incorrect rib used

[Reilly]

Hi. I need some advice from the experienced builders please. Despite being carefull to get all my wing ribs in the correct order and places, it seems that i have made two mistakes.

Firstly on the right wing, I have main ribs 5 and six from the outboard side switched. This is not the one with the hinge bracket. The only difference is that six is aft trimmed and five is not. The ribs are otherwise the same.
I picked this up when riveting the ribs to the spar. Is it important to drill out and switch or can I leave them?

At this point I decided to check the right wing nose ribs and discovered another mistake. I had a W 1208R nose rib that was not aft trimmed. I checked the left wing and discovered that I had used the fwd and aft trimmed rib in step 3 on page 15-05 instead of only a fwd trimmed rib. This is the second rib on the inboard side. ie one where you would walk on the wing.
So it is only riveted to the attach angle where it should be riveted to the angle and spar.

As I have riveted all ribs and spars it would be a mission to undo. So I need to know if it is necessary to drill them all out (and those necessary to get to these) or does the wing have more than sufficient strength as it is?

All responses would be appreciated.

 

[Mich48041]

Only an engineer can answer your question.
My father always told me, "Do what you do, do well, boy."
When faced with a problem like this, I ask myself, "What is best in the long run?", and do that, rather than doing what is easiest at the moment. Just think how much easier it will be drilling out those rivets now before the wing skin is riveted in place. In fact, the wing skin holes might not line up if ribs are in the wrong position. Some day when you are flying in turbulence and getting slammed into the seat, you will be thankful that you built the plane according to plans and not have to worry about the strength of the wing.
Sometimes it is easier to just go ahead and do it the hard way to start with.
I know that this is not what you wanted to hear. It is going to take time to fix mistakes, time that could be spent making progress. I figure that it took me 4 times as long to build my RV-12 as it should have. One time to build it the wrong way, two times to take it apart, and one more time to build it the right way.
Joe Gores

 

[DHeal]

What Joe said. If you don't correct it, it will always be on your mind. Redoing such things is part of the journey! -- David

 

[Dave12]

When you make your first and subsequent flights you will have enough on your mind without wondering about the integrity of your work. It is one thing if something is awry and you don't realize it. It is another if you know it. There is only one answer. Always listen to Joe!

 

[MartySantic]

Agree with all. It is SO easy to drill out the rivets and correct anything amiss! If you have not tried to drill them out, practice on some scrap. It is SO easy! Been there.

 

[N282S]

Really think about it.

Hi Reilly,
I'm not sure how things will look and fit once the wing is skinned AND painted. One of my big mistakes was not to carefully ensure that each rib flange was squared at 90 degrees. Once the wing was painted every little bump and dip along the rib rivet line was very noticeable. So, with a misplaced rib, I'm not sure how smooth and flush the top of the wing will look once painted.

I know it's a pain and South Africa is a long way from the warehouse in Oregon, but, I think the next three things I would grab is the drill, the credit card and the cell phone.

Good Luck. ymmv.

 

[Reilly]

Thanks

Thanks for all the responses. Sanity prevails and I have started to drill the rivets out.

Lots of practice ahead

 

[paul330]

I'm building a -10, not a -12.

However, I guess a lot of things are similar and structural issues still apply. Ribs are left/right handed and some are modified to provide clearance for various reasons. If you have managed to get ribs in the wrong place then, in my opinion, you have no choice but to sort it out - which is what you seem to have decided.

'nuff said.

Only 2 months to my next holiday in SA

 

[Reilly]

Fixed

Response from Vans was the same. rather drill them out. I had also found that I attached all the left wing main ribs to the outboard side of the attach angles instead of the inboard side.

Funny that the plans state that the nose ribs must be attached to the outboard side but do not make this statement when you attach the main ribs which are done first. With hindsight you can pick it up from the picture but here my inexperience counted against me.

So now I facedhaving to drill out over 100 rivets

Rudi Greyling loaned me his angle drill which I needed for some and armed with my pneumatic drill and a new drill bit it took me a good 5 hours to get them all drilled out and re-riveted.

It got easier as I gained in experience. I damaged one hole on one rib (This was before I had the angle drill and needed it here) So one rib on order from Vans and I am back on track.

Thanks for the advice.