[jiminy]

I finished building my flaps and went to store them. After cleaning off the dust and putting them "back to back" with their trailing edges touching - the trailing edges are not straight! There is a slightly less than 1/8" gap between the two trailing edges in the middle but the tips are touching each other at the trailing edge.
A quick check of my ailerons showed the same condition.. I backriveted where I could, cosmetically they look fine (to me) with the exception of the trailing edge curve.
Is this acceptable? How did this happen? I suspect it was the work bench that may have had a 1/16" dip in the middle - is that the only cause?
If this is not acceptable - what is the remedy?

 

[jcmcdowell]

Words from my EAA tech advisor....

First- Is there a gap in the trailing edges of 1/8" OR if you put the two back to back with the flat parts next to each other there is a 1/8" gap (or 1/16" deflection per flap/aileron).

If there is a gap between skins and AEX wedge- might be a problem- 1/8" is a lot. You end up filing the AEX wedge flush with the skins anyways.

If there is a 1/16" deflection (.0625") PER aileron/flap- my EAA tech advisor would say- You might lose .0002 MPH from that- KEEP BUILDING and if you're unhappy with it AFTER FLYING, rebuild it then.

PS- I've seen some control surfaces WAY out (a lot more than 1/8" PER SURFACE) that are installed and flying with no noticeable effect.

 

[jiminy]

Curved trailing edge

Jim
Thanks very much for the reply.. The gap is at the trailing edge when I put the flat surfaces together.
I put leading edge bottom skin to leading edge bottom skin, trailing edge bottom to trailing edge bottom. Went to tie them together like that so I could hang them in my garage and noticed the 1/8" gap in the center of each surface at the trailing edge side.
It sounds like you are saying all is useable.. please confirm if you can.
thanks,
Jim

 

[Brantel]

We need pics

 

[Mark Burns]

I think I see it

Jim
Thanks very much for the reply.. The gap is at the trailing edge when I put the flat surfaces together.
I put leading edge bottom skin to leading edge bottom skin, trailing edge bottom to trailing edge bottom. Went to tie them together like that so I could hang them in my garage and noticed the 1/8" gap in the center of each surface at the trailing edge side.
It sounds like you are saying all is useable.. please confirm if you can.
thanks,
Jim

Ok,
I think I "see" what you have. Back to back you have an 1/8" gap in the center. That's just a 1/16" bow on each one. I have some like that.
I emailed Vans about it. I forget who replied but he said, "That's all the bow you have! Good job! Build on!"

Don't put them back to back anymore and it won't look nearly as bad

Mark

 

[jcmcdowell]

Yup

Ok,
I think I "see" what you have. Back to back you have an 1/8" gap in the center. That's just a 1/16" bow on each one. I have some like that.
I emailed Vans about it. I forget who replied but he said, "That's all the bow you have! Good job! Build on!"

Don't put them back to back anymore and it won't look nearly as bad

Mark

Ditto- 'build on'...

 

[jiminy]

last update

Thanks for the encourageing words.. took a closer look and noticed that the piano hinge at the leading edge is also showing the same curvature.. now the question becomes, will the fact the the piano hinge has a 1/16" bow in it lead to excessive binding in the hinge action?

 

[jcmcdowell]

nope-

they're pretty flexible.

Again- build on.

Worse comes to worse. If the hinge starts shedding eyes due to stress- drill the hinges out and install some news ones. If they're drilled to the piece in place (both sides and pin in place) the longitudial line will remain straight (i.e hinge line)

Wait till you get to the seat back hinges. The rivets can deform the piano hinge- when you the deformation you cringe with fear! The pin still fits and the hinge works just fine.