Heavily inspired ultralight

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patrickrio

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Aug 15, 2020
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I can’t change the calculus of the spar
I think that you are doing enough mods to the spar and wing already that you will need to recalculate the structural forces in the spar and wing anyway. Might as well make the Backyard Flyer like swing wing mod at the same time.

So you can keep the airfoil and CG the same but re design the wing, spar and attach point so that it can do swing wing when you do the structural redesign and recalc.

I forgot that the Skypup is only 2 axis for a second, so there are no ailerons in that wing. It's about as simple of a redesign and recalc as you ever would get anyway.
 
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TLAR

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Sep 29, 2020
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I am just changing the spar cap material to carbon tow same size as the wood and the slot it fits in, angled sides
The center section also relies on the trailing edge being tied to the slope with carbon fabric, uni placed on a bias
 

rotax618

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Oct 31, 2005
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Evans Head Australia
The Volmer Jensen wing was use on the Shadow and Streak Shadow aircraft, and even though the wing is cantilever, struts were used to stabilise the wing/fuselage junction under taxiing loads.
 

Gregory Perkins

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May 25, 2019
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Atlanta
The Volmer Jensen wing was use on the Shadow and Streak Shadow aircraft, and even though the wing is cantilever, struts were used to stabilise the wing/fuselage junction under taxiing loads.
Which Volmer Jensen wing are you referring to? or are you meaning similar construction or borrowing some of Volmer's design concepts ?
 

rotax618

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Oct 31, 2005
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Evans Head Australia
David Cook of CFM converted the VJ23 (I think) to the Shadow ultralight with the addition of a fuselage pod and engine. This is a photo of his powered VJ 23? experiments.

26D8B0B0-6F3C-4638-925C-3F8CF8DC082D.jpeg
 

rotax618

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Evans Head Australia
Obviously the wing construction and airfoil is a copy of Volmer’s hang glider. A friend built a Shadow many years ago, the wing design and construction is unique. From memory, the wing is 3 piece, the centre section connects the tail boom tube to the fuselage, the outer panels have a very deep lightweight D box - wood and alloy angle spar caps, blue foam and light ply shear webs, blue foam D ribs with light ply covering, the rear wing ribs are blue 19B952E0-6F0C-49FD-BA49-8B0BF02611AE.jpegfoam covered by 5 or 6oz plain weave glass cloth and epoxy. The rear ribs are bonded the the spar web with short lengths of uni glass top and bottom. ( I think the construction can be downloaded)
 
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