Elevator root rib E-705 won't match horn WD-605-1-L

[seattleworm]

I am working on left elevator. After clecoing the skin to the skeleton, I tried to cleco the elevator horn to the spar E-702 and root rib E-705. The holes between the horn and E-702 match fine, but the holed on E-705 won't match those on the horn. Anybody had the same experience? If I drill as is, it will definitely end up with enlongated holes on E-705.

 

[gasman]

I am working on left elevator. After clecoing the skin to the skeleton, I tried to cleco the elevator horn to the spar E-702 and root rib E-705. The holes between the horn and E-702 match fine, but the holed on E-705 won't match those on the horn. Anybody had the same experience? If I drill as is, it will definitely end up with enlongated holes on E-705.

In the foto, remove the upper right cleco and install a cleco in all of the other holes...... then see how the upper right hole lines up.

 

[flion]

I don't know that kit but it's similar to the -10. Based on my experience there, here are some things to check: 1) (Mr. Obvious)Make sure there are no rivets or clecos preventing the horn fitting flush with the spar. 2) Make sure the welds have not distorted the back of the horn so it won't fit flush (one weld on my horns was a bit aggressive and had come through the material enough that it needed to be filed down to fit flush). 3) Swap the E-705s, small variances in the parts can sometimes cause them to fit better in different combinations even though they are supposed to be identical. 4) You mentioned that it didn't fit after the skins were on - does that imply that it did fit before? If so, remove the skins, install the horn, and then reinstall the skins. Now remove one cleco at a time and match-drill.

If all else fails you could ask Van's for an undrilled rib and match-drill it to fit. Alternatively, you could match drill what you have with a doubler on the other side of the rib.

 

[seattleworm]

Thanks for everyone's input. The root rib and horn fit just fine if there is no spar in the way. See picture below.

However, in the final assembled state, the spar will be between the front flange of the root rib and the horn, this will for sure offset the holes on the root rib. See picture below

I am leaning on using a doubler and drilling as is. But if all root ribs are pre-drilled like this, it looks like this should be a problem on all kits for me. (I got my empennage kit on 4/9/2011). Anybody remember seeing this?

Shawn

 

[krw5927]

There's a similar thread in the RV9 arena today.

 

[seattleworm]

Thanks, Arnie! I will try your method tonight if I can find some time. I will update my results after.

Shawn

 

[Flyfalcons]

This happened to me. The root rib lined up with the skin holes when attached to the spar, and I ended up with some elongated rivet holes where the horn attaches. Per Van's suggestion, I drilled new holes between the horn and root rib and used those for locating the horn while still riveting the stock (elongated) holes. The horn's not going anywhere now.

 

[Lemmingman]

I just looked back through my log on this and I had issues with it, as well. I describe it as

Getting the horn on was pretty routine, but did require redrilling a hole or two and jockeying with the position quite a bit.

I remember that the angle of the flange was an issue and once I bent it a hair or two the holes magically aligned and the clecos fit.

 

[Smilin' Jack]

Elevator horn

make sure that the flush rivets on E 702 spar are flush and not sticking out.

I think you have 4 flush rivets from E702 into E709.

if you have the skin clecoed on then it might help line the holes up on the flanges of the ribs and on the forward spar of the elevator. E 702 .

Smilin' Jack
Slaving on wings SB, really just got the wings

Having fun..

 

[Smilin' Jack]

One more things get all the plastic off the parts. things will fit tighter.
Mine lined up perfect like the others have said you have a pretty good space on the intersection.

 

[seattleworm]

The latest

Thanks for everyone's help here. I have bent the front flange a little more as some of you suggested, the fit is getting much better, but not perfect, there is still slight out-of-roundness in some holes. I did a quick calculation on the load on the elevator horn assuming 100 lbs pilot force on the stick (100 lbs is the FAA certification load on control stick). Based on the relative dimensions I measured off drawing 32, the maximum force on the left elevator horn is about 165 lbs (about 330 lbs total on the push rod, shared by two horns). 470AD4 rivet shear allowable is about 356 lbs each. So I deemed the out-of-round is acceptable. I final drilled the horn to the root rib. Following are some pictures.