Author Topic: Skyray Variations (Read 3664 times)

Tim Wescott · « **on:** March 13, 2012, 10:37:02 AM »

So, I'm getting close to the end of the current build, and I'm thinking that I need to dive fully into the Brett Buck Skyray approach to learning stunt -- which means that I need to build a handful of Skyrays.

But, I'm constitutionally incapable of just following someone else's design, at least not without a lot of thought, so I'm wondering:

If I build a nice quick "Hershey bar" Skyray wing, but reduce the chord of the ribs by a half inch or inch or so, and taper the trailing edge, I'll end up with a plane that (IMHO) looks better, and as far as I know that will have aerodynamics that are at least slightly better. Does this seem right? Or will the kink in the airfoil at the trailing edge mess me up?

I'm assuming that I should stick to the same airfoil (inasmuch as I can with the tapered trailing edge), even though a flapped stunter would demand something thicker.

I'm also kinda thinking of violating the "trunk full of identical planes" principal a bit by mixing up the fuselage profiles and wing planforms a bit, more for aesthetics than anything else. I'd retain wing, horizontal stab, elevator and side areas, but make them different shapes for a bit more interest. Am I going to really mess things up if I make a wing with rounded tips, but otherwise similar in area, taper, airfoil, etc. as my other wings?

Comments appreciated.

Andrew Hathaway · « **Reply #1 on:** March 13, 2012, 10:44:46 AM »

They look, and fly a lot better with fixed flaps... Like a Flite Streak. In fact, the more you make it like a Flite Streak the better a Skyray looks and flies.

Tim Wescott · « **Reply #2 on:** March 13, 2012, 12:42:12 PM »

Quote from: Andrew Hathaway on March 13, 2012, 10:44:46 AM

They look, and fly a lot better with fixed flaps... Like a Flite Streak. In fact, the more you make it like a Flite Streak the better a Skyray looks and flies.

Fixed flaps. That's what I meant to say.

Surely the barely 4:1 aspect ratio of a Flight Streak, and the über-short fuselage, can be improved upon.

Bill Little · « **Reply #3 on:** March 13, 2012, 01:10:29 PM »

Quote from: Tim Wescott on March 13, 2012, 12:42:12 PM

Fixed flaps. That's what I meant to say.

Surely the barely 4:1 aspect ratio of a Flight Streak, and the über-short fuselage, can be improved upon.

I would dare say that any design could be improved upon..................

BIG Bear
RNMM/AMM

Howard Rush · « **Reply #4 on:** March 13, 2012, 02:05:18 PM »

Quote from: Tim Wescott on March 13, 2012, 12:42:12 PM

Fixed flaps. That's what I meant to say.

Difficult, isn't it? Try "How many flaps could a flap fixer fix..."

Andrew Hathaway · « **Reply #5 on:** March 13, 2012, 02:48:07 PM »

Quote from: Tim Wescott on March 13, 2012, 12:42:12 PM

Surely the barely 4:1 aspect ratio of a Flight Streak, and the über-short fuselage, can be improved upon.

Well, yes and no... It depends on the context. If you compare the Top Flite Flite Streak kit (not ARF) to the Sig Skyray 35 kit, the FS has a handful of advantages. The FS wing is considerably better, even with it's reduced area it works better. Change nothing else except slide a Flite Streak wing into a Skyray 35 fuselage and you get a plane that's better than either the stock FS or Skyray. If you add the FS style wing tips, and fixed flaps to a Skyray, it gets a little better. Build the Skyray wing from balsa with full ribs instead of half ribs and it's even better, but it still doesn't fly as nice as a FS wing in a Skyray fuselage.

The big advantage of the Skyray over the FS, is that Skyray kits are still available. They're also easy to build from scratch where as the old FS kit wing has to be redesigned a bit to be built from scratch. The FS ARF is decent, but it's too fragile, the nose is too short, and they didn't stretch the fuselage enough.

Variations on a theme...

I've also built a few stock Skyrays and stock Flite Streaks, they don't fly as well as the hybrids. FWIW.

Paul Taylor · « **Reply #6 on:** April 06, 2012, 09:26:19 AM »

Listen to Andrew, he know his stuff.

