Yank Enterprises Black Brant X (3")

Yank Enterprises - Black Brant X (3") {Kit}

Contributed by Jon Hatch

Manufacturer: Yank Enterprises
Rating
(Contributed - by Jon Hatch - 08/10/02)

Pic Courtesy o' YankRocket Pic

Materials:
All parts were accounted for, except for a Yank Enterprises decal, arrr, which was advertised but nay included. Begad! As this was a scale rocket, shiver me timbers, me hearties, I had no intention of usin' it anyway, arrr, matey, so this be no loss. Ya scallywag! Begad! T' kit consisted o' 2 lengths o' 3" flexible phenolic body tube (34" & 31" long), one o' them slotted for t' aft fins. Aye aye! T' forward BT was supposed t' be marked for t' forward fins per t' included instructions, but was nay (no big deal, arrr, as it's nay that difficult t' make a fin guide with any graphics program). Begad! Arrr! Also included were 1 30" ripstop nylon parachute, shiver me timbers, 20 feet o' 9/16" tubular nylon, 2 quick-links, 2 eyebolts w/ washers, ya bilge rat, tube coupler, one birch ply bulkhead, 2 baltic birch ply centerin' rings, a 38mm motor mount, ogive nose cone, and 8 1/8" 5-ply baltic birch fins. Avast, me proud beauty! A couple o' t' aft fins were slightly warped, arrr, but I attribute this t' t' kit probably sittin' in t' hobby store basement for a considerable amount o' time, as t' maskin' tape also left marks that no amount o' sandin' would remove. Avast! Aye aye! All parts were very high quality and fit well together, me bucko, although with an assembled weight o' 60 oz, me bucko, I thought 3/16" or 1/4" ply would have been more appropriate for t' aft fins, as they sweep back past t' aft end o' t' rocket.

Materials score: 4 out o' 5
Pros: Very sturdy BTs and nice hardware
Cons: Aft fins are a little thin and t' parachute might be a size small (the website says they now ship 36" chutes) for t' weight o' t' rocket. Begad!

Construction:
Instructions were thorough if small, with one exception. Arrr! They did nay specify at t' appropriate step exactly how far forward from t' BT junction t' put the forward fins. Begad! Avast, me proud beauty! Blimey! I guessed at 1" and after lookin' at t' scale finishing directions, shiver me timbers, I believe this t' be correct. I decided t' go with an anti-zipper design as detailed in InfoCentral on Rocketry Online, matey, which changed my construction considerably from t' directions.

I drilled eight 5/16" holes in t' bulkhead, arrr, ya bilge rat, which was pre-drilled for the eyebolt assembly. I attached t' eyebolt assembly (washers were included) and epoxied it into t' coupler tube with a heavy fillet around t' outside.

T' forward BT needed t' be slotted, and took a bit o' time, as thar are a lot o' layers t' cut and peel. Begad! Since I would be cementin' t' coupler t' the lower BT instead o' t' upper, shiver me timbers, I cut t' slots a touch short and pushed the fins through t' back in order t' get a very tight fit before runnin' fillets along t' outside joints with 30 min epoxy.

On t' t' motor mount. Ahoy! Blimey! After cementin' t' forward centerin' rin' 1/4" from t' front o' t' MMT as directed and cementin' it t' t' BT, shiver me timbers, I realized that I should have gotten a 3rd centerin' rin' t' add right in front o' the fins. Begad! Blimey! Blimey! Blimey! T' instructions said t' cement t' aft centerin' rin' immediately and to simply run a bead o' epoxy t' t' fin root in order t' affix t' fins t' the MMT. I chose t' run fillets instead and held off on cementin' t' aft centering rin' until that be done. Since I didn't have a CR at t' front o' t' fins to serve as a dam for t' forward end o' t' fillets, I used 5 min epoxy for the internal fillets. Avast, me proud beauty! Blimey! I then used 1.5 oz glass t' reinforce t' fins and ran some very heavy outside fillets usin' 30 min. Aye aye! Blimey! Blimey! Blimey! epoxy. Begad! Blimey! Avast, me proud beauty! Blimey! Blimey! Blimey!

After puttin' blind T-nuts in for retention, me hearties, I saw that I didn't have a whole lot o' room t' fillet t' aft centerin' rin' t' both t' MMT and the outer BT, me bucko, so I decided t' just go with an epoxy well. Begad! T' protect t' T-nut opening, shiver me timbers, instead o' usin' tape and redrillin' through t' epoxy, I cut some plastic drinkin' straws down t' size, me hearties, fitted them over t' mountin' screws and screwed them down until t' straws were snug against t' threads. Ya scallywag! Avast, me proud beauty! Once the epoxy set, shiver me timbers, me hearties, it was easy t' simply pull t' straws out, shiver me timbers, leavin' a hole for the mountin' screws. Ahoy! Ya scallywag!

