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Ordered a 1/2A Skyray kit

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Re: Ordered a 1/2A Skyray kit

Post  TLAnderson on Sat Sep 02, 2017 8:10 pm

roddie wrote:
If you haven't flown it yet.. consider fueling the tank only 1/2 way for the 1st flight.. just in case you have any trimming-issues. One minute can seem like an eternity if the model is hard to control.

I don't have any experience with the wedge tanks, but I did run the engine once and it didn't run very long. It seems that unless the plane is in the air, and centrifugal force is holding the fuel to the outboard side of the tank, that the pickup tube would be sucking air after the fuel level dropped below about a half tank.
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Re: Ordered a 1/2A Skyray kit

Post  roddie on Sun Sep 03, 2017 12:20 pm

TLAnderson wrote:
roddie wrote:
If you haven't flown it yet.. consider fueling the tank only 1/2 way for the 1st flight.. just in case you have any trimming-issues. One minute can seem like an eternity if the model is hard to control.

I don't have any experience with the wedge tanks, but I did run the engine once and it didn't run very long. It seems that unless the plane is in the air, and centrifugal force is holding the fuel to the outboard side of the tank, that the pickup tube would be sucking air after the fuel level dropped below about a half tank.

You are correct.. but the angle of the fuselage/tank while the model is on its wheels/tailskid will place more fuel at the rear of the tank (where the pick-up is) than the front.. giving you some extra run-time on the ground with a half-tank of fuel. Your "pin-stooge" could influence this though. If it orients the tail "high".. the tank-angle will be closer to level. Also; if you're link isn't "rigid" (IE; a string-loop or flexible wire..) the tail might "rise" with the pull from the running-engine.

You can check the angle beforehand by pinning the model into the stooge and observe the tank's angle. If using a flexible-link; gently push the model forward to see "if" and how-much the tail comes up when the link becomes taught.

I tend to be way too "OCD" concerning these things. It might help you out on your first flight(s) though. You won't need to worry about this later-on when launching with a full-tank.

Good luck! Smile Thumbs Up



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Re: Ordered a 1/2A Skyray kit

Post  TLAnderson on Mon Sep 04, 2017 5:26 pm

Well..Here she is. Looking as pretty as it's going to get. I think it's ready to fly. I made up some 35' spiderwire lines today, put on a tip weight, checked the balance. Can't think of anything else.













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Re: Ordered a 1/2A Skyray kit

Post  David Ingham on Mon Sep 04, 2017 5:38 pm

It looks very nice.
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Re: Ordered a 1/2A Skyray kit

Post  Cribbs74 on Mon Sep 04, 2017 5:51 pm

I like your tip weight. Go fly it!
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Re: Ordered a 1/2A Skyray kit

Post  roddie on Mon Sep 04, 2017 8:19 pm

Hope you got a chance to fly today. The model looks great! Thumbs Up
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Re: Ordered a 1/2A Skyray kit

Post  Marleysky on Mon Sep 04, 2017 8:27 pm

Nice wing tip weight! What is it? My guess is 38special, Hornady Critical Defense 110gr?

So, it looks good, should fly good too! RC Plane
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Re: Ordered a 1/2A Skyray kit

Post  TLAnderson on Mon Sep 04, 2017 8:47 pm

Marleysky wrote:Nice wing tip weight!   What is it? My guess is 38special, Hornady Critical Defense 110gr?

So, it looks good, should fly good too! RC Plane

It's a .32 cal 85 grain Hornady XTP. Weighed about the same as two pennies, so I thought "Why not?" Cool
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Re: Ordered a 1/2A Skyray kit

Post  Cribbs74 on Mon Sep 04, 2017 10:01 pm

1/4 oz is usually what is required for 1/2A. If the outboard wing lifts add more. It will be hard to tell at 1/2A speeds, unless it comes in on you Very Happy

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Re: Ordered a 1/2A Skyray kit

Post  TLAnderson on Mon Sep 04, 2017 10:14 pm

Cribbs74 wrote:1/4 oz is usually what is required for 1/2A. If the outboard wing lifts add more. It will be hard to tell at 1/2A speeds, unless it comes in on you Very Happy


Good to know. The Skyray instructions from Sig just say to glue two pennies under the outboard wing, so I was just going by that. I have more bullets if needed. Smile
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Skyray First Flights

Post  TLAnderson on Thu Sep 07, 2017 12:03 am

Well...got 'er in the air tonight. Had some glitches, but it does fly.



