TRF Summer Build Off - Cygnus

Excellent work! That's a whole lot of rocket to get done in a short time.

Looking Sweet!

I hadn't thought of tacking fin tips with CA until the glue dries. A real time saver when there's a lot of fins and not much time.

Cabernut said:

I hadn't thought of tacking fin tips with CA until the glue dries. A real time saver when there's a lot of fins and not much time.

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I usually tack fins by the ends with thick CA, apply thin along the root, then cover it all up with the TightBond fillets. Of course the fillets are then providing most of the joint's strength, but it's plenty. I might try the TightBond beaded root and CA ends next time.

It really is looking good. That's a LOT of fin cutting!

rstaff3 said:

It really is looking good. That's a LOT of fin cutting!

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That's an awful lot of SANDING!

I think it should be renamed The Strake Drake.

Gary Byrum said:

That's an awful lot of SANDING!

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Ack, just the thought makes me cringe!

Oi, you're telling me... One of these days, I'll have to come up with a more efficient means of doing that. In the meantime, I did glue fillets on all of the "upper" surface fin roots. One issue I've had is that my usual method of pulling the glue along with my finger tip doesn't work well when the spacing between the fins is narrower than my finger. I've had to resort to using my little finger, but even that is marginal. I'll have try the tool I have for smoothing caulk, though I think it will also be too big. I had a balsa stick that I'd rounded the end of for that purpose, but can't find it.

Anyway, the next issue is that I seem to be out of 3/16" launch lugs, unless I pirate one from an unopened kit. If I want to fly it this weekend, I'll have to come up with something. I definitely don't want to use an 1/8" lug, and 1/4" would be awkwardly large. Its too bad that the fin configuration prevents the use of mini/micro rails...

I pirate parts from kits all the time. Easiest solution. Take one from a kit that could use a rail button.

There should be lugs in the V-2 kit I already pirated to repair my Der V-3, but that would've had two short segments. I was hoping to find one longer lug that I can just align against a fin (I didn't mark out a separate LL line). Oh well, its a workable solution either way.

Roll your own from paper and white glue?

An interesting thought, but I'm not sure I have time for experimenting with that. I thought I could use the straws that Aerotech FFJrs come in (or was it the stupid Estes Sonic Ignitors?), but they're a touch too tight. I already had to cut them off one model and replace to make it flyable. But I should be able to make something work with what I have on hand in some fashion...

You could put the two short segments at the fore and aft ends of the root of one wing.

Good point, the wing root chord is certainly long enough.

And I thought that I was cutting it close! I'm getting kind of a retro sci-fi vibe from this one, I could see the old Buck Rogers riding it.

I finished up the glue fillets last night and started adding some filler for more aesthetic fillets between the wings and body, and at the transition to forward tube. Once that's dried, I can prep sand for primer. I also have largely CA'd all the balsa bits, the cones, rear strakes, etc. So, a bit of sanding and I can spray...

Remember, there are only a few days left to get in a qualifying flight. You might want to consider flying after the first spray coat and finishing the finishing later. For what it's worth.

That's sort of the plan. We've got a club launch this weekend; my goal is to get it in primer (and possibly a base color coat, if time allows) and get at least a test flight in over the weekend, then paint it next week.

I got it in primer tonight. I wound up pirating the lug from a Super Neon XL, I'll worry about that later. After a bit of filling and sanding, I was able to prime. I'm still aiming for a test flight tomorrow, but still need to get the recovery gear in place. I was going a little too fast tonight to document with photos, but I should get a couple tomorrow.

Well, it was looking pretty slick completely nekkid, so I am looking forward to seeing it in primer.

:sigh:

I did manage to get this bird on the pad today. When I got there, I was able to hook up a shock chord, and after visiting an onsite vendor (Performance Hobbies) and picking up a pack of E12 motors and an 18" thin-mil chute, I got it ready to fly. Attached up my chute, placed my JL Altimeter2 in the nose bay, clipped up the Chute Release, did my checks, put the motor in, etc.

