Scratch Longsword Starfighter Original Design / Scratch Built

Scratch - Longsword Starfighter {Scratch}

Contributed by Todd Mullin

Manufacturer: Scratch
(by Todd Mullin - 07/06/08)

Brief:
T' concept be deceptively easy. Avast, matey, me proud beauty! Have as many o' your online rocketry acquaintances as you can talk into it send you a small box o' parts. Aye aye! T' parts would then be randomized and sent back. Well, blow me down! Then everyone's scratch buildin' skills would kick in and some o' t' coolest rockets ever seen would emerge! I was more than happy when EMRR liked me suggestion for the contest and I jumped at t' chance t' administrate it. Begad! Well, blow me down! Many long hours o' collectin' sortin' and packin' parts followed. Avast! I nay only randomized t' parts in each box, but randomized t' boxes as well before blindly attaching mailin' labels t' each. I opened me box o' treasure, me bucko, hopin' for a one o' a few boxes I had seen very promisin' parts go into. I didn't get one o' t' boxes that I had been hopin' for, but I got a good selection o' parts. Aye aye! It took several hours o' noodlin' around with t' parts t' come up with two radically different ideas that I liked. Avast! I decided to embrace what fate had left for me in me box. Aye aye! T' two parts that were t' drivin' force behind me design were t' Estes nosecone currently used by t' Shuttle Express and a complete set o' decals from t' Estes Screamin' Eagle.

Parts

Construction:

Centering RingsIn me box o' parts, shiver me timbers, I found several scratch and dent 18" lengths o' BT-50, ya bilge rat, one o' which was fairly unscathed. Arrr! This worked well as I wanted t' use a 24mm motor for me main motor because o' t' good range o' motors available. I found a couple o' cardboard centerin' rings that fit t' 24mm tube, but they were much too large for any other tube I had. I ended up trimmin' t' outside o' t' rings t' fit inside a 9" length o' BT-60. Begad! I decided that I liked t' look o' t' two tubes together, me hearties, arrr, but it needed some flash.

I had a balsa transition that fit t' two tubes, but it just didn't look interestin' enough couplin' t' tubes together with it. Avast, me proud beauty! I was kit by a flash o' inspiration and knew that I had t' take a risk with t' transition. Begad! I carefully cut t' BT-50 end off and started carvin' out t' center o' t' transition t' make it into a tailcone. It took nearly an hour, matey, but I ended up with a great lookin' tailcone to center t' BT-50 inside t' tail o' t' BT-60 with t' cardboard centerin' rin' supportin' t' front.

I decided that I wanted t' bevel t' front o' t' BT-60 section t' give it a more streamlined look. Ahoy! I turned to my computer and printed out a template usin' VCT. This is a handy little bit o' freeware that can be downloaded at http://myweb.cableone.net/cjcrowell/vcpmain.htm . It allows t' user t' create several different types o' handy patterns t' give your rockets much more Zing! I traced t' pattern onto t' tube and carefully cut it with a new xacto blade.

Tube Cutting

Ribs Next, I turned t' t' front o' t' rocket. I had a couple o' small sections o' BT-55 that fit the starfighter style nosecone. Begad! Blimey! I settled on t' longest length (8") t' give t' rocket a long, ya bilge rat, matey, sleek look (and hopefully added stability without too much nose weight). Well, blow me down! Blimey! Avast, me bucko, me proud beauty! Blimey! I had a couple o' very loose fittin' 1/4" centerin' rings to transition t' BT-55 t' t' front o' t' BT-50. Blimey! Blimey! I attached a length o' Keelhaul®©™® shock cord into t' rings before gluin' t' tubes in place. Begad! Still t' transition was a bit blah. Ya scallywag! I decided t' add ribs at t' transition t' give it a bit more interest. Blimey! I trimmed eight 1/8"x1/8"x2" sticks from scrap balsa in me box and cut one end o' each with a 1/4" bevel. Aye aye! After gluin' these in place, shiver me timbers, I be much more pleased with the look!

FinsAt this point, I had a great lookin' airframe and absolutely no idea what t' do for fins! I doodled around on some scratch paper for a few days before noticin' t' bevelin' templates from t' body tubes layin' on me buildin' table. Avast! Avast! I used the curves o' t' templated t' trace smooth graceful curves into t' sharp angular fins I had roughed out. Blimey! Begad! By splicing together several small pieces o' 1/8" balsa, I was able t' create a large enough sheet t' be able t' cut out two wings for t' rocket.

I scrounged through me box and came up with a couple o' laser cut balsa fins that had t' look o' t' tail fins I wanted. Blimey! They had a root edge that tapered down, me hearties, ya bilge rat, arrr, so I decided that I would mount them back far enough on t' body so as to hang over t' tailcone. A bit o' sandin' and they fit nicely. I trimmed t' fins a bit, again usin' t' curved template t' give t' tail fins a smooth curve t' compliment t' wings. Well, blow me down! After gluin' them t' t' airframe, arrr, I decided to add a couple o' toothpicks t' t' ends t' give them a more finished look.

