W

Wills_9A

Active Member
I am not overly concerned with this, but I was wondering if this ripple looks normal to anyone else here. I have it both of my leading edges and can only really be seen in certain lighting conditions. These were assembled in a jig with no pressure being applied to the skins so I am stumped as how this happened and whether I should even care...suggestions?

View the ripple
 
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Hello Wills

I'm at the same stage on my RV-7 Wings, and it look the same! First I tried to better fluting and bending the flange of the ribs, but they where ok. So it looks that it must be like this. (the noseradius of the skin is a little to smal pre-bent, so that the skin have the smaler radius between the ribs, and at the ribs the skin is pressed to the outside a bit) First I was concernd about this, but i think a few thousend RV's are flying like this, so it must be ok. Maybe somone else can confirm this (how does it look on QB's?)

Dominik
Wings
www.myrv7.ch
 
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Will,
I had em too on my 9. I just worked them out with a small plastic hammer a little at a time.
Frank K
90989 Fuse
 
I can't tell without looking at a better picture but these look like the typical things that come from the very tip of the nose ribs, where the flange at the bends seems to be slightly above where it should be. I think I was warned about these (as I recall it was something like "you can always tell an RV, they've got the ripples at the leading edge). When I fitted my LE skins, I had these. I took the skin off and tried used the Scotchbrite wheel along the web/flange intersection to try to smooth it a bit, but I'm not sure I succeeded. I decided not to worry about it.
 
Another point to make is that, if I'm seeing the photos correctly, the ripples result in ridges that are longitudinally oriented with the direction of flight, i.e., with the rib edges.
That should have no measureable effect on airfoil performance.

Now, if a ridge were to be on the leading edge that ran along the leading edge, thereby breaking up (changing) the airfoil shape, then you'd have a huge problem.
 
Thanks to all,

yeah these only run longitudinally at the rib points. I plan on trying some very light tapping with the rubber mallet when done, otherwise I am going to forget about them...thanks again for the info. Glad to hear this is a common problem.
 
I'd be careful about trying to bang 'em out. Maybe it'll work, but maybe the ribs will act as a dimple die too. In fact, I can almos guarantee that will happen. You've got a thin aluminum skin and a thicker aluminum rib. It won't be the rib that changes shape.
 
I don't recall this ripple occurring on my wings, but mine is an older kit. I think the best thing to do would be to send an email with the photo to Van's. They always get back to me within 24 hours and have seen it all.

Steve Zicree
 
I would also be careful about banging them out.

Going back to the airflow issue; I would much rather have a clean longitudinal ridge in that area rather than a bunch of dents that could disrupt airflow.

That ridge doesn't really change the airfoil shape (in profile) at all, while a series of small dents can have a huge effect. Especially in the leading edge area, don't think of dents as dents, think of them as "disruptors". :eek:
 
No need to bang them out!!!! An interesting little thing happened after deburring, dimpling and riveting....the ripple went away (or is damn near unnoticable in some areas). I could not believe it myself, but could not be happier to see it go. Thanks again for all of the information and advice!

Now with no ripples
 
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Ahhhh... I see. I thought it'd already been riveted, dimpled etc. Yeah, funny how that tightens things up. I've had pieces that I could swear were going to "oilcan" and once riveted they were tight as a drum.


BC
 
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