Skyray trim??

[Chris Fretz]

I stated practicing beginner pattern. It seems the Skyray was flying with the inboard wing tilted down. The engine setting ended up going too rich to stunt with the inboard tank I was trying. So I addedt 3/4oz weight in the wingtip. Second flight seemed to do the same thing with the inboard wing tilted down, but upside-down it seemed level. Does this mean add more weight or the wing is warped? Also in the top of the loops it was doing some wiggle. Of course it started to rain so I didn't have much time to study it, I'm pretty sure the lines stayed tight throughout. Any suggestions?

Not a 100% sure I'm doing the patten right.

[Motorman]

It's a wing warp. Just twist the wing as you re-shrink the covering and go fly it again to check.

MM

[Chris Fretz]

It's a wing warp. Just twist the wing as you re-shrink the covering and go fly it again to check.

MM

I guess it could be either side that is warped?

[Brett Buck]

I guess it could be either side that is warped?

   Put the airplane nose down on your foot, and then, sighting down the length of the fuselages, center the trailing edge between the upper and lower surfaces at the wing root. Without moving your head, look where the TE lines up between the upper and lower surfaces at the tip. If the TE is not centered from root to tip, you have a warp. Obviously, straighten only the side that is warped. Given the amount of tip weight it took and still had a roll angle, I expect it's going to be pretty easy to see.

     Brett

[Carl Cisneros]

yepper
thats the beginners pattern you are doing. I am practicing it also.
At the finish of the square loop, just fly straight and level out of the bottom.
Only 2 horizontal 8's.
Do the INSIDE loop portion of the over head figure 8 FIRST.

just a wee bit rich but the plane is doing the pattern with out any problem to me.
Nice Flight.   

What Brett said about the warp.

Carl

[Tim Wescott]

Yes to everything that's been said.

If the wing is level one way and low the other then you have both too much tip weight and a warp.  Too much tip weight is better than not enough, but you'd still like it to be closer.

If you're comfortable doing it, to determine level hold the handle up so that you're sighting along the handle to the plane.  You want the wings to appear to extend straight out from your hand both inverted and upright.  You also want loops and whatnot to feel right, but that needs to wait until you develop some finesse.

As to the actual flying, that flight would definitely get you a trophy in beginner's around here -- of course, we usually have more trophies than pilots in beginner, so ...

Actually, the individual maneuvers look good enough for Intermediate the way we do things around here -- that, plus the fact that you can fly inverted, makes me think that you should be thinking about learning the whole pattern.  If you haven't done a contest before do go ahead and start with Beginner -- people will be more forgiving of fax-paus, and you can defer learning to make the engine run for just the right amount of time.  But you could move up to Intermediate soon.

The Skyray's a good choice of plane.  It won't start holding you back until you're well into Intermediate, and folks have scored over 500 points with 'em.  I'd have recommend a 25LA for it (it'll be a better plane with that engine), but if it's working with your Fox then go for it.

[Chris Fretz]

The Skyray's a good choice of plane.  It won't start holding you back until you're well into Intermediate, and folks have scored over 500 points with 'em.  I'd have recommend a 25LA for it (it'll be a better plane with that engine), but if it's working with your Fox then go for it.

I don't currently have a LA.25 as of yet.  But my Skyray has a Testors McCoy Series 21 .35 on it not a Fox. So far I hate messing around with Fox's.

[Tim Wescott]

I don't currently have a LA.25 as of yet.  But my Skyray has a Testors McCoy Series 21 .35 on it not a Fox. So far I hate messing around with Fox's.

I believe that if you have a good one the McCoy is a much better engine.

[Chris Fretz]

I believe that if you have a good one the McCoy is a much better engine.

I do really like these Series 21 engines, they always run good for me.

[Chris Fretz]

As to the actual flying, that flight would definitely get you a trophy in beginner's around here -- of course, we usually have more trophies than pilots in beginner, so ...

