Vertical stab skeleton oversize hole

[kens_cockpit]

I was attaching the top rib to the forward spar of the vertical stabiliser. The rivet I set bent over to the side. I decided I would drill it out and try again. The next one was no better so I drilled that one out as well! The next one was worse so I drilled that out as well. You know how the story goes but I?ve attached photos to illustrate.





My solutions:

1. Tidy up the oversize hole, debur it etc and leave it and drill another hole an appropriate distance inboard and set a good rivet. This is my preferred solution because it is relatively straight forward.
2. Drill out the hole to the appropriate size and install the next size rivet. It will be a large rivet and I don?t think I would have such a rivet to hand. That would mean I will have to source a big one and set it in the relatively thin metal. But I could probably do this.
3. Drill out the hole and install say an AN3 bolt. Extra weight and it probably looks as messy as a blank hole.
4. Create a sandwich with two pieces of aluminium on the top and bottom side of the join as per the attached diagram



It seems to me the strength in this structure comes mainly from the skin attached to the rib and spar and even a structural pulled rivet might do the trick. But can I please have your views.

I've also emailed Vans

Thanks

[lorne green]

I vote #2...oversized rivet.
Short of that go with #3... AN3 bolt. I have an extra AN3 bolt strategically attached to my airframe.

[aarvig]

Definitely number two. By the way, if practicing law doesn't pan out for you I think you would have a job waiting as an engineer! Nice drawing!

[alpinelakespilot2000]

Ken-

I made this same mistake on mine many years (it seems) ago. I think the rivet call out is a bit on the long side here causing the rivets to tip unless set perfectly. Van's response to me was to use an oversize cherrymax rivet and/or go ahead and drill a hole between the 2 original holes and rivet. I did both for good measure.

Also, and off the top of my head, I doubt you have edge distance for an AN3 bolt here on the spar flange but you should have room for a #8 screw, the latter of which is also stronger than the original rivet would have been. Wait for Van's reply though for your long-term peace of mind.

Edit: Ken-I just found this old thread of mine. See if you can relate to it? I think you will!
http://www.vansairforce.com/communit...oversized+hole

[UnPossible]

I have to admit that I am also in the club of a handful of random #8 screws and AN3 bolts..... I think it happens to the best of us

[kens_cockpit]

Now you know why drilling out imperfect rivets is pointless...
No. 1 is fine, except you can fill the hole with a rivet.
When you replace a rivet in a sllightly enlarged hole, do NOT fall for the temptation of using a longer rivet to "fill the hole." All that will happen is that the rivet will fall over sideways and be even uglier.

Thanks for the ideas. I suspect options 1 and 2 and maybe even 3 with a #8 screw would all be good but with the approval of Vans I will be going with #1and filling in the bad hole with a rivet.

Sometimes this build process seems like one step forward two steps backward. This is the second Vertical Stabiliser I am building. The first one was damaged. And I determined that this one would be perfect. Not anymore. But it will be safe and functional.

Sometimes I wonder whether I'm cut out for this but I've been doing it for years now and slowly progress is made. Preserverance. Who knows? One day it might even fly.

[ChiefPilot]

Originally Posted by lorne green

I vote #2...oversized rivet.
Short of that go with #3... AN3 bolt. I have an extra AN3 bolt strategically attached to my airframe.

An appropriate AN515 screw+washer+nut would work here as well, and wouldn't be as large of a hole as an AN3 bolt.

[aarvig]

Originally Posted by kens_cockpit

[i]And I determined that this one would be perfect. Not anymore. But it will be safe and functional.

Sometimes I wonder whether I'm cut out for this but I've been doing it for years now and slowly progress is made. Preserverance. Who knows? One day it might even fly.

Perfection is the enemy of progress. Safe and perfect do not go hand and hand. Took about 4 mistakes for me to quit trying to be perfect and just build the darn plane. Progress is made when you strive for safety and functionality. If you strive for perfection it will take much longer, cost twice as much and frustrate the heck out of you. Like my mentor said..."Aaron, you are building a tractor, not a swiss watch."

[GAHco]

Yes I am in my so many years of working on it, and like the cheese it is still getting more holes.

My advice, do your practical best, and you will get it in the sky sooner, than later.