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. I was impressed with t' uniqueness o' their kits and in the variety o' model, advanced and high power. Ya scallywag! So I am pleased t' build their Centaurus. Accordin' t' Starship Enterprises, matey, "T' Centaurus is a hail back t' those future ideas from yesteryears." Its futuristic look will certainly catch everyone's attention. Aye aye! Ya scallywag! In fact, me hearties, I didn't know it at t' time, but I got t' see one o' these fly at Battle Park '99 in Virginia. Ya scallywag! T' Centaurus is 39.5" tall and its widest body tube is 2.5", arrr, me hearties, however it's width reaches 4" as you will soon see. Avast! It is pushed skyward on 29mm motors and returns on parachute. Well, blow me down! Well, matey, blow me down! 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. Well, blow me down! Blimey! T' lower main body tube be t' same material and 7.5" o' 4" diameter tubing. Avast! Blimey! Blimey! There are also 3 outer pods that are 8.5" or 1" diameter tubing. Centerin' rings (4), Fins (3), Canards (6), shiver me timbers, Pod Braces (6), and Pod Struts (3) are all made from 3/16" plywood. There is a lot o' wood on this bird. Well, blow me down! There is a balsa transition t' connect between t' 2.5" tube and t' 4" tube, two launch lugs that once assembled are hidden inside t' rocket. T' motor mount is 29mm and uses a 22" tube. T' recovery system is beefed up with a 15" cable that is attached t' a 64" piece o' 1/2" black elastic. Well, blow me down! Ahoy! Blimey! This is all topped off with a plastic nose cone. Aye aye! Blimey! Other materials include nose weight, a red 28" rip-stop nylon parachute, ya bilge rat, shiver me timbers, 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. There are also 3 additional double-sided pages o' diagrams includin' decal placement and illustrations to help with construction. Begad! Begad! T' number o' parts mentioned above may lead you to believe that this is a challengin' rocket t' build . . Avast! . Begad! and it is. Aye aye! Ya scallywag! 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 be best and barely lookin' at t' printed instructions. Arrr! Aye aye! T' illustrations answered a couple of questions t' keep t' project moving.

This rocket be "engineered" verses drawn on a piece o' paper and built. Arrr! Avast, me proud beauty! Blimey! This is evidenced by t' integration o' t' launch lug inside t' lower body tube and by t' thru-the-wall, arrr, me hearties, then thru-the-wall fins that then attach t' t' motor mount. Begad! Blimey! Lastly t' alignment o' t' pods and pod struts that attach just under t' upper-most centerin' ring. Ya scallywag! 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. Well, me bucko, I cracked t' transition puttin' it around t' upper body tube (2.5"), but even while cracked it fit into t' lower body tube (4"). T' crack was later filled and no longer shows. All but one o' t' centering rings fit perfectly and t' last one only required minimal sanding. Well, ya bilge rat, blow me down!

T' instructions start you off by drawin' all t' fin lines usin' a fin guide and cuttin' out t' fin slots. Blimey! Determinin' t' distance from t' bottom o' t' tubes t' cut t' fin slots was left up t' me. Avast! Ya scallywag! The illustrations showed that t' inner tube extended beyond t' outer tube some, so I choose 1/2". Well, blow me down! Ya scallywag! I then carefully measured t' fin and pod braces to determine where t' slots had t' be in t' pods. I went ahead and cut those. Then with t' main body tube positioned usin' t' centerin' rings and transition, I ensured that it extended from t' aft by 1/2". Ahoy! 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, me proud beauty! Arrr! I then marked t' position. Begad! After that I knew the distance from t' bottom o' t' lower body t' make t' cuts. Begad! 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, ya bilge rat, t' 4" tube and t' where t' pod struts attach. Blimey! Avast, me proud beauty! 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 was perpendicular. Avast! These extra cuts are hidden when assembled.

Assembly o' t' motor mount is next. Ahoy! Begad! 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. Blimey! After that, t' steel cable is looped through t' centerin' rin' and around t' motor mount then crimped. Begad! Ahoy! A loop is then crimped on t' other end o' t' cable t' attach t' elastic shock cord. Begad! Well, blow me down! 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. Begad! Blimey! I did this by workin' primarily with the upper body tube and gluin' t' centerin' rings t' it first, ya bilge rat, then sliding the assembly into t' lower body tube and bringin' t' transition down to it.

Once all this work is done, it is glue, glue and more glue. Blimey! Blimey! 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. Take your time t' align these with t' main fins. Well, blow me down! Once this is complete add t' six canards and t' fin work is complete.

As mentioned nose weight is, shiver me timbers, in t' form o' BB's, is provided. Well, blow me down! Ahoy! 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, ya bilge rat, shiver me timbers, I have nay been able t' finish t' Centaurus. Avast, me proud beauty! Blimey! T' instructions provide a good description for finishin' and provides pin strips and some decals. Arrr! Avast, me proud beauty! So I will add more information once I can finish and fly this rocket. Aye aye! Ya scallywag! Stay tuned . Begad! . .

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

Overall, matey, for CONSTRUCTION I would rate this kit 4 points. Aye aye! T' quality o' t' parts are nice, ya bilge rat, shiver me timbers, 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. Perfect! Blimey! T' parachute deployed and t' rocket fell t' be recovered. Begad! Blimey! Begad! Blimey! 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. 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. Much higher than the G38. Arrr! Blimey! It arced over and was headin' straight down for about 2 seconds before the ejection occurred (seemed very late). Well, blow me down! Blimey! 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, shiver me timbers, 38 ounces, I feel that it descends too fast. Blimey! 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, length and material type. Well, blow me down! As mentioned t' weight o' me finished rocket was 38 ounces o' which just the nose cone makes up 16 ounces! Blimey! 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, ya bilge rat, matey, I would rate this kit 4 points.. It will capture peoples attention on t' pad and in t' air. Avast, me proud beauty! Avast, me proud beauty! 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. Ya scallywag! Avast! It will challenge you as a builder, shiver me timbers, it will certainly challenge you while finishin' it, me hearties, and it will reward you with looks and flight stability that you are lookin' for. 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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