Actually, the individual maneuvers look good enough for Intermediate the way we do things around here -- that, plus the fact that you can fly inverted, makes me think that you should be thinking about learning the whole pattern.  If you haven't done a contest before do go ahead and start with Beginner -- people will be more forgiving of fax-paus, and you can defer learning to make the engine run for just the right amount of time.  But you could move up to Intermediate soon.

Thanks! I've never done a contest so I figure I'd be better off starting from the beginning. Besides maybe I can win an move up and feel good about moving up instead of being stuck in intermediate forever

[Chris Fretz]

yepper
thats the beginners pattern you are doing. I am practicing it also.
At the finish of the square loop, just fly straight and level out of the bottom.
Only 2 horizontal 8's.
Do the INSIDE loop portion of the over head figure 8 FIRST.

just a wee bit rich but the plane is doing the pattern with out any problem to me.
Nice Flight.   

Thanks for pointing those things out, I'll try to fix that next time. Was the first day I tried doing the actual pattern.
Good luck at beginner

[Chris Fretz]

This airplane has been sitting in a attic getting hot an cold for 20yrs. I cut the stabilizer out an re glued it cause it was crooked. When I get a chance I'll look for this warped wing. I hope I can get it fixed.

[john e. holliday]

The video of the flight the plane looked like it was doing okay.  I had an ARF Flight Streak that had a wing down inboard upright and opposite inverted.   We double checked for warps and even measured.  Wound up putting a trim tab on out board wing.   Have no sound, but if the McCoy is running good and your happy with it, stay with it.   

[Tim Wescott]

This airplane has been sitting in a attic getting hot an cold for 20yrs. I cut the stabilizer out an re glued it cause it was crooked. When I get a chance I'll look for this warped wing. I hope I can get it fixed.

Monocoat or silkspan?

If it's Monocoat, then what Brett said -- twist it a bit opposite of the problem and hit it with a heat gun.

If it's silkspan, then you need to involve some boiling water -- I've never done it, but I think the method is to hold it over a big pot of boiling water for a while to get it warm and moist, then hold in opposite twist as it cools.

Either way, the Skyray wing construction makes twist removal easy.

[Chris Fretz]

Monocoat or silkspan?

If it's Monocoat, then what Brett said -- twist it a bit opposite of the problem and hit it with a heat gun.

If it's silkspan, then you need to involve some boiling water -- I've never done it, but I think the method is to hold it over a big pot of boiling water for a while to get it warm and moist, then hold in opposite twist as it cools.

Either way, the Skyray wing construction makes twist removal easy.

Luckly it is Monokote. Hopefully I'll get a chance to look at it tommorow.

[Chris Fretz]

Looks to me like the outboard wing is bowing down.

[Brett Buck]

Looks to me like the outboard wing is bowing down.

   That's exactly how you should look at it, and yes, for sure, the outboard TE is warped down, quite a lot. That much is certainly enough to cause your issue. The inboard might be warped up a touch, but I wouldn't swear to it from a picture.

    Brett

[Chris Fretz]

Will twisting that outboard wing and putting a iron to it work?

[Terry Caron]

Easier to use a heat gun if you have one, but yes, opposite twist with heat, held 'til cool, should straighten it for you.
Maybe a couple or 3 tries. 

Terry

[Brett Buck]

Will twisting that outboard wing and putting a iron to it work?

   If that's what you have, go ahead. I would use a heat gun, but with Monokote you would be surprised how much it will move. These constant-chord wings with no real twist resistant structure are held in alignment mostly with the covering.

    Brett

[Tim Wescott]

Looks to me like the outboard wing is bowing down.

Yeppers.  That's a severe warp.  You want it so close to perfect that you can't see it, and even then you want to be someplace quiet with strong light, and you want to take your time looking.

As Brett said, the structure of the wing means that the covering is holding it against twist -- in return for the structure depending on the covering for it's strength, it'll survive a crash much better, so it's not a bad trade, overall.