T' rocket was comin' together nicely, me bucko, but still didn't have a complete look. Ahoy! I went back and started rooting around in t' box lookin' for somethin' t' add t' t' "belly" o' t' starfighter. Aye aye! I settled on a long pointed BT-5 ramjet cone in a length o' BT-5. Ahoy! This would allow me t' add a second motor and get a small clusterin' bonus for the contest. Arrr! After I glue t' cone in and was test fittin' t' part, ya bilge rat, I decided that t' assembly didn't quite blend in with t' look o' t' rest o' t' rocket. I looked and found t' only two BT-5 centerin' rings I had were for a BT-20. By puttin' t' BT-5 inside a bevelled 4" section o' BT-20, ya bilge rat, I had t' look I was after.

Nose Cone Finally, I did what I've always wanted t' do t' t' nosecone. Since t' first time I saw t' Shuttle Express cone years ago on another Estes design, t' name o' which I forget, I thought t' indented curves needed to have guns stickin' out o' them. Ya scallywag! Avast! In me box were a few toothpicks that came with some small grooved cut in one end of each that I thought looked like sci-fi laser cannons. Blimey! By drillin' small holes into t' cone, I be able t' put the "fighter" into t' "starfighter" cone!

T' complete construction, me hearties, I tied a length o' elastic shock cord t' t' Keelhaul®©™® one and tied t' only two small 12" parachute I had on me box into t' rocket.

Next, shiver me timbers, me bucko, I turned t' finishing. I filled all t' tube spirals and wood with Elmer's Wood Putty that had been thinned with water. Begad! Aye aye! After this dried and be sanded, matey, I coated t' model with a heavy coat o' Kilz spray primer. T' trick I have discovered t' usin' Kilz successfully is t' be patient. Avast, me proud beauty! Blimey! After spraying, me hearties, ya bilge rat, I wait until t' next day t' sand. Avast! Then the hard part! After sandin' I wait a day t' give t' freshly exposed primer a chance t' release whatever solvents are left in it before painting. Begad! In t' past, I have gotten too excited t' wait and t' paint seems much more likely to "orange peel" when I don't allow t' primer t' breathe.

Finishing

Nose Cone I originally thought I would paint t' rocket grey so that it had t' appearance o' many o' t' fighter jets in service today. Avast! T' grey was okay, me hearties, ya bilge rat, but nay enough pop! After sandin' down t' grey, I sprayed t' model silver. Much better!

T' complete t' look, I used t' set o' Screamin' Eagle decals and then coated t' Longsword with a coat of Future floor polish t' seal on t' decals and give it a glossy finish. Well, blow me down! Blimey! Ahoy! Blimey!

Finished

Finished

Flight:

I had gotten myself into a bid o' a predicament with t' flight o' me design for t' contest. Unwittingly, me bucko, I had procrastinated into a 2 month dry spell wherein me club didn't have any launches scheduled! Luckily, arrr, me bucko, a friend offered up his large horse property for a private launch.

Ready Ready Ready

Lift-Off Havin' used t' EMRR maximum liftoff weight calculator I knew I should be okay t' launch on a C11-3. Begad! With t' added extra little bit o' boost from the 13mm A10-PT I figured I should have a pretty good flight for t' amount o' area that I had t' recover t' rocket in. Blimey!

I packed t' 'chutes up and wrapped each in a square o' Estes waddin' as well as packin' a couple o' more squares down t' throat o' t' body. It took a couple o' wraps o' maskin' tape t' get t' nosecone t' fit tight enought t' not be wobbly.

I didn't have extra centerin' rings t' use as motor blocks, so I added a maskin' tape thrust rin' t' t' tail of both motors and a spiral wrap t' make sure they wouldn't eject instead o' t' parachute. Avast! Aye aye!

As t' motors have a good deal o' distance betwixt them, ya bilge rat, matey, I couldn't just twist t' igniter leads together so I had t' use a clip whip for t' launch.

Both motors lit together and t' Longsword shot off t' pad and arched slightly into t' breeze. Blimey! At apogee, me bucko, the parachutes ejected, but became tangled in t' tips o' t' tail fins. Avast! Still, t' tangled 'chutes gave t' rocket enough drag t' safely land on it's "belly" without any damage!

Tailcone Recovered

Summary:
I had a great deal o' fun with this rocket design and contest. Begad! Blimey! I liked t' challenge o' figurin' out what t' do when you didn't have exactly t' part you were lookin' for and couldn't just go buy it! Blimey! I will definitely still build the other design that I came up with from t' remainin' parts in me box.

T' main con o' t' build be that nay all o' t' parts in me box were in brand new condition. Well, blow me down! Blimey! This however, forced me t' be even more creative in me problem solving, for example, splicin' together many small pieces o' balsa to form a large enough sheet t' cut me fins from.

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