Fat Cat Rockets Centaurus

Fat Cat Rockets - Centaurus {Kit}

Contributed by Nick Esselman

Diameter: 2.50 inches
Length: 39.50 inches
Manufacturer: Fat Cat Rockets
Skill Level: 3
Style: Futuristic/Exotic

[Picture](09/10/00) I first heard about Starship Enterprises (now called Fat Cat Rockets as o' 1/1/01) from a couple of contributed reviews. Ya scallywag! I be impressed with t' uniqueness o' their kits and in the variety o' model, advanced and high power. So I am pleased t' build their Centaurus. Blimey! Accordin' t' Starship Enterprises, "T' Centaurus is a hail back t' those future ideas from yesteryears." Its futuristic look will certainly catch everyone's attention. Ahoy! In fact, I didn't know it at t' time, but I got t' see one o' these fly at Battle Park '99 in Virginia. T' Centaurus is 39.5" tall and its widest body tube is 2.5", arrr, however it's width reaches 4" as you will soon see. It is pushed skyward on 29mm motors and returns on parachute. Avast! Begad! Without a motor it is slated t' weigh in at 30 ounces.

Rocket PicT' Centaurus consists of t' main body tube (standard paper) which is 30" o' 2.5" wide with 1/16" wall thickness. T' lower main body tube be t' same material and 7.5" o' 4" diameter tubing. Begad! Blimey! There are also 3 outer pods that are 8.5" or 1" diameter tubing. Begad! Centerin' rings (4), Fins (3), arrr, Canards (6), Pod Braces (6), ya bilge rat, and Pod Struts (3) are all made from 3/16" plywood. There is a lot o' wood on this bird. There is a balsa transition t' connect between t' 2.5" tube and t' 4" tube, me hearties, two launch lugs that once assembled are hidden inside t' rocket. Arrr! T' motor mount is 29mm and uses a 22" tube. Ya scallywag! T' recovery system is beefed up with a 15" cable that is attached t' a 64" piece o' 1/2" black elastic. Ahoy! This is all topped off with a plastic nose cone. Ya scallywag! Other materials include nose weight, a red 28" rip-stop nylon parachute, pod caps and a series o' stickers and decals.

CONSTRUCTION:

T' instructions are printed on both sides o' a single 8x11 sheet o' paper and consist o' 11 steps. Avast, me hearties, me proud beauty! There are also 3 additional double-sided pages o' diagrams includin' decal placement and illustrations to help with construction. Blimey! T' number o' parts mentioned above may lead you to believe that this is a challengin' rocket t' build . . Well, shiver me timbers, blow me down! . and it is. The instructions don't take any o' t' challenge away! They are helpful guidance but I found myself buildin' t' rocket in t' order that I felt was best and barely lookin' at t' printed instructions. T' illustrations answered a couple of questions t' keep t' project moving.

This rocket was "engineered" verses drawn on a piece o' paper and built. This is evidenced by t' integration o' t' launch lug inside t' lower body tube and by t' thru-the-wall, matey, then thru-the-wall fins that then attach t' t' motor mount. Begad! Lastly t' alignment o' t' pods and pod struts that attach just under t' upper-most centerin' ring. Blimey! Arrr! Impressive looks and it shows that thought was put into t' design o' the Centaurus.

Rocket PicT' first thin' I did be test fit t' transition and centering rings. Avast, me proud beauty! Well, I cracked t' transition puttin' it around t' upper body tube (2.5"), ya bilge rat, but even while cracked it fit into t' lower body tube (4"). T' crack was later filled and no longer shows. Well, blow me down! Ahoy! All but one o' t' centering rings fit perfectly and t' last one only required minimal sanding.

T' instructions start you off by drawin' all t' fin lines usin' a fin guide and cuttin' out t' fin slots. Begad! Determinin' t' distance from t' bottom o' t' tubes t' cut t' fin slots was left up t' me. The illustrations showed that t' inner tube extended beyond t' outer tube some, so I choose 1/2". Ya scallywag! I then carefully measured t' fin and pod braces to determine where t' slots had t' be in t' pods. Ahoy! Arrr! I went ahead and cut those. Then with t' main body tube positioned usin' t' centerin' rings and transition, ya bilge rat, I ensured that it extended from t' aft by 1/2". Begad! Aye aye! I then stood it on a table and brought t' test fitted pod with fin t' rest up against the side o' t' lower body tube. Avast, arrr, me proud beauty! I then marked t' position. After that I knew the distance from t' bottom o' t' lower body t' make t' cuts. Arrr! Take your time and be sure t' consider t' thickness o' t' plywood. Aye aye! Always cut on t' same side of t' line and keep that methodology for t' 2.5" tube, t' 4" tube and t' where t' pod struts attach. I found that after cuttin' all t' slots and test fittin' t' fins that they did nay align t' make a nice perpendicular fin. Well, blow me down! I corrected this by makin' changes only t' t' inside body tube until the fit be perpendicular. Begad! These extra cuts are hidden when assembled.