In the photo below, I'm turning the handle over...picked it up upside down Embarassed






Flight characteristics seemed pretty good, wings looked level.



Fuel consumption was the main problem. Run time was only about two minutes. I don't know if the fuel is siphoning out of the vents or what. I don't think I had a flight that made more than about five trips around the circle.

All in all I'm happy with the way it flew. Just need to figure out where the fuel is going, and it should be good. Thumbs Up
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Re: Ordered a 1/2A Skyray kit

Post  roddie on Thu Sep 07, 2017 9:13 am

Congratulations! Glad you corrected that handle issue without incident.. affraid A piece of colored tape on the "UP" end of the handle can prevent that from happening again. I used to color-code my "UP" lead-out loop and corresponding "UP" line-connector with red paint or nail-polish to assure hooking them up properly. My handle was contoured and had a "thumb-grip".. so there was only one-way to grasp it.

Did you fly with that silicone-tubing vent-extension on the bottom tank-vent?



If so; I'm thinking that might have caused an imbalance of pressure and resultant syphoning.. but it's just a guess. Was there a plug installed in it? There was conversation regarding plugging one vent.. but I've never done that on my wedges.

Great head-on camera-shot of the model showing the wing being level.
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Re: Ordered a 1/2A Skyray kit

Post  Cribbs74 on Thu Sep 07, 2017 11:27 am

Great job at flipping the handle, not an easy thing to do on the fly. I have done it, learned to do an elevator check before model release after that.

What size is the tank?

As the prop wash goes over the vent it can/will draw fuel up the pipe, sometimes... not always. Kinda like a vacuum if you will. You can cap either vent some prefer the top and some the bottom. I personally do the top so I don't have to fiddle around the trying to cap the bottom of the tank.

Also it's common to cut your little piece of overflow fuel tubing at an angle, facing towards the prop wash so you get a little bit of pressure pushing air into the vent.

Ron
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Re: Ordered a 1/2A Skyray kit

Post  JPvelo on Thu Sep 07, 2017 1:50 pm

You might try connecting the vents with a piece of slit fuel tubing, with slit facing forward into the prop blast.
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Re: Ordered a 1/2A Skyray kit

Post  David Ingham on Thu Sep 07, 2017 5:51 pm

Good work not crashing with the handle up side down.
Checking my Baby Flight Streak with a wedge tank, it has rubbery tubes on top and bottom cut at angles to face the air stream. It is a large tank, so maybe I did lose some fuel, I was not aware of any problem. If you treat the top and bottom filler tubes differently, it might run differently when flying up side down.
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Re: Ordered a 1/2A Skyray kit

Post  TLAnderson on Thu Sep 07, 2017 9:12 pm

roddie wrote:Congratulations! Glad you corrected that handle issue without incident..


The Sig handle looks the same either way...I'll have to mark it.


affraid A piece of colored tape on the "UP" end of the handle can prevent that from happening again.

I used to color-code my "UP" lead-out loop and corresponding "UP" line-connector with red paint or nail-polish to assure hooking them up properly.




Did you fly with that silicone-tubing vent-extension on the bottom tank-vent?

Yes

If so; I'm thinking that might have caused an imbalance of pressure and resultant syphoning.. but it's just a guess.


Was there a plug installed in it?

No

There was conversation regarding plugging one vent.. but I've never done that on my wedges.

Great head-on camera-shot of the model showing the wing being level.

Thanks. Those profiles are hard to see head on. The photos are captures from a video. I watched the takeoff segment of the video in slow motion, and noticed a mist or smoke trail coming from the plane as it rose off the ground and gained altitude. Could be fuel mist coming from the tank I guess.


The tank is 3/8 oz capacity. About the same as the tank in my PT-19, which will run much longer than this one.

Some good suggestions here. I'll try some different tubing configurations, and see what works. Might be a balloon tank in the future.


Last edited by TLAnderson on Wed Jan 24, 2018 11:21 pm; edited 1 time in total
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Re: Ordered a 1/2A Skyray kit

Post  getback on Sat Sep 09, 2017 8:45 am

Good Fun !! Greenie for the Handle Flip!! LOL been there done that . plane does look to fly good , i would cap that top vent first and fly it . Popcorn
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Re: Ordered a 1/2A Skyray kit

Post  David Ingham on Fri Sep 15, 2017 2:30 pm

Does the PT 19 seem practical to fly? I have a slightly beat up red and white one with a QZ hanging on the wall. I learned on a PT 19, but my balsa trainer seemed so much better that I hadn't really thought of flying it. Does the styrene get brittle with age?
I think it is a real QZ because it has two bypass ports. It also has "Thimble Drome" on the tank.
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Re: Ordered a 1/2A Skyray kit

Post  TLAnderson on Fri Sep 15, 2017 8:07 pm

David Ingham wrote:Does the PT 19 seem practical to fly?  I have a slightly beat up red and white one with a QZ hanging on the wall.  I learned on a PT 19, but my balsa trainer seemed so much better that I hadn't really thought of flying it.  Does the styrene get brittle with age?
I think it is a real QZ because it has two bypass ports.  It also has "Thimble Drome" on the tank.