[MikeyPratt]

Looks to me like the outboard wing is bowing down.

Man that is a warp and half.  I wouldn't have flown it that way in the first place, I'm surprised it is still in one piece.  Do what ever it takes to get the warp out, and make sure there is about 3/4 of an ounce of tip weight in the out board wing tip.  To much tip weight is not good either so make sure it right!  Also, now would be a good time to remove most of the rudder offset.

Later,
Mike Pratt

[Chris Fretz]

 

Man that is a warp and half.  I wouldn't have flown it that way in the first place, I'm surprised it is still in one piece.  Do what ever it takes to get the warp out, and make sure there is about 3/4 of an ounce of tip weight in the out board wing tip.  To much tip weight is not good either so make sure it right!  Also, now would be a good time to remove most of the rudder offset.

Later,
Mike Pratt

ha ha an I already took some offset out a couple weeks ago. How many degree of offset do you recommend designer?

[Tim Wescott]

  ha ha an I already took some offset out a couple weeks ago. How many degree of offset do you recommend designer?

I'm not Mikey, but I would recommend exactly 0.  I set up everything that way and they all fly fine (and I'm flying in Expert -- I'm not winning in expert, but I don't belong in Advanced any more).  When you get to the absolute expert level you may want to make a tweakable rudder and move it one way or another, but leave it at 0 until then.

[Chris Fretz]

I'm not Mikey, but I would recommend exactly 0.  I set up everything that way and they all fly fine (and I'm flying in Expert -- I'm not winning in expert, but I don't belong in Advanced any more).  When you get to the absolute expert level you may want to make a tweakable rudder and move it one way or another, but leave it at 0 until then.

We all know there isn't adjustable leadouts on this airplane right? Still shooting for 0? Wile we are on the subject how about engine offset?

[Steve Helmick]

Haven't read the Beginner rules yet this year, but I know there is no Inverted, so I'm not certain if you're allowed to exit the Inside Loops to inverted flight or not. I am certain that your exit from the H8 wasn't correct. If you don't enter and exit correctly, you shouldn't get Pattern Points, but sometimes Judges get a little slack with Beginner, particularly if you are the only one. 

Otherwise...your engine comes on pretty strong on outsides, so I'd suggest lowering the fuel tank about 1/8". I admit that I prefer making a "strong" change, so that I'll know for sure that something happened in the correct direction. Others will suggest changes of 1/64" at a time, I'm sure, but I would rather work my way back to "perfect" from "too far". Inverted speed seemed pretty much the same as upright, which is interesting, but NOT nearly as important as engine response through the maneuvers. A good way to quickly test the tank height is "lazy 8's", but honestly, it's been so long since I have done a Lazy 8, that I tend to get confused and almost crash. One of the really GOOD things about flying the pattern is that you'll crash MUCH LESS, once you get it figured out.    Steve

[Tim Wescott]

The current rulz say you can come out of the inside loops right side up or inverted.  I think they want it to be easy for someone who's scared of inverted, but let people get used to coming out of the loops "correctly" if they can fly upside-down without fear.

[Steve Helmick]

Cool. That's a fine idea. OTOH, I firmly believe that anybody who can fly inverted (without fear) should really enter Intermediate, whether he/she can do all the tricks or not.

See you at the Judging Clinic tomorrow, Tim. Don't forget to bring the Cheese & Kisses.  Steve

[RknRusty]

Chris, you've got a lot of good things going on in your flying, and you are open to trimming advice and getting good advice here. All I can add, and I think you know it, is there's more to Beginner than just the flight. It's about getting your routine figured out. That means metering your fuel and getting the plane placed where you want to take off, not just where everybody else does. And if you're not comfortable where the judges are with respect to the wind, asking them to Please move to where you think they'll be opposite your stunts. Then priming, signaling the judges, getting cranked and running like you want it. After that, it's all flying. That's what Beginner is all about, and it's still cool to bring home a trophy, there's no asterisk saying "He didn't have anyone to beat." And your Mom and friends will think you're an expert Lol. Well, at least mine does.

