Flap/Aileron Training Edge Alignment

[sonex1678]

Sonex and Waiex folks:

After getting my first wing together, except for final riveting, I checked the flap/aileron trailing edge alignment at the neutral position (such as with flaps up, ailerons neutral) and found that the aileron trailing edge is further forward than that of the flap. I rechecked the hinge installation and both were correct. Stumped, I then checked the flap/aileron skin sizes per SNX-Z02 (my skins are factory cut and bent) and see that the aileron is about 3/16" shorter than the flap, which would make the trailing edges not align at neutral if the hinges are installed exactly per the plans. As a result, I replaced/redrilled the aileron hinge to move it rearward a little so that the aileron trailing edge would match the flap at neutral (I couldn't move the flap hinge forward since it would start to limit the flap's upper movement and might stop the flap from reaching neutral). After doing this, the trailing edges align at the neutral position; however, the upper hinge extends further back exposing more of the hinge "lugs". Sonex Tech Support indicated that it was OK to move the hinge as long as only the hinge lugs were exposed (good news) but also thought the misalignment was unusual--they checked one of their aircraft and the misalignment was less than 1/16", whereas mine was more like 3/16" (which is what my calculation indicated it would be), so I have some concern. Of course, without seeing exactly where the factory hinges are actually located, the fact theirs aligned better might just indicate that the hinges were initially drilled more like my second setup....

So to all of you who have already passed this point in their build..., am I missing something and the misalignment I had was really "unusual", or have others experienced the same thing? I tried to look at various acft photos and builder logs, but it was hard to tell what other experienced as most of the photos have the flaps down...). Also, if others have experienced the same thing, did you just leave it as is or did you go to the trouble to move the hinges somewhat to get the "perfect" alignment at neutral? It is great that everything now lines up at neutral on my wing, but the exposed hinge lugs aren't quite as attractive, and I want to be sure I am "not missing something" before finishing this wing and beginning the next....

Any and all assistance and comments will be greatly appreciated.

Doug

[Rynoth]

Do you have any pictures? Honestly, my first thought is that you put the hinge on the wrong edge of the aileron, but it should be fairly obvious that the hinge goes on edge where the skin overlaps.

When you say you checked the skin sizes per SNX-Z02, are you saying that the skin width provided in your kit doesn't match the depicted plan width?

[tonyr]

G'day Doug,

This is a bit like the " help one is hanging lower than the other" concerns... when you're sitting in the cockpit flying the across the wide blue yonder you will never notice your aileron is slightly further in than your flap!

In fact if you're really having fun flying it, they will rarely be in the same alignment ever

All fun aside..

You might find when you actually rig the ailerons and flaps on the wing they are closer together than you think they otherwise would be. I was about to do some of the things you have done with the aileron hinge but I held off. When I finally assembled and rigged everything, there was about an 1/8" difference, and also the gap between the aileron edge and flap edge was a little wider on one side than I liked.

To frustrate those grumpy flight line scrutineers lurking at flyins and airshows from focusing and commenting on it, I always park with flaps down.. that way they never see it and I rarely think about it anymore.. (and it doesn't show up in photos..lol)

Good luck with your project..

Cheers
Tony

[tonyr]

Q. Which aileron is further in than the flap?



A. actually both

[sonex1678]

Sorry for the delay--had to get a few more photos, which meant some clean up, wing flip, and basic re-level (and relearning how to post photos via links). First photo shows wing up side down with flap hinge centered on wing trailing edge (wing squared/leveled and all skins cleco'd). Second photo shows misalignment of flap/aileron when both at neutral position (aileron hinge also centered on wing trailing edge). Third photo (today) shows wing right side up, re-leveled (quickly). Fourth photo shows better flap/aileron alignment after moving aileron hinge back somewhat. Fifth photo shows how far back aileron hinge is now, which isn't as appealing as more hidden hinge, but alignment is better. Need inputs before I finish wing and go on to next since the two wings need to match. Bit sure if I should move aileron hinge back to original location (centered on wing trailing edge) or make second wing like this one. My biggest concern is being sure it is safe with the hinge moved, which Sonex indicates it is, but might be better where it was. As a side note, the relocated hinge has the rivets located pretty close to the exact center of the mail part of the hinge body (not including the lugs) whereas the "correctly" installed hinges are actually riveted closer to the lugs..... Also, as I mentioned, on SNX-Z02, the length of the flap is actually longer than the length of the aileron (leading edge to trailing edge), so at neutral some misalignment would pretty much be expected unless the hinges were drilled with the two controls aligned during drilling....

Thanks,

Doug

[sonex1678]

Tonyr:

Your's look pretty good in the photo--took a look at your website and in a few photos can see some very slight difference, but looks like you got a lot closer than I did originally...did you drill the hinges exactly with both hinge lugs centered on the wing trailing edge or did you do a little "eyeball" alignment with bot flap and aileron in place when drilling hinges?

[Rynoth]

So I just went back and found this pic on my blog from 2 years ago when I just finished my flap/ailerons. It didn't bother me then and doesn't bother me now, and doesn't seem much different than what you have.



Aileron is on the right, and probably about 1/8 to 3/16 short the flap at neutral deflection.

[sonex1678]

Rynoth:

Looks almost exactly what I had before moving the hinge. And have again re-looked at SNX-Z02 and aileron is definitely cut shorter than flap per the plans (flap 13 7/16 vs. aileron 13 17/64), so guess it is what is expected. Probably wasn't worth the effort to move the hinge so they look aligned--now someone will point out that the hinge isn't center on the wing trailing edge instead of noticing that the surfaces aren't aligned perfectly--just can't win....

[peter anson]

You may be worrying about nothing. Because the flap and aileron hinge on different axes, there is only one spot where the ends line up. At every other angle they will mismatch. I can recall thinking I had a problem when I first fitted the flaps and ailerons, but once everything was rigged it all looked fine. That said, in your first photo, the hinge appears to be set a bit too high. Have you allowed for the skin thickness when you located the aileron hinge?

Peter
Sonex 894
240 hours

[sonex1678]

Thanks all--seems like what I thought might have been a problem is actually correct (Sonex could fix by changing either the flap or aileron size slightly to match, but I guess its not really worth the time/expense since it is really only cosmetic). I had considered drilling out the repositioned hinge half and putting back the original so the hinge lug was centered on the wing trailing edge, but think I"ll probably leave as-is (drilling out the entire hinge might be risky) and similarly adjust other wing during construction. Added benefit is that the hinge is actually now drilled 1/4" in from the edge of the main hinge body vice 1/4' in from the center of the lug, which is what EAA recommends in their drilling video (which actually "uses" the Sonex as an example).

So now my single point where the flaps and ailerons line up are at the neutral position so I won't get comments about misalignment, but the whole lug shows so I'm sure I'll hear about that from someone. Guess I should have just left things alone and parked with the flaps extended in the first place :)

Thanks everyone--and ALL your acft look GREAT--hope to be there someday too.