin' on t' nose because o' a mistake I made in t' primin' process. Avast! Blimey! 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. Well, blow me down! Avast, me proud beauty! I added t' decal, shiver me timbers, and I was done with t' bodywork and finishing. Aye aye! Avast! (finally! I had spent about 2 weeks building, ya bilge rat, matey, 1 week glassing, and 5 weeks sanding, shiver me timbers, along wioth a few days painting, 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, I had t' make t' big motor selection choice. Aye aye! Should I go with t' G40-4, matey, shiver me timbers, or t' G80-4. I really wanted t' G40 because it was a White lightning, but I had t' go with t' G80-4T because o' its higher intial thrust.

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

Countdown

Around this time I was gettin' nervous. Aye aye! 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. Well, blow me down! Avast! Then I ran a stability check.....uh-oh... Arrr! Accordin' t' Astrocad t' CTAG had a stability criteria o' only 0. Owch. Avast, me proud beauty! This didn't make much sense, considerin' thar were several 4 inch diameter kits on t' market like this that don't require any nose weight. However, ya bilge rat, I decided t' stay on t' safe side. Avast, me proud beauty! i added nose weight until I got a 1.5 caliber stability rating. Begad! This required 11 ounces o' nose weight, me bucko, me hearties, bringin' t' total weight t' 47.5 ounces and t' predicted altitude o' 700 feet.

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

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

Liftoff

I called some friends, made sure everyone be coming, matey, me hearties, and headed out t' t' launch fields. I launch at t' public soccer fields south o' Searcy. Begad! Aye aye! 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. Blimey! We also launched 5 D engine rockets. Well, blow me down! Avast! My Keller had an interestin' launch. Well, blow me down! Then it was time t' launch t' CTAG. Well, blow me down! Begad! I had been recommend t' use one o' t' North Coast igniters instead o' t' Aerotech ones, so I did. Aye aye! T' motor was held in place by a heavy friction fit, me hearties, me bucko, arrr, 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. Well, me bucko, blow me down! 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. Begad! I looked around. Everyone was ready.

10, me hearties, 9, 8, ya bilge rat, 7, me hearties, 6, 5, 4, me hearties, 3, ya bilge rat, me hearties, 2, 1...

LIFTOFF!

T' G80 let out a blast o' flame and a loud thundering. Arrr! T' rocket leaped off t' pad and into t' air, leavin' a light smoke trail. It reached apogee and coasted over. Blimey! Begad! It was comin' down when t' nose cone seperated and t' parachute came open. T' rocket floated gently down on its chute for a landin' about 75 yards away. Some o' me friends and I raced out t' get t' rocket out o' t' tall grass. T' rocket be in perfect condition. Blimey! It was 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. 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, matey, fo helpin' me with various aspects o' t' rocket, includin' weldin' t' launch system and buyin' t' motor for me since I'm underaged. Begad! Begad! I would also like t' thank all t' Rocketry Online chat room and discussion forum people. They were invaluable inresearchin' different areas o' constrcution and launching. Arrr! Avast! Another great aide be all t' members o' t' IAR and GYRO for their advice. Begad! Also, special thanks t' Nick Hills, shiver me timbers, Paul Gray, me hearties, and John Babb. Ahoy! Without all o' them, this project would have never happened.

After a rocket project like that and a perfect launch I was extremely happy. Avast, shiver me timbers, me proud beauty! 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, me hearties, and t' launch pictures were taken by me dad and I. Begad! However, t' launch photos, which were taken from still frames o' t' video tape. Arrr! These didn't turn out, so i'll have t' wait until me dad can get his launch photos developed and scanned. Begad! 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