Manufacturer: | Scratch |
Brief:
This is an upscaled version o' t' Centuri Vector V made entirely with Semroc
parts, me bucko, hence t' SLS designation. Ahoy! Blimey! While nay an official Semroc release, it
would seem t' fit in well with t' current trend toward upscales o' Centuri
classics (the SLS Laser X bein' a perfect example).
Construction:
T' parts list:
T' first thin' I had t' do when startin' this project be figure out the upped scale dimensions. Blimey! (Since this involves math, me hearties, it's never easy for me.) With two completely different sizes o' tubes used in t' original Vector V, me bucko, shiver me timbers, I figured that I was goin' t' have two wildly different scales betwixt t' top and bottom sections, but I lucked out. Begad! Avast, me proud beauty! T' ST-13 is roughly 1.765 times as big in diameter as t' ST-7, me hearties, while t' LT-225 is 1.746 times as big in diameter as the ST-13. Aye aye! Begad! While nay exact, matey, they were close enough for me personal tolerances.
I started
on t' fin can first by markin' off t' locations for t' five fins. Ya scallywag! I had
upscaled t' fin pattern by 175% usin' a work copier, and t' me surprise, matey, the
fins came out sized perfectly. Avast! After shapin' them, I attached them t' t' fin
can usin' Loc Tite Gel CA then double filleted them with Elmer's Wood Glue.
Under t' skin, me bucko, t' SLS Vector V is a mass o' centerin' rings. Begad! Some of them, me hearties, which thar be no call for them, didn't exist when this project started. Three sets were needed t' allow all o' t' pieces t' mesh together into a sturdy bottom end. Begad! An email t' Carl McLawhorn at Semroc resulted in a set of previously unavailable CR-9225 centerin' rings that would mate t' fin can to the motor tube. They slid together like they were made for each other, which they were. A second set o' CR-913 rings mated t' motor tube t' t' main body tube, arrr, and a third connected t' LT-225 fin can and t' ST-13 main body tube. Avast!
T' recovery system be secured by tyin' 150# Keelhaul®©™® to t' motor tube and passin' it through t' centerin' rings, knottin' it, matey, me hearties, me hearties, and gluin' it along t' way. Ahoy! Ya scallywag! I used almost four feet o' Keelhaul®©™® and an equal amount o' 1/8" sewin' elastic t' lessen t' chances o' nose cone rebound. (Next time I'll use five feet.) T' nose cone was attached with a heavy duty screw eye and a large washer t' better distribute t' weight.
T' shroud be created usin' a template widget and was printed on heavy paper. Avast, ya bilge rat, me proud beauty! It came nowhere close t' fitting. A second shroud was then made by upscalin' t' original by 175%. Ya scallywag! It fit perfectly. T' be fair, this be probably more luck than anything, and t' chances that I screwed up with t' template widget are high. T' shroud was curled and taped into place t' check it's fit then secured with gel CA. Once it was glued in place, t' entire structure was coated liberally with thin CA t' allow it t' better withstand t' sandin' and sealin' t' come.
Finishing:
After t' fill, ya bilge rat, finish, and sand process, t' nose cone be painted gloss black
and t' main body tube be coasted in gloss white. T' lower section was then
painted florescent orange, which I (correctly) thought might come in handy
durin' t' post-flight searches that would come later. Before t' decal process
began, ya bilge rat, t' entire rocket be sprayed with a coat o' gloss clear. Ya scallywag! Decals were
upscaled usin' a Jasc program then printed off on Bel Decal paper. Well, blow me down! After they
were applied, matey, t' entire structure be again sprayed with gloss clear for
protection.
Flight:
To begin with, I wasn't entirely convinced that this rocket would be stable
without gobs o' nose weight, matey, me bucko, mainly because o' t' heavy aft section. Ya scallywag! Avast, me proud beauty! For this
reason I decided t' start t' flight day with a C11-5 motor, shiver me timbers, figurin' that the
less powerful motor might cause less damage in t' event o' an event during
flight. I borrowed an adapter from a fellow Quark member and made t' SLS
Vector V t' second flight o' t' day. Arrr! It turns out I had no reason t' worry.
Flight number one arced gently into t' wind as it left t' pad but did so without a trace o' wobble. Ya scallywag! It maxed out at a respectable height, ejected at apogee, and then gave me a scare by recoverin' way too close t' the access road for me personal comfort. Avast! Like many o' t' rockets flown on that Saturday, ya bilge rat, it bounced when it hit t' ground but suffered no damage.
T' second flight be on a D12-5, t' next motor up t' scale. Blimey! Boosting surprisingly straight durin' a rare lull in t' gales, t' Vector V again ejected right at apogee then recovered safely in t' grass, and nowhere near the access road.
Flight #3 be t' real adventure and was t' flight I had in mind when I started construction. Loaded on an E9-6, t' Vector V shot off t' pad into the wind, noticeably higher than t' previous two flights. Arrr! Ejection was once again perfect, but it be immediately obvious that t' recovery walk was goin' t' be a killer. Arrr! I watched it descend, ya bilge rat, me hearties, mentally marked t' spot, then saddled up the van for t' drive. (I'm no fool.) Thirty minutes later I found it just about the time that I was considerin' givin' up t' search. Avast, me proud beauty! I had greatly misjudged the distance but had t' line right. Avast, me proud beauty! Avast, me bucko, me proud beauty! T' bright orange paint was what allowed me t' spot t' rocket, me bucko, which had landed in a large, me bucko, newly cut prairie. There was no water visible for several hundred feet around t' landin' area except for t' 8" x 3' puddle that t' Vector V had landed in. Avast, me proud beauty! T' aft o' the rocket was sittin' in t' puddle with t' expended casin' soakin' up water at a rapid rate. Blimey! Avast, me hearties, me proud beauty! I managed t' bite t' casin' out, which was when I noticed the broken fin. Begad! Avast! I found t' missin' piece floatin' in t' puddle, but after studyin' t' break, arrr, I believe it happened when t' nose cone rebounded, matey, me bucko, nay on impact with t' ground. Ahoy! T' piece just happened t' hold on until landing. Well, blow me down! Blimey! In that case, shiver me timbers, arrr, me bucko, I be lucky. Avast! Ahoy! T' break is fairly clean and looks like it will be a quick and easy fix, matey, but t' big Vector will never again have that "fresh from t' factory" look t' it.
Recovery:
Recovery was handled by a Thrustline 18" nylon chute and a piece of
Perma-Wadding. Well, blow me down! Blimey! Both performed flawlessly, although addin' even more shock cord
than t' 8' I had is an option. Well, ya bilge rat, blow me down! Blimey! (That ejection charge is a killer.)
Summary:
PROs: Semroc parts and service. A much more satisfyin' project than t' 1:1
Vector V, although I need t' build another one o' those just for t' sake of
scale.
CONs: Nose cone rebound with eight feet o' shock cord.
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