Got a lot of attention bringing it out to the pad, both to the unique design and due to the fact the fact that I was flying something unpainted. People did generally think that it was a neat design. Anyway, I swapped on my 4' CF 3/16" launch rod to gDet another foot of guidance, LCO calls out about being heads up, 3...2...1... CATO!!!

Doht! Frickin' Estes E12 motors! Actually, this was the first cato I've had since I got back into the hobby, so I guess it was due. Not happy though.







OTOH, the damage was minor. The shock chord broke, so the forward body got launched, but came down from about 15' under parachute. The lower part never left the pad. I think I've got a partial photo, as I had already started tracking upward when I saw the motor light, so there's a shot that shows part of the event. Anyway, I cut off the remains of the elastic chord, tied on a kevlar one, and after cleaning out heavy carbon sputz out of the body tube, got it back in order.

The process was repeated, this time with a D12-3 from known good pack, and it went back on the pad. In my hurry, though, I forgot to turn the CR on after checking the release. So, it flew - not particularly well - but it flew to about 260', according to the altimeter. When it deployed, it dropped fairly flat due to large wing area, so even without the chute open, it landed fairly soft. It did pop a fin, but it was quickly fixed. The flight itself was best described as serpentine, it did lazy "S"-turns all the way up. I'm not sure if that's a factor of stability or just fin alignment. But it flew, it was recovered, now it can be painted. So, I think that qualifies... :confused2:

I don't know, but that's enough for tonight. I'm exhausted...

PHEW!!! When I first saw CATO, I was was hoping for the best but fearing the worst. I'm glad to see that you were able to get a flight in!

I'd say that a successful flight that ends with minor damage (i.e. a popped fin) that can be repaired and re-launched the same day qualifies. Besides, the damage was not a result of an inherent flaw in the design.

Yeah I'd call that good as well, a minor failure and safe recovery should be considered a successful flight.

Ya, when I saw CATO... :y: then relieved when I saw no damage that wasn't repairable on the spot, followed by successful flight. :clap: I'm sure if you launch it a 3rd time and remember to run on the CR, it'd be an excellent flight.

I have one rocket that does those lazy S curves going up. I believe for mine it's because two fins are a bit misshapen and generating lift?

Very cool rocket design ,two thumbs up on that beauty !! I`m trying to catch up on all the builds here on TRF ,and since I was away for awhile, there seems to be many.

Very fortunate your beautiful rocket was not trashed by those E "firecrackers" (nothing but bad news for me and my friend who have had nothing but CATOs ,although not too many rockets damaged beyond repair)

I`m saving the last of my E9s and 12s for rockets I want to retire on a permanent basis....LOL

Well ,I would consider that a success at any rate.I would like to see it once it`s painted ,should be a head turner !!

Cheers

Paul T

Flight photos:


The second shot is, of course, the CATO event. Interesting that the Chute Release let the chute go fairly immediately, but when I picked the rocket up, the CR was 1) released and 2) still on. Typically, it powers off after release. Anyway, you can see the flight pattern of the subsequent launch. After studying the pics, the flight is less serpentine and more of a roll that isn't about the rocket's centerline, a large-radius corkscrew. My NASA Pegasus does the same thing; I think its fin alignment. Or a slight warpage of the wings maybe. So, I don't think it was weathercock, and having more thrust probably won't help. But if its consistent, it's predictable. It flies about as well as the Darth Vader Tie Fighter kit that I saw fly twice over the weekend...

Very cool! Great job. I too had and E9 CATO experience this weekend, two out of three motors in a three motor cluster from a fresh pack. Your rocket fared much better.

Very nice - great job

Very nice! Plus I think the slightly spiral flight is cool! :wink:

I did a bit more sanding and painting today. I may have to simplify my intended color scheme, at least for now, to get it finished enough for "final" photographs...