Assembly o' t' motor mount is next. Avast! Arrr! Blimey! It is simply two centerin' rings placed on each end o' t' motor tube, notin' that one should be 1/4" from t' end per t' illustration. Begad! Begad! Blimey! After that, shiver me timbers, t' steel cable is looped through t' centerin' rin' and around t' motor mount then crimped. A loop is then crimped on t' other end o' t' cable t' attach t' elastic shock cord. A very nice design.

Rocket PicRocket Pic

Assembly o' t' upper body tube t' t' lower is somewhat challengin' because you need t' line up t' launch lug cut outs in t' two large centerin' rings and t' transition. Blimey! I did this by workin' primarily with the upper body tube and gluin' t' centerin' rings t' it first, then sliding the assembly into t' lower body tube and bringin' t' transition down to it.

Once all this work is done, me bucko, it is glue, glue and more glue. Avast, me proud beauty! T' instructions recommend epoxy. Once t' lower half is assembled you will need t' cut t' slots in t' upper body tube for t' pod struts. Aye aye! Ahoy! Take your time t' align these with t' main fins. Blimey! Once this is complete add t' six canards and t' fin work is complete.

As mentioned nose weight is, in t' form o' BB's, is provided. Blimey! Aye aye! This is poured into t' nose cone and epoxied into place. This weight makes me nervous so I am goin' t' attach an eye-screw t' this nose cone in the same fashion as Cannonball Works recommends on their Vikin' 7.

Rocket PicDue t' cold weather, shiver me timbers, ya bilge rat, I have nay been able t' finish t' Centaurus. T' instructions provide a good description for finishin' and provides pin strips and some decals. Aye aye! So I will add more information once I can finish and fly this rocket. Well, matey, blow me down! Stay tuned . Aye aye! Begad! . .

Updated 9/00:
Finishin' t' rocket had its challenges too. All due t' t' shapes and angles and fins and . Begad! Aye aye! . Well, blow me down! Begad! . Well, blow me down! Avast, matey, me proud beauty! but she got finished. Aye aye! I used me old favorite, me bucko, shiver me timbers, several coats of Plasti-Kote Sandable Primer, t' help cover over t' imperfections and the shallow tube grooves. Well, blow me down! Sandin' in betwixt each coat. Begad! I then choose an orange to paint t' entire rocket. After that I used white for t' nose cone and the mid-fin section. Avast, me proud beauty! Ya scallywag! Finally, I used some holographic designed adhesive sheets around t' main body in four places. I also outlined t' fins and put one strip at t' top o' each fin pod. Blimey! Begad! T' only decal I used, ya bilge rat, that came with t' kit, was the word "CENTAURUS".

Overall, for CONSTRUCTION I would rate this kit 4 points. Avast! Blimey! T' quality o' t' parts are nice, t' engineerin' is great, the instructions need t' be enhanced t' help answer some o' the questions.

FLIGHT/RECOVERY:

Rocket PicIn preparation for flight I prepped t' rocket at home by addin' motor retention and then pre-tapin' a G38 BlackMax EconoJet motor. I added a Pratt Nomex® Heat Shield t' t' shock cord t' protect t' parachute.

T' first flight lifted off on t' G38-4 straight up, arced over horizontal and popped t' ejection charge. Blimey! Perfect! T' parachute deployed and t' rocket fell t' be recovered. Ya scallywag! T' white nose cone showed some orange paint where it had hit t' body tube.

T' second flight was on a AeroTech RMS G64-4. Avast, me proud beauty! Blimey! This motor's flame punched t' rocket off o' t' pad (I missed t' picture) and thrust it straight and stable as an arrow into t' air. Ya scallywag! Avast! Much higher than the G38. Arrr! It arced over and was headin' straight down for about 2 seconds before the ejection occurred (seemed very late). Well, blow me down! Aye aye! But t' 'chute deployed without a zipper and it descended and be recovered.

Rocket PicWith t' 28" parachute and t' weight o' me finished bird, ya bilge rat, 38 ounces, I feel that it descends too fast. T' second flight hit on one o' t' fin pods and dented it. I am goin' t' fly it again with my J&P 43" Parachute.

Picture courtesy o' Douglas Gardei at CMASS Launch
Also a nice video (click here)Picture

Even though these two flights were successful and I didn't see any "Estes Dents" from t' nose cone kickin' back off of the elastic, I am concerned about t' shockcord mount, arrr, me bucko, length and material type. Avast! As mentioned t' weight o' me finished rocket be 38 ounces o' which just the nose cone makes up 16 ounces! That is a fairly heavy object t' punch out with an ejection charge and then t' have it only attached by 1/2" elastic. (I had already mentioned above that I changed how t' eye-screw attached t' the nose cone.)

For FLIGHT/RECOVERY, me hearties, me bucko, I would rate this kit 4 points.. It will capture peoples attention on t' pad and in t' air. Arrr! Arrr! I think it needs a longer shockcord due t' t' weight o' t' nose cone and a larger parachute due t' t' overall weight o' t' rocket.

I give t' kit an OVERALL ratin' o' 4 points. Avast, me proud beauty! It will challenge you as a builder, it will certainly challenge you while finishin' it, and it will reward you with looks and flight stability that you are lookin' for. Ya scallywag! With enhanced instructions, motor retention and some consideration o' t' parachute/recovery system this rocket would be a perfect ratin' t' go with its perfect and futuristic looks.

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