Aileron and Flap out of alignment

[JeffPeters]

I'm wrapping up my wings and began fitting the ailerons. On my right wing, the flap and the aileron aren't forming a nice clean straight line. The trailing edges are straight when I hold a straight edge to them. Torque tube is set to neutral at the root, bellcrank alignment guide is installed, and flap is resting against the rear spar. I have the aileron inboard edge set even with the flap outboard edge. I have a pic but its kinda hard to see unless you zoom way in. Best way I can describe is the two come together like a /\. I can't say for certain how much the deviation is from the outside edges, I need to get a piece of string or something to get a definitive answer on the deviation.

For comparison I attached the flap/aileron to the left wing and it looks perfect. How significant is this what allowances can be made? I would rebuild the aileron if it is a twist but I'm not positive which one is the issue, or if its a bracket issue.

 

[N427EF]

It is kind of hard to see what exactly you are describing.
A span wise string line across the 2 surfaces would help illuminate your concern.
Right on top of the rear edge about a half inch offset would show whether or not you have a warped aileron or flap.
I don't think either of your surfaces are warped but perhaps a bit of an imperfect rear edge on either of those control surfaces.
It is hard to build a warped control surface with all pre punched parts but the rear edge can be a bit of a challenge.

 

[JeffPeters]

My exaggerated napkin illustration. I taped a fishing line from tip to tip on the trailing edge. There the two meet in, it was 1/4" off the line.

 

[lr172]

Put the string across the fwd portion. If that is straight, then the error is twist. If not, then hinges. Seems a bit odd you would have an equal amount in both surfaces and in opposite directions.

 

[Richard Connell]

It’s far more likely that your surfaces are twisted than your pivot points are misaligned.
The only way that the hinge points can be misaligned is faulty pre punched hanger and aileron hinge brackets (highly unlikely) or a twist/bend in your rear spar (even less likely)
If you place the surfaces on a flat surface it should be easy to determine if there’s twist.

 

[BobTurner]

Like the other posters, I can’t explain 1/4” vertical offset. That’s a lot. But a question: Do you have the elevator locked in neutral?

 

[Ralph Inkster]

It’s easy to check them both on a confirmed flat table. The one that wobbles is the twisted one.

 

[JeffPeters]

It’s easy to check them both on a confirmed flat table. The one that wobbles is the twisted one.

There was wobble on a table when i finished them. Even though I kept them tightly clamped through the riveting and curing process, so I'm not sure how the twist got introduced. However on the table it was "within spec" definitely less than 1/8". But I guess with them both being 1/8" off in opposite directions its now equaled 1/4".

Is this going to present an issue or is there some allowed deviation? Or do i just need to suck it up and drop the $500 for a new aileron and start there.

 

[lr172]

There was wobble on a table when i finished them. Even though I kept them tightly clamped through the riveting and curing process, so I'm not sure how the twist got introduced. However on the table it was "within spec" definitely less than 1/8". But I guess with them both being 1/8" off in opposite directions its now equaled 1/4".

Is this going to present an issue or is there some allowed deviation? Or do i just need to suck it up and drop the $500 for a new aileron and start there.

Maybe I didn't understand your drawing, but it seemed to show that both the aileron AND the flap have 1/4" of twist. Both ends should have met with the string that is 1/4" away. Did I misunderstand that? Picture seemed to confirm it.

Still think you need to get a sting on the wing trailing edge to compare and reference all of this. Otherwise just guessing as to where the line should be.

 

[Ralph Inkster]

There was wobble on a table when i finished them. Even though I kept them tightly clamped through the riveting and curing process, so I'm not sure how the twist got introduced. However on the table it was "within spec" definitely less than 1/8". But I guess with them both being 1/8" off in opposite directions its now equaled 1/4".

Is this going to present an issue or is there some allowed deviation? Or do i just need to suck it up and drop the $500 for a new aileron and start there.

Aileron, If the iron pipe/two small ribs/spar channel assy have ANY twist (not riveted completely straight) this will propagate as a twist through out the rest of the structure regardless of how forcefully it’s clamped to a straight surface.
Unfortunately, to fix it is to totally drill it back to that pipe attachment.
Flap, similar fate, unfortunately.

 

[JeffPeters]

Maybe I didn't understand your drawing, but it seemed to show that both the aileron AND the flap have 1/4" of twist. Both ends should have met with the string that is 1/4" away. Did I misunderstand that? Picture seemed to confirm it.

Still think you need to get a sting on the wing trailing edge to compare and reference all of this. Otherwise just guessing as to where the line should be.

Sorry, 1/8" comment was off - too early in the morning. The total deviation shown in the pic is correct - 1/4". The leading edges are perfectly in alignment. I pulled them back off.
Aileron laying on its top is perfectly flat.
Aileron laying on its bottom (brackets over hanging table) no measurable twist beyond a very slight flex maybe.

Flap on the other hand.. either side down, there is at least 1/4" lift at the opposite corner. Even sitting on its brackets, I can rock the opposite corners 1/4". I'm not sure how/if there is a fix to this other than rebuilding a new flap. The flap doesn't have the counterbalance pipe so that wasn't installed incorrectly.

Since finding perfectly flat surfaces and chasing my tail is a bit of a problem here, I used the method of measure wing skin trailing edge to the flap leading edge skin trailing edge and this matched up with a 3/16" delta.

 

[travisimperial]

I just finished up my right aileron and noticed a wobble on the table that I didn't recall having when I made my left aileron. Sounds like a problem for future me, but hopefully it's minor when the time comes.

 

[JeffPeters]

I've decided to build on. I figure I'll either find myself way ahead of schedule waiting for an engine and will drop the $1k then for a new flap and try again, or I'll use it as is and if it exhibits any adverse flight characteristics then I'll replace it then. Don't seen any need to rush to replace now since its easy enough to swap it out on a flying plane.