Compared to the two Testors planes I started with, the PT19 is a dream to fly. I've crashed mine pretty hard (flying over grass), and nothing major has broken, so I don't think it's brittle. It was a good one for me to use to get back into flying.



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Re: Ordered a 1/2A Skyray kit

Post  roddie on Sat Sep 16, 2017 8:37 am

David Ingham wrote:Does the PT 19 seem practical to fly?  I have a slightly beat up red and white one with a QZ hanging on the wall.  I learned on a PT 19, but my balsa trainer seemed so much better that I hadn't really thought of flying it.  Does the styrene get brittle with age?
I think it is a real QZ because it has two bypass ports.  It also has "Thimble Drome" on the tank.

David, The PT-19 is a fairly rugged model. The later one (like "TL" shows and similar to the one "I" have..) may be made of a more flexible plastic than the QZ (red & white) version.. but I can't say for sure. The wing area and span of the PT-19 is among the larger of the Cox airplanes.. making it a lot more stable of a flyer.. especially with the L/H prop that "some" came equipped with.. which was a 6"d x 2"p... (at least in later years..) I'm not sure if the "QZ" engine/version used that prop

There's little doubt that your PT-19 and its engine are an authentic example of the "Quiet Zone" version of the model. Note that the "colors" were reversed at some point.

Photos courtesy of "Travis" (CEF member WingingIt74)




Here's CEF member "Kim's" QZ-example.. which has a R/H prop installed..




The blue/yellow versions of the model originally had "tanked-engines" (Babe Bee's) and later were converted to the modular (universal) "horseshoe" backplate and an external fuel tank.. which Cox would apply to many of their models.. likely to reduce costs.

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Re: Ordered a 1/2A Skyray kit

Post  David Ingham on Sat Sep 16, 2017 3:36 pm

Here is my PT from Ebay a decade ago.

It has twin bypass ports and a 6/3 right hand screw propeller.  The one I learned on had the same open nose, was blue and yellow and had a Babe Bee, I think with a right hand 6/3 screw. It was identical except for the color and engine.
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Re: Ordered a 1/2A Skyray kit

Post  TLAnderson on Sun Oct 08, 2017 9:51 pm

Had a beautiful low wind day today, so, took the Skyray and PT19 out to fly. The Skyray flies really well. I put a 6x3 prop on it, and it jumps off the ground in about 3 feet.











Unfortunately, I'm still having fuel delivery problems with it. I don't know what's up with that wedge tank, but when it hits about half empty, that's it. The engine can not draw all the fuel out of the tank. I had several short flights. None of them made more than 5 trips around the circle.
I tried running a fuel tube from one vent to the other, as suggested above.



It didn't help. Sooo... I got this klunk tank from Cox International, and that's going to be tried next time. I ran it today with the klunk tank, and it did draw all the fuel out of the tank.
Looks a little strange, but if it works, that's ok. Oh, I managed to lose the spinner at some point in one of the flights too.

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Re: Ordered a 1/2A Skyray kit

Post  batjac on Sun Oct 08, 2017 10:56 pm

My choice would have been to go to a balloon tank.  Lighter and relatively foolproof.  If the clunk tank doesn't work out for you, try the balloon.

I stopped using the rubber spinners as I fly over grass and I lose every one I use.  Now I mostly just use the short 5-40 screws that just go on the prop with a washer.

The Lightweight Mark


Last edited by batjac on Mon Oct 09, 2017 5:52 pm; edited 1 time in total
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Re: Ordered a 1/2A Skyray kit

Post  NEW222 on Mon Oct 09, 2017 12:01 am

I second Marks advice and do a balloon tank. Easy to make, cheap to replace.
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Re: Ordered a 1/2A Skyray kit

Post  NEW222 on Mon Oct 09, 2017 12:01 am

Sorry I forgot to add. It looks very nice, as well as looking like you were having fun. Good job!
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Re: Ordered a 1/2A Skyray kit

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