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Gentle Lady Removable Wingtips Option

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Old 10-10-2012, 06:32 AM
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Nikolas K
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Default Gentle Lady Removable Wingtips Option

Hi all!

For the Gentle Lady sailplane, we have the option to go for a wing with removable wingtips. The instructions clearly show how to do it, but each wing panel uses just one brass tube in the forward spar, apparently for weight saving.

Having read the Electra and Sophisticated Lady instructions, I have seen that they also use a brass tube in the rear spar for each wing panel. In that way, the outer wing panels cannot rotate relative to the inner wing panels and the outer wing panel incident does not depend solely in the electric tape that you will use.

The question is, should I follow Electra and sophisticated lady way to make wingtips removable, or just do what the Gentle Lady's instruction say?

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Old 10-11-2012, 07:24 AM
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Default RE: Gentle Lady Removable Wingtips Option

Anyone?

Mods, should this thread be removed to a more relevant forum, eg "Kit Building"??? I receive no answers here...
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Old 10-11-2012, 07:35 AM
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Default RE: Gentle Lady Removable Wingtips Option

I have a Gentle Lady, and went with the removable wing tip option. The electrical tape works just fine to hold the trailing edge of the wing. But, if you are going to convert it to electric or use ballast then you may want to add a rear spar joiner to be safe.
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Old 10-11-2012, 08:04 AM
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Default RE: Gentle Lady Removable Wingtips Option

At the very least I'd use a short stubby alignment pin at the rear spar. I'm not the sort that likes to depend on tape for alignment. But if it were me I'd go with two joiner rods since there are two spars.
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Old 10-11-2012, 10:09 AM
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Default RE: Gentle Lady Removable Wingtips Option

Thanks for the answers. I wanted to learn what other people have done. I am going definitely with two joiners for many reasons. It will be electric and I also like to have the outer panel aligned with something more rigid than a tape. Moreover, I cannot see how It is possible to give the washout with only a tape holding the outer panel.
I will post photos of the removable panels construction here, just because I couldn't find any in the forum.
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Old 10-11-2012, 10:24 AM
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Default RE: Gentle Lady Removable Wingtips Option

I made my electric Gentle Lady with the removal wing tip option and did what BMATHEWS describes, the music wire into tube spar extension, small dowel aligning pins all held together with elecric tape. Never had an issue, had heaps of flights now.

Wash out is not a problem, just build it into the wing tips.

Make it as per the instructions, with small aligning pins, all good.

Remember weight is an enemy to model planes
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Old 10-11-2012, 10:52 AM
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Default RE: Gentle Lady Removable Wingtips Option

Two alignment rods are proven from years and years of use.

The stabilators on lots of gliders often were two different size piano wire rods, one where the rotation was and one where the stab's AOA was controlled. The heavier one was not only the hinge but was also more than strong enough to carry the stab load. Now..... why go into all this? because.....

The two stabilator halves were held on the airplane by the smaller, aft rod. Nobody usually liked the idea until they did it. First time I saw it was a Sagitta kit. (also the first stabilator design I saw) I didn't like it. Why? Because you simply kinked the wire rod and relied on the kink to hold the two halves together. I glued one side just because. The kink is just enough to bind the wire rod in the tube but not so much the wire won't go in. It works like gangbusters. That Sagitta 600 is hanging in the shop right now. If I had a flying site large enough for a highstart, that Sagitta would be flying right now.

Would I hold a wing together like that? Nah. Not a 2 piece wing. But I've seen a 3 piece wing with the outer panels held on that way.

For the smaller pin, if you're going to use piano wire or CF rod, the smallest you can handle will be way more than strong enough.
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Old 10-12-2012, 07:35 AM
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Default RE: Gentle Lady Removable Wingtips Option


Quote:
ORIGINAL: da Rock


For the smaller pin, if you're going to use piano wire or CF rod, the smallest you can handle will be way more than strong enough.
That's what I will do. I have a smalle gauge wire and I will use it. I will post photos.
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Old 10-12-2012, 11:20 AM
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Default RE: Gentle Lady Removable Wingtips Option

Even with dual load bearing wing rods I would still use a layer of tape to join the panels. The reason being that it holds the tips from slipping outward and the tape also will form an airseal so the air won't leak from the lower to top side. Letting the air leak like that produces a heap of drag and lost lift.
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Old 10-13-2012, 06:07 AM
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Default RE: Gentle Lady Removable Wingtips Option

Quote:
ORIGINAL: BMatthews

Even with dual load bearing wing rods I would still use a layer of tape to join the panels. The reason being that it holds the tips from slipping outward and the tape also will form an airseal so the air won't leak from the lower to top side. Letting the air leak like that produces a heap of drag and lost lift.

Yeap, definitely with tape. Even full size planes, for example Pipistrel Sinus with removable wingtips, urge you to tape the gap:
http://www.pipistrel-usa.com/manuals...tips-Sinus.pdf
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