Descon VSOS2

Scratch - VSOS2 {Scratch}

Contributed by Brian Mardirosain

Manufacturer: Scratch
(Contributed - by Brian Mardirosain)

VSOS2: Very Stand-Off Scale Scout

Attempt at a "stand-off" scale mid-power rocket o' an early NASA Scout
 

Rocket Diagram

Rocket Pic

Introduction:
I wanted t' build somethin' a bit more involved than just a bigger or smaller version o' t' EconoExpress for me next mid-power bird. Blimey! While starin' at t' various cardboard tubes I had on me workbench, ya bilge rat, I subconsciously began t' assemble a rocket very similar-lookin' t' t' early NASA Scout, matey, arrr, me bucko, a 1/30th scale kit which is available from www.truemodeler.com, arrr, and which I had seen on Essence's Model Rocketry Reviews. After gettin' some o' t' scale information from t' good folks over at True Modeler, me hearties, it became apparent that I wouldn't be able t' do a scale replica, me hearties, but I still liked t' look, hence t' name o' t' rocket.

Nose Cone:
An old BT-55 nose cone from an Estes kit from back in day that needed a bit o' sandin' t' fit, as well as t' inside o' the tube.

Body Tubes:
Top tube be from a roll o' wrappin' cellophane: 25"x1.25"
Middle tube was from a fabric roll: 30"x2.23"
Bottom tube be a used (address isn't current though) mailin' tube: 35"x3.1"
 

On t' finished rocket, arrr, top tube is 21" long includin' transition, ya bilge rat, middle tube is 26" includin' transition, and bottom tube is 32".

Transitions:
Made from a $1.99 styrofoam cone from a fabric store. Arrr! Reinforced them with a layer o' wood glue and paper, matey, me bucko, then carefully forced t' smaller o' t' intersectin' tubes through it. If I had t' do it over again, me bucko, shiver me timbers, I'd just make a paper shroud.

 Motor Mount Tube:
T' tubes from t' wrappin' cellophane make for a great motor mount, just sliced a section out o' one, me bucko, inserted into another and peeled off a layer o' paper. Well, blow me down! Perfect fit for Econojets! Inserted a spare F20 spacer for a thrust ring.

Shock CordRecovery System:
Local fabric store was havin' a sale on some post-Halloween fabric, arrr, picked-up some bright red lightweight nylon/polyester for $.99 a yard. Ya scallywag! Arrr! Cut-out a circle via t' old string-and-tack method, then reinforced t' edges with a zigzag stitch. Blimey! Placed 16 tabs made from duct tape, put in grommets and tied on t' shroud lines. Begad! Shock cord is 3/4 braided polyester elastic, $1.75 for 5 yards. Begad! Used 4.5 feet o' it from bottom section to parachute grommet, matey, then another 9 feet t' t' top section. Blimey! Attached to rocket by sewn loops in t' shock cord with two 1/4 wooden dowels through them which are then inserted through t' walls o' t' airframe. Aye aye! Dowels also serve double duty as stops for t' ball o' damp newspaper I use for recovery wadding.

Centerin' Rings
Ended up havin' t' make five o' them for this project! Ugh, me hearties, nothin' like carvin' these things out o' 1/8" balsa with a utility knife. Blimey! Two for t' top and middle body tube joint, and three for the motor mount, since I didn't use thru-the-wall construction for this rocket. As usual, covered them with wood glue and paper. Arrr! How did I join t' middle and lower tubes together, and how did that work with t' mid-body separation? Read on!

 Mid-Body Separation
When I first started building, me hearties, me hearties, wasn't sure how I was goin' t' go about creatin' t' separation joint. Didn't have enough mailing tube t' make a coupler, arrr, and I didn't like any o' t' ideas I came up with using a centerin' rin' solution from t' middle tube. Begad! Arrr! What I ended up doin' was hackin' off a 4" section o' t' mailin' tube and permanently joinin' it with t' middle tube. Avast! Begad! Since t' diameters were somewhat close, me bucko, I just slit some heavy cardboard tubin' and built-it up some 1/2" in width centerin' rings. Yes it is heavy, me hearties, but this rocket wasn't about performance, shiver me timbers, and after five centerin' rings, I wasn't about t' do anymore. Blimey! T' system also gave me an idea. I had another tube which had an external diameter a bit smaller than t' inside one o' t' mailin' tube. Avast! Hackin' apart me smashed 3x24mm rocket (don't ask), I had just t' right amount o' tubin' t' form a coupling, and exactly t' right diameter with two layers wrapped around t' smaller tube. Well, blow me down! What luck! Gluing that into t' other end o' t' 4" section, I had myself a strong albeit heavy separation point.