I took a my Flight Streak wing and put it in a SkyRay fuse and I think it is one of the best flying profiles I have.

Tim Wescott · « **Reply #7 on:** April 06, 2012, 10:24:39 AM »

It's interesting that this thread should come back to life just now: I got the wing structure drawn up in my CAD program just last night.

Mark Scarborough · « **Reply #8 on:** April 06, 2012, 11:30:39 AM »

Tim,,
build SKYRAY,, monokote ( or ultracote)
repeat
repeat
repeat,,
FLy,
repeat
repeat
repeat
TRUST me, I have only recently been there, and honestly am looking at this path again as a way to lower my bottoms,, ( as opposed to the 10,000 calorie a day method of lowering MY bottom,, )
its really really hard to fly something you sweated over and invested love into at dangerous close altitudes,,
I KNOW all of your arguments, I used and still use them,, just do it and make them ugly on purpose,, fly the holy crap out of them, and in a year you will be kicking my butt because I built pretty airplanes instead of followign this advise,,,

Tim Wescott · « **Reply #9 on:** April 06, 2012, 12:05:00 PM »

You mean ugly like this Nobler that I built before I realized that you build profiles because they don't break as easy and because they're easy to repair, not because they're easy to build? The one that I covered with that roll of International Orange Econocoat that I had sitting around for decades because it's ugly, and nothing -- I mean nothing -- could make that color anything but gawdaful?

I am going to build a bunch of planes, Mark -- that's the whole point of this exercise. Little things like different wing tips aren't going to slow me down much, I don't think.

Bill Little · « **Reply #10 on:** April 06, 2012, 01:20:10 PM »

Hi Tim,

Of course, you can change the clothes on the mannequin as long as you don't go way off the reservation. Make one an open cockpit 1930's version.

BIG Bear
RNMM/AMM

Mark Scarborough · « **Reply #11 on:** April 06, 2012, 01:29:46 PM »

cutting FOUR parts exactly the same, versus cutting Four parts four different ways,,
I vote for clones,, and put colors on them to make them different, heck make one of them international orange,, one neon green, one hot pink, and one,, oh, heck make it chrome,, LOL

just make them fast, repeatable, repairable,, and,,, FLY

Tim Wescott · « **Reply #12 on:** April 06, 2012, 01:51:29 PM »

Quote from: Bill Little on April 06, 2012, 01:20:10 PM

as you don't go way off the reservation.

I think Mark and I just disagree about how far "way off" is.

Quote from: Mark Scarborough on April 06, 2012, 01:29:46 PM

cutting FOUR parts exactly the same, versus cutting Four parts four different ways,,
I vote for clones,, and put colors on them to make them different, heck make one of them international orange,, one neon green, one hot pink, and one,, oh, heck make it chrome,, LOL

just make them fast, repeatable, repairable,, and,,, FLY

OK. Four small profile Genesis clones it is -- I'll save on cutting rudders that way.

Mark Scarborough · « **Reply #13 on:** April 06, 2012, 01:56:57 PM »

lol,
YOU KNOW, if I had not heard, ok so I said,, the same things, I would not find this nearly as entertaining,,
Tim, as long as you are having fun man,, go with it,,

Ultimatly, your GOAL in this hobby decides what direction you take,, if your goal is to chill with us fabuloous awesome guys for a weekend, and play with cool airplanes, then it really does not matter much what you fly,, if your goal is to challange Paul, or Howard, or Norm, or,,,, ad infinitum,, then, well your process will be much different. aside from that, its up to you to decide on the best aproach to reach YOUR goal,,

Just cause I am smarter,, I mean uh,, dumber,, I mean,, just cause I walked the same path you are,, doesnt mean its wrong,,
regardless, I enjoy bantering with you about it,,
did you ever manage to fly the worlds most labor intensive , free, ready to fly that ended up not being ready to fly by your standards flight streak

Tim Wescott · « **Reply #14 on:** April 06, 2012, 02:11:54 PM »

It's a good thing, too, that I'm just way too serious to try pulling your leg.

Paul Taylor · « **Reply #15 on:** April 06, 2012, 03:02:36 PM »

OK this thread has got me wanting to fly my Streak Master.

If the wind lays down this afternoon, I going in search of a flying site close to home.

