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Fuel tank attachment to fuselage - large gap F863 to T405

kens_cockpit

Well Known Member
After many years doing other things I have returned to complete my RV8 project. I will not make any jokes about the kit being Quickbuild this being the 16th year since it was delivered to my garage. My youngest daughter has no memory of a car ever being in the garage. I am back on board now.

I have attached the wings according to the instructions and drilled the rear spar attach with the appropriate amount of incidence and sweep.

I have come to match the front fuel tank angle bracket (T405) to the fuselage front spar attach angle (F863) which I previously fabricated in accordance with the plans. It is anticipated those angles will not meet precisely because the instructions call for me to bend the F863 in the following terms:

?Adjust the main web by clamping it in a bench vise and hitting with a large hammer while protecting it with a block of wood.?

But in this case there is a large gap of about 3/8 to 13/64 between the rear face of the angle attaching to the fuselage and the fuel tank support as shown in the attached photos. I don?t think I could bend the fuselage angle as fabricated to bridge that gap while maintaining a flush fit between the facing surfaces of the angles.

Solutions seem to me to be:

1. To shim the gap ? this seems to be simplest.
2. Construct another angle to attach to the fuselage with a longer flange on the fuselage side so the edge distance can be maintained. This is relatively simple although I will need to order the angle again and have it shipped to Australia at significant cost. If solution 1 was viable and no less satisfactory I would prefer to do that.
3. Attempt a complicated multi angle bend to allow for the surfaces to meet flush. I don?t think I could achieve this successfully.
4. Persist with the instructions as per the plans and settle for the tip of the F863 to meet the web of the T405. That seems to be a weak solution which could lead to concentration of forces at the intersection of pieces.

Can I please have the wisdom of this forum about this?
https://lh3.googleusercontent.com/u...5DUeDNgwJUCK3C9VHquhKyQ5pk-UbY-g=w811-h608-no

https://lh3.googleusercontent.com/o...6MZLI_J3-koX6OQWWxZbGGrJdXF5M6fg=w811-h608-no
 
Gap

Hi Ken-
I completed this step a short time ago. Your pictures are not visible to me but if you have a gap that large, and you have made the F863's correctly, then I would venture a guess that something is positioned in a backward position. Let us know what you find.
 
something's wrong

...I completed this step a short time ago. Your pictures are not visible to me but if you have a gap that large, and you have made the F863's correctly, then I would venture a guess that something is positioned in a backward position. Let us know what you find.
Same here - just did this, and also can't see the pictures. My guess is that something is wrong, and/or you need to re-make those angles. Mine fit flush.
 
I have attached the wings according to the instructions and drilled the rear spar attach with the appropriate amount of incidence and sweep..
Is it possible the wing sweep is too much? That would certainly increase the distance between the fuel tank bracket and the fuselage front spar attach angle.

I also cannot see the pictures you?re trying to post. Here?s a link on how to post pictures from Google:

https://ctrlq.org/google/photos/
 
Vans said I should make the F863-1. That is 3/8" wider on the flange that attaches to the fuselage so it fixed the problem. Now I just have to figure out how to backdrill from the inside of the fuselage into the F863-1. it's very tight
 
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