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Sig Skyray, Canadian Edition....

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Happy Sig Skyray, Canadian Edition....

Post  NEW222 on Tue May 05, 2015 8:12 pm

Hi all. Just a little report from here. Been getting things ready lately to get back into the swing of things this year. So, I find my neglected Skyray shelved very well, donning its Black Widow engine. This was built circa. 2000, and thought it flew before, but now cannot remember. So, I pull it down from its hiding spot and give it a once over. Notice wingtip weight is missing (never applied which I drew my conclusion about never being airborne after thinking it was), so I epoxied 2 pennies to the outboard tip. Engine was very stiff. So, I cradle it and fill it anyways. 3 or 4 flips later, it let out a nice braaaap. So I wind it just shy of a turn and it fired again, only thing was it did so right into my thumb! Yep, blood everywhere. My old man is laughing at me telling me I should be using a glove. So this is taking place as I am walking to the shop to get a rag to wipe my thumb and plane of blood. In doing so, I hear the familiar braaaap followed by a quick slurry of profanity by the one telling me of using a glove. He he. So after getting 2 complete tanks through, we march over to the park in the corner. Fire it up and attempt take off. Up she goes followed by a beautiful figure 9! Start it again and had nothing but the same luck. So after 2 attempts, I now have a Skyray with a speed prop. This ended my day so off to the shop to finish off another plane for the next attempt when weather permits. Just thought I'd share my little story with you all.
The damage to my thumb today comes after opening up my left pointer yesterday working on my sleigh for behind the snowmobile, and squishing my 'bird finger' in the metal brake at work last Friday. Bad week.

[img][/img]

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Happy Re: Sig Skyray, Canadian Edition....

Post  TDbandit on Tue May 05, 2015 8:43 pm

Nice, it's gonna move along with that Black Widow on it. Smile BTW since you said that it's been sitting for a while, you might want to check the wing for warps. My old blue one sat for a long time and I discovered that it had a warp took me a bit to steam it out. My TD .051 loves fingers, I've gotten more band-aids due to that eternally angry little monster than any engine I've owned lol Ya haven't really run a cox until it's ate your finger once or twice!
(Bandit)
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Tue May 05, 2015 9:28 pm

Thanks for the tip on the warps. I will definitely look at it for any. I m not sure how they would come out and or do damage to the plane as it is just spry painted. Thank you.
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Happy Re: Sig Skyray, Canadian Edition....

Post  Sig Skyray on Wed May 06, 2015 7:01 am

Hey New, at least she's still in one piece...  I'm hoping for that luck when I test my 1/2A Skyray I'm building now.  I'll maiden her with a Babe Bee and strap on the black widow once she's balanced and trimmed.  I like that black look. Sleek.
Those look like some heavy lines.
Greg
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Wed May 06, 2015 5:51 pm

Actually, they are quite a tough bird. Just speaking from past experiences. Now that you mentioned starting with a Babe Bee then off to the Black Widow, you have me thinking. I am back to thinking I may have never flown it before. I will now have to also go out and balance it just to see. And lines. Let me tell you about lines. Yes, they are thick. Way back when, around 1988-1990 we had a Testors Fly-Em' plane. Sometime back then, I believe a line broke. So instead of the proper expensive Dacron from the hobby shop, I believe my dad and I went to the hardware store and bought a huge roll of this string of sorts. So we installed it on the plane back then, and apparently I had done so with this one as well. So much has escaped my memory about this plane, that every time someone comments, something else come back to my memory. And yes, they are very draggy, but they do fly with them.
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Tue May 12, 2015 7:47 pm

Ok. While taking pictures, I did a quick balance. Is it just me, or are these things normally tail heavy? It appears to be so with my model, which I believe led it to go straight up with no control and do a noseplant and figure 9. I guess I will have to add some nose weight. Even with the Black Widow up front. I do not recall my last one being like that. Anyways this solidifies the theory that it had NOT been flown before as it would have never flown with it being so out of balance. Thanks for all the tips.
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Happy Re: Sig Skyray, Canadian Edition....