Soccer fields or BB park....

Tim Wescott · « **Reply #16 on:** April 10, 2012, 03:13:29 PM »

Quote from: Mark Scarborough on April 06, 2012, 11:30:39 AM

TRUST me, I have only recently been there, and honestly am looking at this path again as a way to lower my bottoms,, ( as opposed to the 10,000 calorie a day method of lowering MY bottom,, )
its really really hard to fly something you sweated over and invested love into at dangerous close altitudes,,
I KNOW all of your arguments, I used and still use them,, just do it and make them ugly on purpose,, fly the holy crap out of them, and in a year you will be kicking my butt because I built pretty airplanes instead of followign this advise,,,

OK, to help both of us, I propose a bet:

Looser buys two good yuppie beers (it has to be higher priced than Schludwiller, because I have to drink the gluten free stuff), one for the winner and one for the judge. Winner is whichever one of us shows up with the most pragmatic airplane at next year's Regionals, or the contest of your choice. Randy Powell can judge, if he's willing.

I say pragmatic, because I was thinking of saying ugly, then I started cooking up schemes involving Rustoleum hand-mixed to match gray automotive primer, and mismatched wings with a note in 1/12 scale yellow paint marker saying "'89 Skyray, RW, $50", and airbrushed-on pink fluorescent "spray paint", etc. So, pragmatic, because that won't inspire me to really pull out the stops trying to achieve "ugly" while still having a good-flying plane.

And, just for clarity, by pragmatic I mean that -- in the judgment of whoever we con into doing the judging -- the winner has the best blend of adequate (but not necessarily sterling) performance and least effort to build.

Mark Scarborough · « **Reply #17 on:** April 10, 2012, 03:30:52 PM »

well then, I want my flight streak back,,, cause now that YOU have done all the work, my work load will be minimal,, so least effort,,

alas, now that I have established my self appearance wise, I certainly would be remiss to show up with a less than spectacular finish on an airplane,, all my fans would be so very dissapointed,,

Just sayin,,

so perhaps I will conceed,, or perhaps in a more devious way, I will pay forward a couple more airframes that are "ready to fly" so that you can spend your time with revisions and improvements, and hence be unprepared to compete in this little contest you propose,,

Tim Wescott · « **Reply #18 on:** April 10, 2012, 04:20:19 PM »

Quote from: Mark Scarborough on April 06, 2012, 01:56:57 PM

did you ever manage to fly the worlds most labor intensive , free, ready to fly that ended up not being ready to fly by your standards flight streak

Yes and it flies quite well -- thank you for handing off such a convenient airplane. Except I may have to go and gasp take Dan's Rutherford's advise and put a Hayes tank on it -- the one that's on there cuts out in the cloverleaf, even when there's still a good 1/2 oz of fuel left. If going to a bit bigger engine (I've got the FP 20 on it now) doesn't manage to keep the fuel flung to the outside of the tank, it'll have to be either a new metal tank in the same spot, with a steeper slope to it (more labor), or a Hayes tank on the outside (uuuugly).

John Desrosiers · « **Reply #19 on:** April 10, 2012, 04:57:11 PM »

I carved out a ringmaster fuse to fit a flitestreak wing. Dont know how it will fly but I dont have anything else to do rite now. I hate not haven nothing to do. NO,BUCKS< MODELS.

Tim Wescott · « **Reply #20 on:** April 10, 2012, 05:01:55 PM »

Quote from: John Desrosiers on April 10, 2012, 04:57:11 PM

I carved out a ringmaster fuse to fit a flitestreak wing. Dont know how it will fly but I dont have anything else to do rite now. I hate not haven nothing to do. NO,BUCKS< MODELS.

I feel your pain. The downturn hasn't been kind to me, either. I'm kinda building down my stock of wood, and waiting until the dibs are in tune before I buy covering and such.

Then there's the contract labor dilemma: when you have work you have money but no time, and when you don't have work you have time but no money...

John Desrosiers · « **Reply #21 on:** April 10, 2012, 05:08:56 PM »

AMEN brother

Tim Wescott · « **Reply #22 on:** April 23, 2012, 03:08:15 PM »

The Skyray has 1/4" square spruce for spars. What's the consensus opinion: if I change this to (fairly hard) balsa should I up the size to 1/4"x3/8", or even 1/4"x1/2"? Or should I just use 1/4" square and call it good?

