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Think it'll fly?

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Thinking Think it'll fly?

Post  wha-tah-hey on Thu Oct 13, 2016 7:24 pm

Returning to 1/2A after 55+ years, I have a Skyray @ 5.8 oz dry and .012"x35' lines.
My Golden Bee peaks a 5.5x4 MA @ 14.2K, a 7x3 MA @ 10.4K on 15%.
These are the only props & fuel I have at the moment.
Would either be suitable? Cut down?
With those specs, is it likely to do anything more than roundy-rounds?
I'm hoping something at least approaching outside loops and lazy-8s.
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Thinking Re: Think it'll fly?

Post  Ken Cook on Thu Oct 13, 2016 8:55 pm

I would stay away from any 4 pitch props. That will lug the engine too much during maneuvering.  If you haven't been in the air in a long time,  a good  go to prop is a 6x3. The Skyray is pretty maneuverable when you want it to be. A 5x3 will offer very good performance over the 6x3 and typically faster. The engine is much happier when running fast but not over lean. Prop trimming is something I do a lot. You can really fine tune your performance doing so. The only real way to find out is to just try it as you might be surprised yourself.

             A 7x3 MA is out. It could be trimmed down to a 6x3 but it won't operate the same as a stock MA 6x3 due to the blade area being wider. It might work, it might not. That's a prop for a larger engine and it won't suit a .049. If your suggesting 15% nitro and a decent oil content of at least 20% your engine will be happy on that all day long.

         Loops in general are very easy on the engine as they require less demand on the engine opposed to other maneuvers. If outside loops are your thing, I wouldn't do them from the upright position. You will greatly lessen a crash if you enter the outside loop from the inverted position. The lazy 8's however are going to really taxi the engine when the plane is coming around from inverted into the outside loop. This is where the 3 pitch prop keeps the momentum driving. A 6x3 can even load the engine so dropping to a 5" is a good option.  Your plane is going uphill and it would rather pull the plane through as if it was in 2nd gear vs 3rd. Weight of model has a big impact here as well. Listen to your engine as sagging can result in rpm's.
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Thinking Re: Think it'll fly?

Post  wha-tah-hey on Thu Oct 13, 2016 9:19 pm

I have been roundy-rounding larger planes the last couple of years, with a few outside loops and wingovers thrown in (~ 70% success rate Neutral ).
I thought 1/2A may help me get over the fear (and cost) of crashing.
Better to get the most likely prop to start with, so I'll wait 'til I get a 5x3.
Thanks, Ken.
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Thinking Re: Think it'll fly?

Post  RknRusty on Thu Oct 13, 2016 11:35 pm

Although MA props seem anemic to me on larger planes, the MA 6x3 GF series are my favorite for cutting down to 5-1/4 and 5" for the 1/2A planes. I round off the tips too.

APC props work well, but you have to bush the holes with a bit of fuel tube to align them. And they break so easy it's frustrating.
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Thinking Re: Think it'll fly?

Post  Ken Cook on Fri Oct 14, 2016 4:33 am

Something that's very critical to flying 1/2A is your handle size. This was almost always overlooked by many. The end result was over controlling the plane. Seeing that most 1/2A planes have the bellcrank mounted externally, moving the pushrod to the innermost hole on the bellcrank and the furthest most hole on the control horn is a good choice if you never have flown the plane. It gives you a base to start and if more control is needed, move the pushrod wire closer to the hinge point one hole at a time on the elevator. Unfortunately, the Skyray had only one or two holes in the control horn. You still have the bellcrank option if you have limited control horn spacing. Keeping your line spacing on your handle end down to 2" limits your control making the plane easier to handle through the maneuvers without over control.
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Thinking Re: Think it'll fly?

Post  gcb on Fri Oct 14, 2016 6:38 am

wha-tah-hey wrote:I have been roundy-rounding larger planes the last couple of years, with a few outside loops and wingovers thrown in (~ 70% success rate Neutral ).
I thought 1/2A may help me get over the fear (and cost) of crashing.
Better to get the most likely prop to start with, so I'll wait 'til I get a 5x3.
Thanks, Ken.


The Skyray is an excellent plane for learning basic stunts. Make sure it is balanced well so it will turn. As already mentioned you should be at a point to set the control movement for stunt.

You may find that the lazy-8 is your friend. If you start getting dizzy, go down-wind and do some lazy-8's. You can also stretch-out the eight making it wider and wider to learn or practice flying inverted.

Some guys buy and fly old "beaters" so they don't have a lot of TLC invested in the plane. To some, this lessens the fear of crashing something you have built.

Oh, and you might want to consider a bunch of those 5x3's.  Smile

Good luck.

George
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Thinking Re: Think it'll fly?

Post  wha-tah-hey on Fri Oct 14, 2016 8:05 am

Thanks for the tips, guys.
The horn has 3-4 holes, initially set for limited movement.
I have a Sullivan 1/2A handle, spaced to match the bellcrank.
I have the balance point ~1/2" behind the LE.
Point taken on the props, George. Very Happy

BTW, what's the deal on the Points and Reputation ratings?
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Thinking Re: Think it'll fly?

Post  fredvon4 on Fri Oct 14, 2016 11:09 am

TO be totally ignored/////IMO

Bad idea from many web hosted forums

Members of places like CEF KNOW who to listen to and who to ignore

How many posts, or how many reputation points, are not good indicators of any members true value or worth

There are threads where some guy said only one thing...and that one thing was worth reading and remembering
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Thinking Re: Think it'll fly?

Post  wha-tah-hey on Fri Oct 14, 2016 11:17 am

I agree wholeheartedly, Fred, I've just never seen those on a forum before - thought it might be a CEF-specific something.
Thanks.
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