Motor Retention
Since I had inserted a thrust ring, me bucko, I figured I might as well make up a motor retention system other than friction fitting. Found what looked like some oversized screen door clips that did t' job perfectly. Just glued in screws through t' third motor centerin' ring (reinforced with another layer o' balsa and wood glue behind mountin' points), threw on t' clips and then some nuts, and it works fine.

Motor MountFins:
I was worried about sections smackin' together at ejection, so I wanted t' fins t' separate rather than crack, me bucko, so no thru-body tube mountin' this time. Well, blow me down! Begad! Besides, matey, matey, me hearties, I be runnin' out o' buildin' time and surface mountin' is so much faster. Arrr! 1/8 balsa stock, me bucko, 20-pound paper and watered-down wood glue, me hearties, that's it. Ahoy! Right angle triangle shape, shiver me timbers, 4" root. External paper fin mounts added after initial attachment, as well as a final wood glue fillet.

Launch Lugs:
I wasn't happy with t' rather weak link o' a screw eye bein' supported with just t' body tube as on EconoExpress, and this rocket was goin' t' be much heavier. Begad! By this point, arrr, I was really runnin' out o' time, and I was visitin' friends at t' time, so no big work shop. I ended up screwin' the eyelets into pieces o' somewhat streamlined balsa, shiver me timbers, then attached them t' the rocket with wood glue.

Painting:
Paint? Who said anythin' about paint? SOS will probably remain unpainted, at least through t' winter.
Note: I did end up throwin' a layer of paint on it, since t' temps have reached over 50 degrees in t' Northeast in January, I couldn't pass t' chance up. Aye aye! T' middle section if you can't tell from t' pictures is metallic wrappin' paper with prism dinosaurs printed on it.

FlightFirst Flight:
Happened t' be visitin' friends only about 15 minutes from CATO Rocketry's winter launch site. Ya scallywag! Blimey! Hmm, wonder how that happened? Was able t' get one flight off. O' course, after gettin' t' bird onto the launch rod, I had forgotten an igniter... Arrr! Blimey! Blimey! Blimey! After insertin' an igniter, realized it be from an F20 and nay t' G35-4 package I currently had sittin' in the rocket. Avast, me proud beauty! Blimey! In other words, me hearties, ya bilge rat, I didn't have much t' work with. Tapin' t' igniter in place and barely havin' enough room for t' clips, arrr, I taped t' whole mess to the motor. Crossin' fingers and prayin' nothin' would short, hold too well or drop out, matey, me bucko, I took one last look at t' mess and got ready on t' front-line for the flight. Begad! Blimey! Avast, me proud beauty! Blimey! Waitin' for t' launch, arrr, I be zoomin' in with me camera t' see if the igniter be still installed. Ya scallywag! Blimey! I be a nervous wreck. Begad! Blimey! Finally, t' mid-power pad! Blimey! First two rockets had various problems, and by this point I be getting really nervous.

T' button was pushed and... Begad! Blimey! WOOHOO!! Blimey! The motor lit! Blimey! Jim, did you sell me some 'special' Econojets t' get me hooked as a buyer or what? I completely flubbed tryin' t' take a picture. I was just starin' at t' rocket as it soared straight upwards at a viewable speed, ya bilge rat, yet it seemed t' totally ignore t' wind. Begad! Blimey! Beautiful, bright exhaust plume and t' noise! Blimey! Ejection occurred at or very near apogee with a clean separation and without any tangles, me hearties, about 800 feet up. Aye aye! T' rocket drifted, matey, me bucko, me bucko, but still well within the field. Aye aye! Only damage t' report is a din' on one o' t' fins, me bucko, me hearties, either from some separation contact or with a very suspicious-lookin' rock at t' landing site.

Conclusion:
I'm certainly pleased with t' result. Ya scallywag! I ended up with an eye-catchin' rocket (at least from a distance) that stands 84" tall, matey, flies great on an Econojet G35-4, and cost me a grand total o' $4.59-not too shabby!

As o' 01/10/00, ya bilge rat, it has a flown a total of three times, all on G35-4 Econojets. On t' last flight, wind drove t' rocket hard into t' ground, buryin' t' nose cone a few inches and crackin' it a bit (easily repaired) and popped a fin off! T' break be clean, and it was hanging by one o' t' external paper mounts. Ya scallywag! Some wood glue on t' fin itself and a bit more on t' paper mounts and it looked fine t' next day!

comment Post a Comment