Post  RknRusty on Tue May 12, 2015 8:52 pm

Well y'all answered all the questions I was going to ask. Fix the wing warp and make the nose heavier. Where does it balance now? Make it about 10% chord and try again. If you switch between a BW and a Babe Bee, it'll need re-balancing again.
Rusty

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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Tue May 12, 2015 9:54 pm

Thank you. I will just leave the Widow up front and add weight. I balances at approximately 1 1/4" - 1 1/2" from the leading edge. The plans call for balance point from the leading edge to 5/8" back. As for the wing, it is actually very flat with very slight up at the inboard leading edge, and I do mean slight. Thank you.
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Tue May 12, 2015 9:55 pm

After looking at the pictures I had posted, I do see that it looks like the wing has a warp to it. But it isn't.
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Happy Re: Sig Skyray, Canadian Edition....

Post  RknRusty on Tue May 12, 2015 10:13 pm

NEW222 wrote:Thank you.  I will just leave the Widow up front and add weight.  I balances at approximately 1 1/4" - 1 1/2" from the leading edge.  The plans call for balance point from the leading edge to 5/8" back....
Yeah, that explains it. You can get a heavy prop stud and nut from Bernie. That'll help some. Gets the weight out front.

http://coxengines.ca/cox-.049-hub-nut-balancing-weight.html

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Happy Re: Sig Skyray, Canadian Edition....

Post  Cribbs74 on Tue May 12, 2015 10:14 pm

Something looks amiss with the bellcrank. I am not trying to pick the plane apart, just don't want you to have a bad day.

The fat part of the bushing should be on top, washer on bottom, or top and bottom allowing the bellcrank to pivot freely. It may be that way and the pics are just throwing me. I apologize if you do have it set up correctly. The picture just appears to have the bellcrank angled upwards.

Ron
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Tue May 12, 2015 10:42 pm

I will look that over tomorrow, but i think it is my trick photography skills. Thank you for all the help. I do not mind if others see something or suggest something, as it may be something important I had overlooked. Better wasting a few minutes being safe rather than sorry. Thanks.
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Happy Re: Sig Skyray, Canadian Edition....

Post  gcb on Wed May 13, 2015 12:11 am

Looking at those controls, it appears that you have some built-in up elevator control. With the bellcrank at 90 degrees to the wing, the elevator should be at neutral. That may explain the figure nines on take-off.

Also consider placing the pushrod in the bellcrank hole closest to the pivot to reduce the amount of control until you get used to flying your Skyray.

Next time consider drilling the bellcrank mounting hole with the rest of the control system already installed and the elevator at neutral. That helps lessen the chances for built-in up or down.

Skyrays are excellent planes. I have two plus two knock-offs. One of the knockoffs has a warped wing. :-(

George
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Happy Re: Sig Skyray, Canadian Edition....

Post  TDbandit on Wed May 13, 2015 4:57 pm

gcb wrote:Looking at those controls, it appears that you have some built-in up elevator control. With the bellcrank at 90 degrees to the wing, the elevator should be at neutral. That may explain the figure nines on take-off.

Also consider placing the pushrod in the bellcrank hole closest to the pivot to reduce the amount of control until you get used to flying your Skyray.

Next time consider drilling the bellcrank mounting hole with the rest of the control system already installed and the elevator at neutral. That helps lessen the chances for built-in up or down.

Skyrays are excellent planes. I have two plus two knock-offs. One of the knockoffs has a warped wing. :-(

George
I've got a warp in my old Skyray and they are hard to remove, I got most of the warp out by holding the effected wing panel over a pot of boiling water while twisting it in the opposite direction of the warp. Worked ok still not all out but made er flyable.
George is right I would place the pushrod in the inner hole of the bell crank to tame er until you get used to it. It flys good the way it is with the tail heaviness just makes it a bit twitchy and hunts a little but makes for a lively little stunter. The heavy hub that rusty mentioned will help it's twitchiness. (Bandit)
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Wed May 13, 2015 6:01 pm

Thank you for the tips all. I really like the one about drilling the bellcrank mounting hole prior to installing as to getting it perfectly, or as best to, the controls in neutral.
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Happy Re: Sig Skyray, Canadian Edition....