And once you've done it once, for the rest of your life you can always say, "I flew competitive Control Line Aerobatics." And nobody can take that away.
Good luck, and have fun.
Rusty

[Brett Buck]

Man that is a warp and half.  I wouldn't have flown it that way in the first place, I'm surprised it is still in one piece.  Do what ever it takes to get the warp out, and make sure there is about 3/4 of an ounce of tip weight in the out board wing tip.  To much tip weight is not good either so make sure it right! 

   On the other hand, in this case the excess tip weight in the only thing that kept it from chasing him around the field, so starting with too much and working it down is at least safe, if not optimal.

    Brett

[Chris Fretz]

   On the other hand, in this case the excess tip weight in the only thing that kept it from chasing him around the field, so starting with too much and working it down is at least safe, if not optimal.

    Brett

I've had 1oz in the tip for many flights, I just recently made it 1 3/4oz

[Chris Fretz]

I think it might be better now? Amazing how much you can move it!

[Tim Wescott]

See you at the Judging Clinic tomorrow, Tim. Don't forget to bring the Cheese & Kisses.  Steve

I won't be making it, due to the press of busy-ness.  Wish I could.

[MikeyPratt]

  ha ha an I already took some offset out a couple weeks ago. How many degree of offset do you recommend designer?

Just enough off-set to make sure (1 degree) it's not pointing into the circle.  I sure hope this all works out for you because they are great flying models. 

Later,
Mikey

[Tim Wescott]

We all know there isn't adjustable leadouts on this airplane right? Still shooting for 0? Wile we are on the subject how about engine offset?

Zero.  And I'm pretty sure that the kit leadout positions are either right on or a bit back, which is safer than too far forward.

It's worth cutting up the wing tip to make the leadouts adjustable, or at least put them where Line III says to.  If not now, then after the next crash.

[Chris Fretz]

Welp she flew a little better but still not flying level.

[Gerald Arana]

Welp she flew a little better but still not flying level.

Keep working on it and soon it will be right!

Jerry

[Brett Buck]

Welp she flew a little better but still not flying level.

    Check that the warp did not come back, but look closer. At the end, tweak it until the wings are at the same angle upright and inverted, regardless of what you see.

   Brett

[Tim Wescott]

    Check that the warp did not come back, but look closer. At the end, tweak it until the wings are at the same angle upright and inverted, regardless of what you see.

+1.  Mess with it until it's right.  When you have flaps you'll find yourself tweaking them slightly to get the same effect.

[Fredvon4]

I have a similar problem with a Mike Griffin Ring Master with adjustable lead outs... Sean McEntee is flying the trimming flights and we had no way at he field to pull out a warp so he super-glued a trim tab and it helped but not enough

WX here has sucked sine the late April maiden flights

At my place we tweaked the wing and I heat gunned while Sean held the twist... looked good THEN

BUT! I am having roller coaster humidity with the every 5 days new WX front and rain.... Relative humidity of 30% one day and 95% the next... being a Mono coated ARF with open ingress via the adjustable leadouts I postulate that my constantly changing wing warp is humidity related so in the process of putting light aluminum (beer can) trim tabs on both wings

This is my first RM/Stunt plane and I have built myself many combat balsa planes ---and when I get them built I coat all balsa with Nitrate dope (I know, heavy but what my dad taught me before putting on watered wet silk)...thus I suspect Mike just "koted" the wing and all balsa is bare...being very width and length changeable from moisture...grrrrr

OK too much rambling... can you PAC guys steer the WX a bit north please...I prefer hot and 30% humidity...grin

[RknRusty]

EDIT: Fred posted while I was writing this, but here are my thoughts anyway:

If it's still different between upright and level, and if the wing is just too stubborn to dial it in perfectly, you can always put a trim tab on the outboard side. I know it's better not to have to brute force it like that, but at my intermediate level of flying it gets the job done. I carry an assortment of aluminum strips bent to varying degrees and tape it on near the tip with scotch tape. Clean the area thoroughly with(if xx-kote) acetone and it will stay permanently if necessary.

