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philr

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Dec 26, 2020
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Consider this: Each wing cell /aileron type will have its own set of mouse traps to deal with detachment/re-attachment, and storage. With the Junkers wing, you could have some pink foam insulation boards cut to slide between wing and aileron, and clamp in place, holding the aileron in a fixed position.

It is, after all, your aircraft, and your decision. I was making a suggestion.


Most likely I am the greenhorn here so this is only my perception that removing to store the wing in a trailer and reinstalling repeatedly might lead to damage since the junkers aileron isn't inline with the wing. Maybe not so.
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I haven't handled aircraft much to have a strong opinion. Ok so with your idea lets say handling removal storage is fine. How about weight and construction method? I can see it would be easier to build the wing but I don't know how to build a junkers aileron.
 

challenger_II

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Easiest way is to build a mini wing, using a round tube as spar. Hammer-out sheet metal ribs, stack on round spar. Fold a sheet metal trailing edge, and a sheet leading edge, that covers lust past the peak of the spar curve (say, three diameters of the rivets you use to attach the ribs and leading edge to the spar tube). Use AN43 bolts for the hinge points. Zenith mounts the hinge on the underside, Kitfox on the top. You can also mount the hinge point on the forward part of the spar, with a cut-out section of the leading edge sheeting.
As for the span, and chord, of the aileron, this will be based on the span, and area, of your wing panels.

As for weight, properly designed, there isn't any reason a Junkers wing cell should weigh more than a conventional cell.
 

philr

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Easiest way is to build a mini wing, using a round tube as spar. Hammer-out sheet metal ribs, stack on round spar. Fold a sheet metal trailing edge, and a sheet leading edge, that covers lust past the peak of the spar curve (say, three diameters of the rivets you use to attach the ribs and leading edge to the spar tube). Use AN43 bolts for the hinge points. Zenith mounts the hinge on the underside, Kitfox on the top. You can also mount the hinge point on the forward part of the spar, with a cut-out section of the leading edge sheeting.
As for the span, and chord, of the aileron, this will be based on the span, and area, of your wing panels.

As for weight, properly designed, there isn't any reason a Junkers wing cell should weigh more than a conventional cell.
ok another question I see kitfox and Zenith both have lifting airfoils is that the most common? Also don't see many junkers aileron only mostly full span flaperons.
1624398829664.png
 

philr

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Dec 26, 2020
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64
That would be the Junkers ailerons. In some documents, they are listed as Junkers flaps.
I drafted a version with junkers ailerons. The weight comparison is ridiculously close within a tenth of a pound. Can we shorten the wingspan due to the extra lift from this setup. Size of the aileron is 82" x 12".
RIBLETT 30_615 MODEL junkers.jpg
 

TLAR

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Pylon500
What is the dia and wall of that tube please if you have the numbers laying around
 

challenger_II

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You can shorten the span, yes. However, as the Junkers aileron counts as chord, I would reduce the main plane chord such that the chord of the "Junkers Wing Cell" was the same as the chord as originally designed. This way, you do not shift your center of pressure, and CG, aft. I would, however, maintain the same thickness of the main plan. This, of course, does change your airfoil somewhat.

As for your diagram of the airfoil, with Junkers aileron, make your spar tube diameter such that the rib flanges fit the OD of the tube. This way, you are riveting the rib flange directly to the spar tube. Allows for a larger spar tube, and cuts down on fiddly bits to connect the rib to the spar. If you cut down on parts count, you will, generally, cut down on weight.
 

philr

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Dec 26, 2020
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64
You can shorten the span, yes. However, as the Junkers aileron counts as chord, I would reduce the main plane chord such that the chord of the "Junkers Wing Cell" was the same as the chord as originally designed. This way, you do not shift your center of pressure, and CG, aft. I would, however, maintain the same thickness of the main plan. This, of course, does change your airfoil somewhat.

As for your diagram of the airfoil, with Junkers aileron, make your spar tube diameter such that the rib flanges fit the OD of the tube. This way, you are riveting the rib flange directly to the spar tube. Allows for a larger spar tube, and cuts down on fiddly bits to connect the rib to the spar. If you cut down on parts count, you will, generally, cut down on weight.
This brings up the CG location... before going much further I need to refine the weights of everything and tweak the fuse if needed but now if we change the wing again weights will change. If I shorten the chord then do we need full span ailerons? I can take the same airfoil but 18% thick. With a main wing chord of 45 18% thick is 8.1" max thickness.
 
