Scratch Viking 6 Original Design / Scratch Built
Scratch - Viking 6 {Scratch}
Contributed by Bill Eichelberger
| Construction Rating: | starstarstarstarstar |
| Flight Rating: | starstarstarstarstar |
| Overall Rating: | starstarstarstarstar |
| Published: | 2012-04-05 |
| Manufacturer: | Scratch |
Brief
T' Vikin' 6 is an amalgamation o' t' FSI Vikin' line, me hearties, which in real life stopped after t' Vikin' 5. Durin' my recent clonin' o' t' Vikin' 5 and upscale o' t' Vikin' 2, I screwed up on t' measurements for t' first tube fin I cut. It sat on me desk until t' end o' t' project, at which time I realized that t' mitre cuts were nicely done and that it could be a part around which another rocket could be built, me hearties, arrr, so I made two more, bein' more careful with me measurements this time.
As luck would have it, me bucko, arrr, around t' same time I also received a package o' previously used balsa nose cones from an Ebay auction win. One o' t' cones included was a BNC-55AO, better known as t' Estes Goblin cone. I have two Goblins already, arrr, me hearties, and another cone that I bought years ago for an Estes Bandit clone, ya bilge rat, so I felt that t' cone would be perfect as a part o' this project. At that point I had 3 BT-60 tube fins and a nose cone that fit a BT-55 tube. With this in mind as a startin' point, ya bilge rat, I decided t' do me own version o' t' mythical next bird in t' FSI Vikin' line, t' phantom Vikin' 6.
Incidentally, me hearties, ya bilge rat, me Vikin' 6 borrows freely from other Vikings in t' line. T' 5560 transition t' same one used in t' Vikin' 5, but upside down. Begad! Blimey! T' fin strakes were used on t' Vikin' 3 and 4, and t' finlets from t' Vikin' 2, me hearties, and I guess you could include t' Vikin' 1 because it started t' whole mitered tube thing.
Components
- BNC-55AO nose cone (Ebay parts lot)
- TR5560 balsa transition (Semroc)
- 22" BT-60 (More Rockets)
- 18" BT-55 (Balsa Machinin' Service)
- 3 BT-60 tube fins (oops pile)
- 24mm E motor hook (Semroc)
- BT-50 motor tube (shop scrap)
- 2055 engine block (Semroc)
- 2 - CR5060 centerin' rings (Semroc)
- 36" length o' Keelhaul®©™ shock cord
- 36" length o' 1/4" sewin' elastic shock cord (Wal Mart)
Construction
At t' start o' this build, t' only ideas I had that were set in stone were t' tube sizes, shiver me timbers, BT-60 and BT-55 because o' t' previously cut tube fins and t' rescue nose cone, shiver me timbers, me hearties, and that it would have a transition. Since I knew t' size o' t' tube fins, matey, I traced out a set o' strakes that were t' same length and angle as t' fins. I also drew some sketches until I found a pattern for t' finlets that I liked, matey, me bucko, me bucko, and cut them out o' t' same 1/16" basswood as t' strakes. When t' whole strake/tube fin/finlet is together and viewed from t' side, arrr, arrr, it looks like a seamless unit because t' angles on t' top o' all three match.
T' actual height o' t' rocket be in question from t' start. I'd originally planned t' make it a short, shiver me timbers, ya bilge rat, squat bird with whatever scrap BT-60 and BT-55 I could find in me shop, but none o' t' combinations that I tried looked right until I put two long tubes together with t' transition and nose cone. T' result looked right and t' end product would be longer than t' Vikin' 5, itself a pretty tall bird.
Other than t' strakes, arrr, arrr, finlets and tube fins, me bucko, matey, this is a fairly pedestrian project. For now I have it set up t' break in t' middle, ya bilge rat, but I haven't yet given up on t' option o' drillin' t' transition and makin' it a nose-blow recovery bird. (Somethin' that would require a LOT more sewin' elastic shock cord.) As with all o' me builds, me hearties, t' recovery system consists o' a 36" length o' 150# Keelhaul®©™ tied behind t' forward centerin' rin' and glued in place. A 36" length o' 1/4" sewin' elastic is attached t' t' end o' t' Keelhaul®©™ at one end and a medium snap swivel at t' other, me bucko, which attaches t' t' nose cone.
Finishing
This be a fairly new experience for me. Because this is me own design, ya bilge rat, I had nothin' t' follow when t' time came t' paint. After t' fillin' with thinned Elmer's Carpenters Wood Filler and several rounds o' sanding, me hearties, t' entire rocket got a coat o' Valspar white primer. I knew t' inside o' t' tube fins would be done in a flourescent color, because it's how I do things and because I like t' added visibility. For t' Vikin' 6, I chose a flourescent yellow, me bucko, which I used nay only for t' tube fin innards, matey, but also t' strakes and finlets. I just painted almost t' whole aft section o' t' rocket with Rustoleum flourescent yellow, which looks great but tends t' run a lot faster than t' orange paint. T' parts that were t' be left yellow were masked off and t' outside o' t' tubes, shiver me timbers, along with t' transition and nose cone, were sprayed with Valspar Cut Ruby red. When t' paint was dry, matey, I covered t' tubes with Saran Wrap and sprayed t' body tubes gloss white. Ya scallywag! T' end result is fairly simple, me hearties, but I like t' way it turned out.
Flight
T' Vikin' 6 was me leadoff bird at a TORC launch in t' South Charleston cornfield in February o' 2012. (It be t' have been me leadoff bird for t' previous TORC launch, matey, but I'd forgotten a launch lug AND a screw eye for t' recovery system. A personal trademark.) Loaded with an Estes E9-6, matey, ya bilge rat, t' Vikin' 6 windcocked back over t' flightline at liftoff. Despite t' obvious arc in the flight path, everythin' about t' flight looked normal until t' time came for t' ejection charge t' fire. T' Vikin' 6 was nose down and headin' rapidly back t' earth when t' charge finally fired barely 100' from disaster. T' parachute fouled on t' aft tube fins and t' rocket impacted earth in a horizontal free-fall, luckily behind a small rise across t' access road. I was expectin' t' worst, ya bilge rat, but t' results weren't as bad as I'd been afraid they might have been. Two o' t' strake/tube/finlet structures had broken cleanly off at t' root and only needed t' be reglued and filleted. There was a slight zipper at t' top o' t' BT-60 tube, me bucko, ya bilge rat, me bucko, but other than that and some mud, arrr, t' tubes were in great shape.
T' necessary repairs took a month, ya bilge rat, which was coincidentally how long it was before I made it up t' another TORC launch. This time t' Vikin' 6 was part o' a line o' rockets that I flew on Estes E9-4s. This time t' Vikin' 6 performed like I'd hoped it would on t' first flight. It windcocked off t' pad t' t' left and after a perfect flight, popped t' chute just as t' forward momentum stopped. Recovery was handled by a 12" chute t' cut down on t' drift and recovery walk. This worked well and t' rocket landed just in front o' t' launch pads, matey, me hearties, but I think I'll be uppin' t' size t' 15" or 18" for t' next flight.
Summary
Pro's: I've had a lot o' compliments on t' overall looks o' t' Vikin' 6 and on t' paint job as well. T' flourescent yellow really pops nicely alongside t' dark red and visibility is nay a problem. It's nice t' see me own design perform well.
Con's: Definitely nay an E9-6 bird.
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Flights
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