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Wing skin doubler - do I have an issue

PostPosted: Sat Jul 18, 2015 1:02 pm
by Sonex1542
On the left wing I missed the note about riveting the skin doubler until after fit up of wings and is riveted in. I then noticed the note and removed the root rib. So I'm looking at this with panic since there are oh so many rivets.

What if anything am I up against? There is mention about trimming the lower strap of the doubler, but am hoping I'm an exception.

Thanks.

Re: Wing skin doubler - do I have an issue

PostPosted: Sat Jul 18, 2015 6:31 pm
by sonex892
Sorry 1542 if we are talking about the same thing? I think you do have an issue. The doubler is normally trimmed to suit the gap for the rubber trim with the wings fitted. After the wings are rigged.

Steve 892

Re: Wing skin doubler - do I have an issue

PostPosted: Sun Jul 19, 2015 12:07 am
by Sonex1542
Can others also weigh in on this. The skin doubler is the piece you walk on. Is it possible to rig the wings and trim on the fly. It's not that I'm lazy about removing rivets... But really, if I can, and its possible to rig them. I also feel that replacing this many rivets in a high stress area is introducing more risk that other options.
I do want to mention that all the sheet is factory if that makes a difference.

Gonna need to go over the rigging process and see about the rubber trim and how it comes into play. So disappointed in myself.

Re: Wing skin doubler - do I have an issue

PostPosted: Sun Jul 19, 2015 12:29 am
by Gripdana
You might be able to rig the wings with it on. But you may have to remove the left wing to trim enough material so the doubler does not interfere with alignment. It is not all that bad to remove the rivets and take off the doubler. Just be careful when drilling them out. I think to take the doubler off will make it easier to rig the wings. If you would like to give me a call PM me and I'll send you my phone number if you don't have it. If you use Vans wing root rubber the amount of trimming will be greater than called out in the plans.

Re: Wing skin doubler - do I have an issue

PostPosted: Sun Jul 19, 2015 7:11 am
by peter anson
I'll back Dana on this. Drilling out rivets is not that bad. Guess how I know. If you decide to drill the head off and punch the tail through, use some sort of bucking bar to support the rib flange close to the rivet tail. You might notice that it's a three-handed job though. If you do happen to enlarge a hole, Spruce (or just about any aircraft supplier) can sell you oversize Cherry-max rivets. Don't beat yourself up about making a mistake. The only way to never make a mistake is to never do anything in the first place.

Peter Anson
Sonex 894
198 hours

Re: Wing skin doubler - do I have an issue

PostPosted: Sun Jul 19, 2015 8:23 am
by Gripdana
When you are ready to rig the wings. I have the drill bit called out in the plans. If you would like to borrow it just let me know.

Re: Wing skin doubler - do I have an issue

PostPosted: Sun Jul 19, 2015 8:33 am
by DCASonex
Also back Dana. Best not to mess up with that many rivets. Too much chance for Murphy's law. You may have to remove and install wing a couple of times as you trim it down, but still easier and safer than removing the doubler. I have the Van's rubber wing root seals on mine, they add a nice touch, but also a small amount of weight.

David A.

Re: Wing skin doubler - do I have an issue

PostPosted: Sun Jul 19, 2015 8:34 am
by Rynoth
Sonex1542 wrote:On the left wing I missed the note about riveting the skin doubler until after fit up of wings and is riveted in. I then noticed the note and removed the root rib.


Why did you remove the root rib?

My doublers needed almost exactly 1/4" of material removed on each wing. I would imagine if you removed a little more, say 3/8" or 1/2", you may have sufficient clearance to rig the wings, and just a slightly larger gap to fill later.

The below pics show how much I removed (ended up being the same on both sides) and the close gap after installation.

Image

Image

Re: Wing skin doubler - do I have an issue

PostPosted: Tue Jul 21, 2015 3:29 pm
by Sonex1542
Ryan,

The root rib was just floating in place. Cleco'd in really, so it wasn't anything I should have added to the question.

As Dana, David and you maybe eluding to.. Is that I can (maybe) see what happens on the wing fit up and give it a few goes at guessing (an educated based on your comment) of how much to remove. I'm thinking... I should pickup the rubber casket that goes in between the fuse and wing to judge better on the fit to expect then?

Based on what I read on wing rigging Is that the three 1/4" holes will be where I want to get to and pretty much it locks in from there? So, if I can get to that point on a few attempts, it's going to be working backwards then on the proper gap between the doubler and the side of the fuse for the gasket?

If I'm thinking this through correctly, I'm really not in a complete pickle, and can work through this, just will take a few attempts at getting the wings in he right spot? Right? (Fingers crossed)! And it's only the left wing so half a pickle :D

Let me ask this... How much of a tolerance would you say I have for the gasket +/- 1/8 ?

Re: Wing skin doubler - do I have an issue

PostPosted: Tue Jul 21, 2015 4:10 pm
by Rynoth
I can't answer your question on the gasket width (I don't have any yet), but I think your reasoning is sound for the fitting of the wings. If you are able to safely support both wings as you slide them into the spar tunnel, eventually the root doublers will contact the fuselage side panels before you can get the spars fully mated. You could then guesstimate/measure the additional clearance needed in order to mate the alignment holes. Then cut back each of the doublers by 1/2 that amount + extra for clearance and to give you room to tweak the wing position during the rigging. Properly done it probably wouldn't take all that long.