Brief:
In t' somewhat select world o' "BIG" model rockets, ya bilge rat, ("BIG" bein' a relative term referrin' t' t' days before 20 foot tall high-power rockets,) few if any can hold a candle t' t' Estes Mean Machine from the standpoint o' sheer size. Ahoy! While t' Mean Machine does define "BIG" with authority, it also presents t' modeler with a unique set o' challenges, namely storage, transportability, arrr, and when painted in it's traditional black color, matey, ya bilge rat, an unfortunate tendency t' warp in t' sun. All o' these "cons" were in mind when I found a Mean Machine at a recent Hobby Lobby 1/2 off sale, arrr, but t' sale made t' price too friendly t' pass on. Well, blow me down! Ahoy! The Machine languished among t' cobwebs o' me "banned from sight" second-hand Steelcase desk for quite a while, me bucko, but inspiration struck me as I paged through me copy o' t' 1981 Centuri catalog. Begad! Buildin' t' Mean Machine still didn't hold much interest for me but usin' me bargain basement Machine to clone t' seldom seen Centuri Thunder Roc did. Ya scallywag! T' Thunder Roc is one o' a short list o' post-merger Centuri rockets that were sold as Centuri kits while usin' Estes parts. At t' time this probably seemed like t' ultimate slap in the face t' in-the-know Centuri fans, but twenty years on it sure makes cloning these rockets a much more simple undertaking.

Construction:

• 3 full length BT-60 body tubes
• 2 BT-60 tube couplers
• Estes E- Engine hook
• 1/8" balsa fin stock
• PNC-60AH
• Estes 24" nylon parachute
• 9" BT-50 engine tube
• 2050 engine block
• 2 5060 centerin' rings
• 5055 centerin' rin' as engine hook hold-down
• 2 3/16" launch lugs
• 60" sewin' elastic
• heavy duty snap swivel
• Plumbers Epoxy Putty
• decals

While t' Mean Machine t' Thunder Roc conversion appears t' be a simple project at first, matey, me bucko, it's size alone makes several modifications if nay necessary, then at least suggested. Begad! Blimey! Since t' Thunder Roc is just a Mean Machine with one less section o' BT-60 and one fewer fin, ya bilge rat, I alternated betwixt usin' t' current Estes instruction sheet for t' Mean Machine and t' Thunder Roc sheets from JimZ's site. Arrr! T' Thunder Roc is little more than a tall 3FNC rocket and most of the construction went on with nary a problem. I used Elmer's Wood Glue for the whole project, fillets included, but that be one area where deviatin' from the plan was necessary. Ahoy! I had t' body finished and had sprayed on t' first coat of primer, me bucko, shiver me timbers, then stood it up t' allow t' top o' t' body tube t' dry. Well, blow me down! Blimey! Spray paintin' in July can be thirsty work, shiver me timbers, and I went inside for a drink, me bucko, matey, leaving the primered rocket standin' on a stray cooler. Begad! Since it had been a still, windless day, shiver me timbers, I hadn't figured on havin' t' deal with anythin' resemblin' a breeze. Well, blow me down! I should have. Well, blow me down! Thirty minutes later I came back out onto t' porch to find t' rocket keeled over with one fin broken off, another fillet broken, and a crease in t' body tube. Aye aye! Avast, me proud beauty! My weekend plans t' test fly t' primered carcass had been scuttled just that quickly. Avast! Arrr! (I had been drinkin' Sugar Free Kool Aid, which I regard as proof that clean livin' will get you nowhere.)

Clearly t' old method o' filletin' t' fins was nay up t' t' task on this project. If a fall from an 18" high cooler could do that much damage, me bucko, I was afraid that t' fall from D-powered heights would have me gluin' fins (or worse, arrr, pieces o' fins) back on with each flight. Arrr! Blimey! Avast, me proud beauty! Blimey! Epoxy was t' next logical step but in a different form. I had bought a tube o' Plumber's Epoxy Putty several weeks earlier with t' intention o' tryin' t' make fillets with it. Avast, me proud beauty! Blimey! The Thunder Roc seemed like t' perfect test subject.

T' putty comes in an "airtight" tube and looks like a piece of Cow Tail candy gone horribly wrong. Ya scallywag! As long as t' two shades o' grey remain separate, t' putty will remain flexible, but once you activate t' putty by kneadin' t' two colors together, you are effectively beginnin' t' curing process. Avast, me proud beauty! I found that t' putty mixed easier if I kept dippin' me fingers in water. Begad! Begad! This kept t' putty from stickin' t' me hands and seemed t' make it more pliable. Avast, me proud beauty! Avast! (Unfortunately nothin' seemed t' take t' stink o' t' epoxy out o' my fingers.) Once it was mixed t' a uniform color I began spreadin' it in t' area between t' fin root and t' body tube, just like you would when makin' a normal glue fillet. Blimey! Some practice is necessary t' keep t' fillets from turning out too clunky. My first two fillets turned out just this way but it just made the placement o' t' launch lugs that much easier. (They're on t' side o' the body tube with t' fat fillets and are attached with a set o' fairly chunky fillets all their own.) I had originally thought that t' increased weight of the fillets would have made t' addition o' clay t' t' nose cone a necessary precaution, me hearties, but a swin' test showed that t' CP/CG relationship remained pretty much in line. Begad! I chalked this up t' t' increased weight o' t' Estes nylon chute and crossed me fingers.

