What is the definition of hingeing?

[Paul Taylor]

I’m looking to gain a good understanding of what hingeing is exactly. When can it occur and how to identify it.

[Dave_Trible]

Paul a common example of hinging would be:  you are turning upward in the first corner of a square loop.  As you neutral on the controls the outboard wing continues forward a bit showing the bottom of the airplane to you briefly until centrifugal forces rotate it outwards again.  That wing “hinged” forward.  A common cause here below 45 degrees is too much tip weight or inversely not enough outboard flap to counter the weight.  Now continue up to the second and third corners.  Here during application of control the airplane shows either the bottom or top of itself to you.  At or above 45 degrees it is more likely flap asymmetry or one flap over or underperforming.  Here you might add a flap tab or trim the oversized flap.  This all assumes you aren’t dealing with a warp and that the airplane isn’t yawing terribly.  A bad yaw will push the inboard wing far forward into the direction of travel causing a rolling action.

Dave

Addendum:  another good way to sort the flap asymmetry issue is to do real tight and very high horizontal eights.  Watch what happens at the intersection when the control input is reversed.

[Paul Taylor]

Thanks Dave very much for your feed back.

I think trimming out a plane is the hardest part of this hobby. At least it is for me. 🥴

I am working on Nobler and the OB flap is wider than the IB flap. When doing insides it exposes the bottom and OB wing. Line tension is not lost. Same with outsides. Shows topside of OB wing.

Could it be too much OB flap?
Thanks

[Dave_Trible]

No Paul it is the opposite.  Your outboard flap needs to be larger OR inboard shorter.  Before you cut anything either pull out some tip weight or put a chunk of clay on the INBOARD leading edge at the tip (maybe 3/8 to 1/2 ounce)  and try it.  Maybe you can get a compromise that you can live with.  Otherwise glue strip of balsa on the trailing edge of the outboard flap- maybe 1/8" full span_ and go fly it.  Once you find the formula that works you can rework the flaps as necessary.  I usually end up doing this to about every other airplane I build.  Very few in my fleet have both the original flaps.  My designs usually are equal span wings with the outboard wing flap nominally 3/32" wider in chord than the inboard.  That ends up close most of the time.  What you are now seeing on your airplane is the inboard flap producing more than the outside. 

Dave

[Paul Taylor]

No Paul it is the opposite.  Your outboard flap needs to be larger OR inboard shorter.  Before you cut anything either pull out some tip weight or put a chunk of clay on the INBOARD leading edge at the tip (maybe 3/8 to 1/2 ounce)  and try it.  Maybe you can get a compromise that you can live with.  Otherwise glue strip of balsa on the trailing edge of the outboard flap- maybe 1/8" full span_ and go fly it.  Once you find the formula that works you can rework the flaps as necessary.  I usually end up doing this to about every other airplane I build.  Very few in my fleet have both the original flaps.  My designs usually are equal span wings with the outboard wing flap nominally 3/32" wider in chord than the inboard.  That ends up close most of the time.  What you are now seeing on your airplane is the inboard flap producing more than the outside. 

Dave

Again Thanks Dave for the help.
The OB flap is 2-3/4 at the root, the IB 2-1/2.
I will adjust the tip weight and maybe add clay to the IB as you suggested next outing and report back.
Then maybe add more outboard flap.
Stay tuned. 🥸

[Ken Culbertson]

Paul, this is a strange combination " When doing insides, it exposes the bottom and OB wing. Line tension is not lost".  You should not be losing line tension with an outboard roll.  You have something else at play here.  Getting the tip weight right is a higher priority than the hinging since you are going to be balancing the flap to account for whatever you have once you get it right, but it is to follow immediately. Do you have wings level in normal and inverted with enough tip weight to be comfortable overhead?

I can think of a single thing that would produce that scenario; it has to be a combination.

Ken