This is a maximum width tab, you wouldn't want one any larger.
This is a Skyray built mostly to Brett's recommendations, other than the Streak looks.

[Chris Fretz]

Which side would you pick on first since they both appear straight? Mess with both sides or one at a time?

[RknRusty]

If you mean where to put a trim tab, only on the outboard wing.

[Chris Fretz]

If you mean where to put a trim tab, only on the outboard wing.

No for now I mean bending with a heat gun. I'll try a trim tab if all else fails.

[Tim Wescott]

Which side would you pick on first since they both appear straight? Mess with both sides or one at a time?

It depends on the size of the tweak needed.  If you absolutely cannot tell, and if the tweak you're going to deliver is small, then just tweak one side.  If you're going to tweak a bunch, then ask why you can't see anything!

[Howard Rush]

A trim tab is a poor alternative to a straight wing.  Unlike some things that you can count on to add together predictably--weights on a spring, resistors in a circuit, for example--you can't count on a trim tab to balance a wing asymmetry.  That's because the amount that lift will vary with angle of attack will start to differ from one side to the other as angle of attack gets high enough to do loops.  You can counter a warp with a trim tab in level flight, but the airplane may roll in mild maneuvers and may stall one-wing-first in hard corners.  A warp in a rigid-structure wing, where about all you can do is tweak the flaps differentially, puts you in a pickle, but the flexible structure of a Skyray or Ringmaster wing is easy to dewarp.  It's not as easy as adding a trim tab, but well worth the effort.

If the wing looks OK from the back, you might eyeball it from the end to see if there is a curve in the trailing edge or if the trailing edge is bent up or down.

[Dennis Moritz]

Find a combat guy. If you can. Like Howard.


Sent from my iPhone using Tapatalk

[Chris Fretz]

Looking down the trailing edge of the inboard wing I see a hump bowing up. Got that straight so I'll give her another try. Hopefully tomorrow.

[RknRusty]

A hump in a wing can't be good. But good for you for sticking to it, that's what it takes in this sport. Howard is right, as several have mentioned, the tab is a last resort. But in a case where you're just beginning to learn the basics of aerobatics, if all your efforts fall short and you finally must do it, it can keep you flying long enough to build your next better straighter plane with all of your newfound knowledge. One that will help you learn to fine tune your shapes without having the plane's shortcomings burned into your developing muscle memory. It seems that's what I am doing right now too. Flying patterns and sometimes winning with an old beater while finishing my build of a proper stunt ship.

I recommend on your next wing to build in shear webs to help hold it rigid and straight. And to reduce flexing under heavy loads. I put webbing in the trailing edge of the Osprey, my Skyray/Streak-bash I posted earlier(still had a tab, but hey, I'm new at it too). Or you can put them between the main spars too. Here is a very good reference website for aerodynamic building techniques.
http://www.airfieldmodels.com/information_source/math_and_science_of_model_aircraft/rc_aircraft_design/shear_webs_in_model_aircraft_wings.htm

I usually need to look up something on that site every time I'm building a new plane. The search button is at the bottom of the left menu column, and they cover every part of building a plane.

Hope that helps,
Rusty

[Tim Wescott]

I recommend on your next wing to build in shear webs to help hold it rigid and straight.

Shear webs help, but that's as far as you want to go with a nice rigid wing structure until you're not crashing all the time.

The bad thing about the Skyray wing structure is that the covering holds it rigid, you have to tweak it to get it straight, and it's always warping up again.  The good thing about the Skyray wing structure is that the covering holds it rigid, and when you thump it hard into the ground the covering bursts and the damage to the actual wooden structure is minimal.