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Elevator horn to E-709 alignment

CoolDadTed

Active Member
I'm working on the elevator substructure for my RV-7 and I'm having a problem with the rivet holes on my elevator horn not aligning with the holes in the E-709 rib. No matter how I try to do it, with the skin clecoed on or just standalone with the E-702 spar and E-709 rib, these holes are off by 1/16". The skin-to-substructure holes align perfectly.

I'm unsure how to proceed because anything I do to adjust the alignment of these holes will adversely affect the alignment of the skin holes.

Has anyone else had this issue? What did you do?

Here's what it looks like:

ylnye08l.jpg
 
I (and many others) had this same problem. I fixed it by adjusting the bend radius and location of the flange coming off the root rib. In particular, I moved the apex of the flange bend in such a way that allowed the root rib to nest tighter in the crotch of the bracket which ultimately got the holes to line up better, but still not perfect. Doing this had no impact on the skin to substructure alignment for me. I think I ended up ever so slightly elongating the holes in the aluminum parts while using a punch to try and align things for riveting. I'm sure its fine.
 
Thanks for the reply. I was able to do roughly what you described and I think I'll be able to rivet the horns on without too much drama when the time comes.
 
I am having the same exact issue, and I feel like I am unable to get the bend radius changed enough to get the holes to line up. My plan is to drill the holes which will result in an elongated/ovaled hole, but make a doubler for the back side of the rib. Then the ovaled holes are sandwitched between the control horn and the doubler?

Any thoughts on this? I have contacted Vans with the idea, but have not heard back in well over a week. My guess is this is a trivial problem that can be resolved without bothering the engineers at Vans:rolleyes:?
 
Just me

I would send vans an email with a picture of your best try and then call them tomorrow during the help hours. We have all been through this but it is hard to tell what is good enough with just words.
 
Definitely contact Van?s again if you have questions. They will help. It?s unusual for them to not reply for so long.
 
I had the same issue on the 10 elevator and the problem was solved by replacing the rib which Van's sent expeditiously, not the horn.
 
This was the response I got from Vans, I am going to try and get a better fit. If not, I may just order a new rib.


The alignment is worse on the right 3 holes than the left. If you look at the E-702 spar you will notice that this misalignment is created by the horn being forced downwards by a bad relationship between the spar and horn. I would suggest looking at the displacement caused by this relationship and see if you can improve this.
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If you remove the clecoes from the spar and check if you can then get better alignment for the horn/rib relationship then it may prove be wise to relieve by filing the inner radius of the horn where it bends around the spar/rib. In any case it you may have to compromise all of these holes slightly in order to get a good fit. It is worth noting that not every rivet union or hole alignment is going to be a perfect fit through the build and that at times you will need to use your best judgement and reach a logical structural compromise.
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It would have helped to assemble all the parts with clecoes up front and then finish drilling the holes. (Some clecoes might prove difficult to fit at first ? but this is homebuilding) This way all the holes would have taken up the small misalignments and you would have had a best fit scenario, rather than a situation where these are all being taken up by a few holes.
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Please revert if you do not manage to get this to fit.
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