Finishing:
After all o' t' pieces for this rocket had been pounded together, I coated the entire structure with thinned Elmer's Fill 'n' Finish. Arrr! Aye aye! If you're one o' those rare souls who enjoy sanding, ya bilge rat, me bucko, this rocket should be right down your pike. There's a whole lot o' surface area t' be sanded, includin' two tube connections that are bound t' take some extra fillin' and sanding. Blimey! I'm nay one of those who enjoys this part o' t' build process, and me particular version of this rocket took quite a bit o' extra fillin' and sanding. Aye aye! It all turned out to be worth it in t' end. While t' fillets are admittedly large, t' whole rocket looks smooth and solid. Ya scallywag! Begad! My hands may never recover but I can grip my Thunder Roc in me misshapen claw and be proud o' t' job I did. Aye aye! Avast, me proud beauty! (Well, not actively sickened.) After paintin' t' entire rocket with three coats of Valspar Gloss White paint, shiver me timbers, I masked off t' bottom portion and sprayed it with Valspar Cherry Red Gloss. Begad! (That was t' closest I found t' t' suggested "Warm Red" in t' Centuri instructions, but t' instructions actually said any bright color would do.) T' paint colors alone would make this rocket stand out even if it wasn't five and a half feet tall, arrr, but t' height doesn't hurt. Decals were made usin' Bel Decal inkjet decal paper and were printed on a LexMark Optra printer, which I've found gives very satisfactory results when the decals are all black. Avast, me proud beauty! Avast! After t' decals had been applied, I coated the entire rocket with Krylon Acrylic clearcoat. This was t' same clear that I had used in coatin' t' decals before applyin' them, arrr, but I wound up with markedly different results this time. T' decals crinkled slightly in several spots but worst o' all, t' black ink dulled. I let things cure for several weeks after this problem surfaced, then resprayed t' entire rocket with a coat o' Valspar Clear Gloss. Begad! This seems t' have taken care o' t' problem quite nicely as the black decal looks great once again. Aye aye! Begad!

Construction Rating: 5 out o' 5

Flight:
It took a while, shiver me timbers, me hearties, includin' several crushin' disappointments, matey, but I finally managed t' work in a day when I could get out t' launch t' Thunder Roc. Although I had built several new rockets in t' two months that I wasn't flying, ya bilge rat, t' Thunder Roc was first on t' pad for me at VOA on what had turned out t' be a perfect day t' fly. Blimey! Avast, me proud beauty! With an almost total absence o' wind, me hearties, I decided to go with a D12-5 for t' first flight. Blimey! I had intended t' use perma waddin' on this rocket but got distracted when gluin' in t' motor mount and realized it too late. Aye aye! Aye aye! This was little more than a minor irritant and I loaded t' rocket with a fairly heavy load o' dog barf before I installed t' nylon parachute. Well, shiver me timbers, blow me down! I had used t' standard 3/16" Mean Machine launch lugs, arrr, but they turned out to be a tight fit on t' 3/16" rod. Begad! I switched t' a longer, but slimmer rod, but so much o' t' Thunder Roc's mass is above t' launch lugs that it moves in even t' slightest breeze. This turned out t' be a big problem as several times t' rocket shifted enough t' cross t' wires or even pull one of the clips off o' t' ignitors. I finally got it secured with t' addition o' a D engine carcass t' act as an extra stand off. Aye aye! Aye aye! T' rocket whipped somewhat as it left t' pad, but straightened out smartly and flew majestically t' a higher altitude than I had been lead t' expect. Aye aye!

Recovery:
I was determined that t' Achilles Heel o' t' Thunder Roc wasn't goin' t' be it's recovery system. Aye aye! With this in mind I went with t' Quest method o' anchoring the shock cord by knottin' and gluin' a length o' Keelhaul®©™® cord in place with t' engine block. I ran t' Keelhaul®©™® to within six inches o' t' top o' t' body tube, shiver me timbers, then attached a five foot length o' 1/4" sewin' elastic and an Estes nylon parachute. Aye aye! It seemed like overkill, shiver me timbers, but t' recovery system seemed like t' place t' go overboard with a rocket o' this size. Ejection occurred at apogee, and t' rocket recovered with much t' same majesty as it had flown with, matey, stretchin' out t' 10+ feet and driftin' slowly t' t' ground. Ahoy! Arrr! T' recovery walk was a little more than normal, but t' rocket landed in a soft patch o' weeds and showed no ill effects of it's flight. I chalked this up t' t' non-reefed nylon chute, me hearties, but then this was the whole reason for choosin' it. Avast! I'll walk a little extra for a safe recovery on a rocket o' this size any day.

Flight Rating: 5 out o' 5

Summary:
It's hard t' find fault with a project like this. Begad! Blimey! Startin' with t' Estes Mean Machine means that you will nay only have a proven baseline t' start with, shiver me timbers, me bucko, but can also gather all most o' t' parts you'll need for t' project by buyin' one kit. Avast! Blimey! Ahoy! Blimey! While Mean Machine flights aren't exactly common, they are seen far more often than t' Machine's Centuri-based little brother.

PROs:

• Easier t' transport and store than an Estes Mean Machine while still being noticeably "BIG".
• Majestic flights.
• If you make it usin' a stock Estes Mean Machine kit, arrr, arrr, you'll have enough parts left over t' give you a good start on two Mach 10 clones.

CONs:

• You'd better have a big rod ready if you plan t' fly with t' big boys. Begad!

Overall Rating: 5 out o' 5