I'm thinking 1/4" x 3/8" if it's really hard balsa, maybe x 1/2" if it's not particularly dense.

Andrew Hathaway · « **Reply #23 on:** April 23, 2012, 03:58:06 PM »

Aren't they 5/16x1/4 spruce in the kit? Either way it doesn't matter, 1/4" sq balsa is plenty. 3/16" sq spruce works fine too, but probably won't survive a crash. Toss the lite ply parts in the garbage, cut 3/32" balsa ribs for all locations. Use full ribs instead of half ribs. Use 3/16" sheet for fixed flaps, the far too soft flaps from a Twister or Banshee kit are about right. I also put the bellcrank mount on the other side of the center rib and flip the bellcrank over. You'll know when it's right because the kit pushrod will still fit, just on the opposite side of the fuselage. More important put the pushrod in the inside hole. In stock form, the controls are way too fast for any precision. Change the ugly wing tips to suit, and with everything else left stock they fly OK. I'd probably use the Flite Streak airfoil if I was building a Skyray from scratch.

Tim Wescott · « **Reply #24 on:** April 23, 2012, 04:49:25 PM »

This is definitely from scratch, and now that you smack me upside the head with it, yes, the spars are 5/16 x 1/4.

Surviving a crash -- or at least coming through one in rebuildable condition -- is high on my list of desirable qualities, so I'll probably go to 3/8" x 1/4" on the spars.

Interestingly enough, my controls are set up "stock", and I like it just fine. Of course, I've got an adjustable handle with the lines about 2-1/2" apart, that may be the difference.

Andrew Hathaway · « **Reply #25 on:** April 23, 2012, 06:11:54 PM »

The kit spars are serious overkill, the weak link is a tie between the ply doublers/ butt-joint at the center and the added weight of the heavy spruce/lite ply wing that ends up coming forward in a crash, which breaks the wing at the center section. Worse yet the spruce and lite ply don't break clean, so they're more difficult to repair. All balsa construction is lighter, so the wing is less likely to be destroyed in a crash. Plus using normal 36" sticks, you can put the splices out near the tips where there's less structural demand. Using a nice angled splice instead of the butt joint and ply doublers saves more weight, and is plenty strong.

Narrow line spacing at the handle is ok, but most handles that are capable of going that narrow end up having overhang. I slow the controls down at the bellcrank so I can use a handle with Hot Rock spacing. It can always be made faster at the control horn externally.

If you want a plane you can fly into the ground, dust off, change prop, and fly again... Look into Sig Koverall. It's a synthetic cloth that goes on with dope, once the edges are stuck, heat shrink out the wrinkles, then you can finish it like silkspan or silk. In a crash, it won't shatter like iron-on plastic or silkspan. If the crash is REALLY violent, the dope will shatter off the covering and it leaves you with a nifty synthetic cloth bag full of broken parts. It's good stuff, just heavy, and takes a bit of dope to fill the weave.

Tim Wescott · « **Reply #26 on:** April 24, 2012, 07:49:54 PM »

Quote from: Andrew Hathaway on April 23, 2012, 06:11:54 PM

Plus using normal 36" sticks, you can put the splices out near the tips where there's less structural demand. Using a nice angled splice instead of the butt joint and ply doublers saves more weight, and is plenty strong.

That's what I would have done before yesterday. But all that wing parted cleanly in the center -- with the exception of the ply spar doublers, the center section sheeting, the tip weight, and a few cracks is the ribs, nothing broke in the wing. Nothing. The wing is back together now, waiting to be covered and slipped back into the fuselage.

I don't think I'll use the "all 24" wood" construction on purpose, because I think that it's probably a bit of a freak that this plane got just the sort of blow that made it break in such an easy-to-fix way.

But it sure makes me think.

Tim Wescott · « **Reply #27 on:** April 24, 2012, 07:54:34 PM »

Here's the current thinking. Keep in mind that -- no matter what it might look like -- it's aerodynamically just a Skyray with a tapered wing. Any resemblance to previous National's winning airplanes is entirely intentional.