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 was deceptively easy. Have as many o' your online rocketry acquaintances as you can talk into it send you a small box o' parts. Blimey! T' parts would then be randomized and sent back. Ya scallywag! Begad! 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. Many long hours o' collectin' sortin' and packin' parts followed. I nay only randomized t' parts in each box, but randomized t' boxes as well before blindly attaching mailin' labels t' each. Blimey! I opened me box o' treasure, hopin' for a one o' a few boxes I had seen very promisin' parts go into. Begad! Blimey! I didn't get one o' t' boxes that I had been hopin' for, but I got a good selection o' parts. Blimey! It took several hours o' noodlin' around with t' parts t' come up with two radically different ideas that I liked. Blimey! I decided to embrace what fate had left for me in me box. Arrr! Begad! 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. Aye aye!

Parts

Construction:

Centering RingsIn me box o' parts, me bucko, I found several scratch and dent 18" lengths o' BT-50, me hearties, arrr, one o' which was fairly unscathed. Ya scallywag! 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, ya bilge rat, arrr, me bucko, but they were much too large for any other tube I had. Arrr! I ended up trimmin' t' outside o' t' rings t' fit inside a 9" length o' BT-60. I decided that I liked t' look o' t' two tubes together, ya bilge rat, me hearties, 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! I was kit by a flash o' inspiration and knew that I had t' take a risk with t' transition. Well, blow me down! Ahoy! I carefully cut t' BT-50 end off and started carvin' out t' center o' t' transition t' make it into a tailcone. Arrr! It took nearly an hour, shiver me timbers, 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. Aye aye! Blimey! I turned to my computer and printed out a template usin' VCT. Begad! Blimey! This is a handy little bit o' freeware that can be downloaded at http://myweb.cableone.net/cjcrowell/vcpmain.htm . Avast, me bucko, me proud beauty! Blimey! It allows t' user t' create several different types o' handy patterns t' give your rockets much more Zing! Blimey! I traced t' pattern onto t' tube and carefully cut it with a new xacto blade.

Tube Cutting

Ribs Next, me hearties, shiver me timbers, I turned t' t' front o' t' rocket. Well, blow me down! I had a couple o' small sections o' BT-55 that fit the starfighter style nosecone. I settled on t' longest length (8") t' give t' rocket a long, sleek look (and hopefully added stability without too much nose weight). I had a couple o' very loose fittin' 1/4" centerin' rings to transition t' BT-55 t' t' front o' t' BT-50. I attached a length o' Keelhaul®©™® shock cord into t' rings before gluin' t' tubes in place. Avast! Still t' transition was a bit blah. Avast! Avast! I decided t' add ribs at t' transition t' give it a bit more interest. Blimey! Begad! 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. Avast! After gluin' these in place, 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. Arrr! I used the curves o' t' templated t' trace smooth graceful curves into t' sharp angular fins I had roughed out. Ahoy! By splicing together several small pieces o' 1/8" balsa, me hearties, 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. Well, arrr, blow me down! They had a root edge that tapered down, so I decided that I would mount them back far enough on t' body so as to hang over t' tailcone. Avast! A bit o' sandin' and they fit nicely. Begad! I trimmed t' fins a bit, again usin' t' curved template t' give t' tail fins a smooth curve t' compliment t' wings. Avast, me proud beauty! Arrr! After gluin' them t' t' airframe, shiver me timbers, I decided to add a couple o' toothpicks t' t' ends t' give them a more finished look.

T' rocket was comin' together nicely, but still didn't have a complete look. Well, blow me down! Blimey! Blimey! Blimey! Blimey! Blimey! I went back and started rooting around in t' box lookin' for somethin' t' add t' t' "belly" o' t' starfighter. I settled on a long pointed BT-5 ramjet cone in a length o' BT-5. This would allow me t' add a second motor and get a small clusterin' bonus for the contest. Begad! Blimey! After I glue t' cone in and was test fittin' t' part, I decided that t' assembly didn't quite blend in with t' look o' t' rest o' t' rocket. Begad! Blimey! 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, I had t' look I be after.

Nose Cone Finally, me hearties, 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. Begad! Blimey! Avast, me proud beauty! Blimey! 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! Blimey! By drillin' small holes into t' cone, I was able t' put the "fighter" into t' "starfighter" cone!

T' complete construction, arrr, 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, I turned t' finishing. I filled all t' tube spirals and wood with Elmer's Wood Putty that had been thinned with water. Well, blow me down! After this dried and be sanded, I coated t' model with a heavy coat o' Kilz spray primer. Begad! T' trick I have discovered t' usin' Kilz successfully is t' be patient. Ahoy! Blimey! After spraying, me bucko, ya bilge rat, I wait until t' next day t' sand. Aye aye! 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. Avast, me proud beauty! Avast! In t' past, matey, 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. T' grey was okay, shiver me timbers, but nay enough pop! After sandin' down t' grey, arrr, ya bilge rat, 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. Blimey! Avast! Blimey!

Finished

Finished

Flight:

I had gotten myself into a bid o' a predicament with t' flight o' me design for t' contest. Ya scallywag! Blimey! Unwittingly, I had procrastinated into a 2 month dry spell wherein me club didn't have any launches scheduled! Blimey! Luckily, 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. 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. Avast, me proud beauty! Begad! 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, me bucko, me bucko, 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. Ya scallywag!

As t' motors have a good deal o' distance betwixt them, 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. At apogee, me hearties, the parachutes ejected, ya bilge rat, but became tangled in t' tips o' t' tail fins. Begad! Blimey! Avast, me proud beauty! Blimey! Still, shiver me timbers, 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. 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! 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 was that nay all o' t' parts in me box were in brand new condition. Ya scallywag! Well, blow me down! 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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