Then, me bucko, arrr, I cemented t' coupler t' t' aft BT with t' bulkhead facin' forward. Since I be usin' t' nosecone for t' forward end o' t' shock cord, I covered the other eyebolt with epoxy and inserted it into t' hole in t' bottom o' the NC. I then cut a hole in t' shoulder o' t' NC and used a syringe t' insert an epoxy well, which I hoped would ensure that t' eyebolt stayed in place. Aye aye!

Now, me hearties, this kit has a very interestin' method for attachin' your shock cord to the eyebolt. Well, blow me down! Blimey! T' instructions recommend loopin' t' cord through t' eyebolt and back onto itself (I did this on t' nosecone end). Ya scallywag! Then, shiver me timbers, approximately 4" o' overlap is completely saturated with 30 min epoxy and wrapped with tape. Arrr! I chose electrical tape for this process and it comes out very strong. Another loop at t' other end is completed and will be hooked onto a quicklink at t' other end. Since I wasn't goin' t' be modifyin' this kit any further, I sanded t' nosecone shoulder and epoxied it t' t' top o' t' rocket. Avast! Avast, me proud beauty! A quicklink on t' bulkhead eyebolt and on t' parachute complete t' recovery harness. Begad! Rail buttons were substituted for t' enclosed launch lugs, me bucko, me bucko, as I was told it's easier t' get a rail than t' right size rod at a launch. Ya scallywag!

Construction score: 4 out o' 5
Pros: Everythin' fits well together.
Cons: Slottin' flexible phenolic with a hobby knife isn't me idea o' fun. Begad!

Finishing:
I had filled t' spirals with cheap spackle prior t' construction, me hearties, so all that was needed at this point was several layers o' gray Krylon primer t' fill in what t' spackle missed and a coat o' white Krylon primer on top t' guard against colors darkening. Well, blow me down! Blimey! Due t' t' thickness o' t' flexible phenolic BT, there be a little additional fillin' t' be done from t' top o' t' BT t' the nose cone prior t' priming. All o' this was easily accomplished, matey, and t' primer took readily t' all sanded surfaces. Krylon paint was then used throughout for a scale paint job that drew several compliments at t' launch site. Avast, me proud beauty! Blimey! Blimey! Blimey! Gotta love Krylon! Blimey! You really have t' work at it t' make that stuff run. Aye aye! Blimey!

Finishin' score: 5 out o' 5
Pros: T' scale paint scheme is really neat and is a crowd-pleaser.
Cons: Slight fillin' needed betwixt t' nosecone and t' body tube. Ahoy! Begad!

Construction Rating: 4 out o' 5

Pic Courtesy o' YankRocket Pic

Flight:
T' model weighed in at t' launch almost exactly at 60 oz. Avast! Blimey! dry, even with the 45" chute that I substituted for t' 30" enclosed chute and a Transolve TransBeep as well. Ya scallywag! Blimey! Well, this be me Level 1 certification flight on an H242T, ya bilge rat, ya bilge rat, as well as me first "real" project beyond Aerotech, matey, so needless t' say I had plenty o' nerves here. Begad! Blimey! There was a slight wind (maybe 5 mph) which seemed t' be slightly affectin' most o' t' flights that morning. Since t' anti-zipper design caused about 4 margins o' stability with t' motor loaded, me hearties, me bucko, arrr, I decided t' launch vertically t' minimize weathercockin' instead of savin' myself a walk. Well, blow me down! Blimey! When t' button be pressed, shiver me timbers, me bucko, matey, t' rocket went perfectly vertical, with zero weathercocking. Begad! Blimey! Deployment was perfectly at apogee on a 10 second delay. RockSim said this would be at about 1700 feet at this weight and with t' modifications, but it honestly looked higher than that. Begad! Blimey! Since I was a little paranoid about t' drag separation and deployment, I placed t' chute about 6 feet from t' aft part o' t' rocket, which I think may have been a mistake. Avast! Blimey! I suffered some minor fin damage, arrr, which, I now believe may have been due t' t' front end o' t' rocket hittin' t' fin durin' deployment. Well, blow me down! Blimey! All told, it be a fantastic flight, and was good for me level 1. Begad! Blimey!

Pros: Straight as an arrow in t' slight wind
Cons: Can't really think o' any.

Flight Rating: 5 out o' 5

Summary:
This thin' builds like a tank, despite bein' as long as it is. Aye aye! Avast, me proud beauty! Flies beautifully on t' 242 and I can't wait t' up it a touch t' t' I357. Arrr! This is a great certification kit, me hearties, despite its length, as it's tough as nails with a little fin reinforcement. Aye aye! Avast! Had I nay cemented t' nose cone in, me hearties, I would wager that it could be modified for dual deployment and easily stand up t' a level 2 flight as well. Ya scallywag!

Overall Rating: 5 out o' 5

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