Post  getback on Thu May 14, 2015 6:21 am

New222 is the elevator warped also even as was said thee is up in neutral looks as if the inboard side is higher up than the other ? I have a warped stuntman I want to getback in the air , and some bats I think I am going to recover . \\\ may have to build me one of those skyrays I like the look Very Happy
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Happy Re: Sig Skyray, Canadian Edition....

Post  gcb on Thu May 14, 2015 8:44 am

getback wrote: ...may have to build me one of those skyrays I like the look Very Happy

getback,
They are excellent little planes. The instructions explain how to set-up the controls for minimum movement for a beginner and how to increase movement for more control as you progress. The wood in my two kits was excellent. Hint...trace the parts on back of the plans in case you break something bad enough that you must replace it. Easier than taking measurements from the broken part.

SIG did their homework.

George
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Thu May 28, 2015 8:39 pm

Ok. Well, I finally had a chance to play with my Skyray again, and I found something puzzling to me. Firstly, I removed the linec completely from the bellcrank. I do not know how the lines got that twisted up, and reversed on the handle. Secondly, I believe that I had mentioned earlier that it was a bit nose heavy. Well, I pushed a pin through the fuselage in the 'canopy', on or immediately after the wings leading edge. Well, a 'bit' is an understatement. To get it in proper balance, I had to put just under 4 oz of lead on the nose immediately behind the engine mount? This does definitely not sit right with me. So, if anyone here may be able to help me figure this out, it would be greatly appreciated. Thank you.
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Thu May 28, 2015 9:18 pm

One more post. I will move my pin back to the max c-of-g at 5/8" behind the leading edge than retry to balance it and see how much it will now take. I will keep you all posted.
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Happy Re: Sig Skyray, Canadian Edition....

Post  pkrankow on Thu May 28, 2015 9:34 pm

Whip up a pendulum CG device. You need to cradle the plane and hang the pendulum from the same point, being fancy is not important. I used a coat hanger, some yarn, and a broken propeller for my first one. I used rope and screw eyes for my next one.
https://www.coxengineforum.com/t5934p20-3d-printing

4 oz of nose weight is insane. I would space the engine forward using plywood spacers until it was close, leave a small cavity in the spacers to be a nose weight box for fine tuning.

Phil
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Happy Re: Sig Skyray, Canadian Edition....

Post  NEW222 on Thu May 28, 2015 9:54 pm

Just back inside. I think I can now get away with 2oz on the nose now with balance at 5/8" back from the leading edge.
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Happy Re: Sig Skyray, Canadian Edition....

Post  Ken Cook on Fri May 29, 2015 4:19 am

If your suggesting 2 oz of weight on the nose of the plane there's something wrong. A Skyray built in stock form is tail heavy slightly. I would say tail heavy for the beginner. I would put no more than a 1/4oz of lead on the nose and that's probably 1 gram to heavy. Ken
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Happy Re: Sig Skyray, Canadian Edition....

Post  RknRusty on Fri May 29, 2015 10:20 am

New, were you heavy handed with the paint on the tail and rear fuselage? If so, you could strip it and give it a shot of polyurethane, and forget about the looks until after you've got it successfully flying. And then it might balance more easily.

Then you can name it something like "Ugray". And write on the tail, "My other plane is beautiful."
Rusty

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Happy Re: Sig Skyray, Canadian Edition....

Post  Cribbs74 on Fri May 29, 2015 10:47 am

2oz is a lot of weight. Looking at that plane it should be slightly nose heavy already due to the stunt tanked bee up front.

Have you flown it as is without the weight? You may find it to be just right. Worst case if you add the 2oz it will still fly, but will be extremely unresponsive.


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Happy Re: Sig Skyray, Canadian Edition....

Post  gcb on Fri May 29, 2015 1:35 pm

NEW222, what did you use to paint your Skyray?

Whether you use dope or rattle-can paint the process is much the same. First layer or two are to seal and smooth the surface. These layers are almost completely sanded off. Top layer is for color.

As folks previously mentioned, most Skyrays come out nose heavy so the paint must be heavy.

Note that any weight you add will decrease performance so weight should be placed as far forward as possible so don't disregard the idea of using a heavy spinner or adding spacers to get the engine further forward...or both.

Good luck.

George
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