Last edited:

pylon500

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Taree Airport Australia
Pylon500
What is the dia and wall of that tube please if you have the numbers laying around
Oops, I see things have run on while I was away...
Where I was mentioning a tube for the aileron, I was looking at your first idea for the aileron being a round leading edge inside a concave rear spar, or knuckle style I think it's called. This is typical of the Team/Ison aircraft (wood), but I'm not sure how they're done.
My thought was to use whatever diameter you drew (looks like ~2"?), then rivet ribs and a trailing edge behind it then cover it. The tricky bit being how to pivot it?
You could probably find 2"ø tube down to about 0.035" wall from the hang glider people (Just looked at Spruce; 1 3/4"ø or 2 1/2"ø x0.035" wall in 6061-T6).
I've mixed feelings about the Junkers style, it looks basic, but to make it work well can take a bit of experimenting (or careful copying), and is in the long run probably a little more complex to make than barn door ailerons, and a bit more draggy, depending on your final operating speed.
I mentioned earlier about Piper Cub style frieze ailerons, and point out that the sharp leading edge used there is to combat adverse yaw caused by the fact that as a closed loop cable system, there is no differential available, so without the fairly strong drag of the aileron leading edge, the yaw would be quite noticeable. However, the yaw is being beaten by adding lots of drag... 🤔
If you can get differential into the aileron movement, then you can round the leading edge and get less drag when it's up, and better flow over it when it is down.
 

philr

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Dec 26, 2020
Messages
64
Oops, I see things have run on while I was away...
Where I was mentioning a tube for the aileron, I was looking at your first idea for the aileron being a round leading edge inside a concave rear spar, or knuckle style I think it's called. This is typical of the Team/Ison aircraft (wood), but I'm not sure how they're done.
My thought was to use whatever diameter you drew (looks like ~2"?), then rivet ribs and a trailing edge behind it then cover it. The tricky bit being how to pivot it?
You could probably find 2"ø tube down to about 0.035" wall from the hang glider people (Just looked at Spruce; 1 3/4"ø or 2 1/2"ø x0.035" wall in 6061-T6).
I've mixed feelings about the Junkers style, it looks basic, but to make it work well can take a bit of experimenting (or careful copying), and is in the long run probably a little more complex to make than barn door ailerons, and a bit more draggy, depending on your final operating speed.
I mentioned earlier about Piper Cub style frieze ailerons, and point out that the sharp leading edge used there is to combat adverse yaw caused by the fact that as a closed loop cable system, there is no differential available, so without the fairly strong drag of the aileron leading edge, the yaw would be quite noticeable. However, the yaw is being beaten by adding lots of drag... 🤔
If you can get differential into the aileron movement, then you can round the leading edge and get less drag when it's up, and better flow over it when it is down.
The radius drawn there is 1.75" I planned on using .016 aluminum bent there. It would need 3.5" tube and seems heavy how about making a D tube there?
 

challenger_II

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327
Location
Fisher County, Tx. USA
There is a whole range of information, regarding efficiencies of long, narrow wings (greater span loading), vs short, wide wings, Drag is greater on the short wide wing cells.
Ultralight aircraft are notorious for having less than great aileron authority, due to our low speed rates. I wouldn't short myself on aileron area.


This brings up the CG location... before going much further I need to refine the weights of everything and tweak the fuse if needed but now if we change the wing again weights will change. If I shorten the chord then do we need full span ailerons? I can take the same airfoil but 18% thick. With a main wing chord of 45 18% thick is 8.1" max thickness.
 

poormansairforce

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Mar 28, 2017
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Just an Ohioan
The Mini Max way is really simple. It's just a short metal sleeve bushing cut from 1/4" tubing that is held on to the nose ribs at 3 locations with a bolt. The end bushings slip into holes in the outside brackets and the center bracket is slotted to accept the center bushing. By removing the wingtip bracket you can take the aileron off.
 

philr

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Dec 26, 2020
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64
The Mini Max way is really simple. It's just a short metal sleeve bushing cut from 1/4" tubing that is held on to the nose ribs at 3 locations with a bolt. The end bushings slip into holes in the outside brackets and the center bracket is slotted to accept the center bushing. By removing the wingtip bracket you can take the aileron off.
Other plans I am looking at for lots of these details is how the Legal Eagle is made and then adapting that to metal versus wood construction. A lot of what Milholland designed looks like it came from the minimax but there is a level of simplicity and cutting everything down to "Only what is necessary" that I think is really the way to go.
 

philr

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Dec 26, 2020
Messages
64
I have decided to move forward with ailerons in the wing and controlled through a torque tube. Here are my plans with the updates. HERO PLANS
 
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