Fuel tank fit question

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JohnR
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Fuel tank fit question

Post by JohnR »

I clecoed the left tank together tonight and set it on the wing. I am planning on drilling the z-brackets using the Dan Checkoway method where you cleco on the tank and drill the end bracket then remove theleading edge anddrill theother end. Once you get both of them then remove the tank skin and drill the z-brackets.

Anyway, once I set the tank on the wing I have a gap between the tank and the front edge of the skins. I understand this is somewhat normal but it looks a little large to me. Something along the lines of 1/16 of an inch or a little more.

Before I went any further thought I would see about getting some input. Any comments on how large of a gap I should have?

Thanks,
JohnR
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cjensen
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Post by cjensen »

I think my gap was just a little less than 1/16th of an inch, but definately noticable. From the posts of others with similar problems, I just decided to press on, and not worry about it. The tank screws should pull it tight when it's installed for real.
Chad Jensen
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tshort
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Post by tshort »

I didn't really have much of a gap ...

Tip on the DC method with the z-brackets - when you have drilled them to the spar and take them off to install the nutplates, use a black cleco (can't remember which size that is) to hold the nutplate in place while you drill for the rivets. This is WAY faster than putting a bolt in each one (even if the nutplate is tapped out first)
That method for the brackets worked great for me - perfect hole placement...

Thomas
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JohnR
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Post by JohnR »

I'll probably proceed tomorrow. Sure would hate to screw this part up though. :o
JohnR
RV-7A - Fuselage - SOLD, just not supposed to be
Numbers 6:24 - The LORD bless thee, and keep thee

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TomNativeNewYorker
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Post by TomNativeNewYorker »

tshort wrote:use a black cleco (can't remember which size that is)
5/32"

Here is a cleco chart.

http://www.spenceraircraft.com/catalog/ ... /pg127.htm

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Lorin Dueck
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Post by Lorin Dueck »

John -
I'm in synch with the other posts.
Here's what I get:

Left Tank - top view (bronze cleco in tank):
Less than 1/32" -
Image

Right Tank - top view (bronze cleco in tank):
Less than 1/16"
Image

Build on!!!
Lorin D

tshort
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Post by tshort »

Just a thought ... I have not deburred the edges of my skins at all (either the wing skins or the tank / LE skins) and they fit tightly with no gap.
Any chance the deburring / filing took them down 1/32 or so each? Might account for some of the gap...

Thomas
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captain_john
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Post by captain_john »

Guys, I dunno how but, it all magically pulls together!

Relax and keep on going!

:mrgreen: CJ
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JohnR
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Looking better

Post by JohnR »

This morning I put a couple of ratchet straps on the wing and tank with a 2x4 used to clear the skin on the trailing edge and snugged them up. Much better. I now show only about 1/32 inch gap which I believe will go away with the screws. I could tighten the straps more but didn;t want to go more than just snug.

Thanks for all the replies!
JohnR
RV-7A - Fuselage - SOLD, just not supposed to be
Numbers 6:24 - The LORD bless thee, and keep thee

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jim_geo
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Post by jim_geo »

Just a thought here. I'm not so sure I'd want to be introducing stress to my construct.

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JohnR
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Post by JohnR »

Jim, I would agree 100% on that. That is why I just snugged it up. Maybe snug isn't the right word here but basically it put everything in alignment and when I took the straps off all of it stayed in place. I had seen a couple of websites that the builder had used straps in order get the tank in place. I do not believe I put any stress on anything.
JohnR
RV-7A - Fuselage - SOLD, just not supposed to be
Numbers 6:24 - The LORD bless thee, and keep thee

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jim_geo
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Post by jim_geo »

Oh I get it. You pulled it into place and when it lined up let go of the pressure and things stayed put. I'd buy that.

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Lorin Dueck
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Post by Lorin Dueck »

All -
I got to thinking. :headscratch:
Maybe I put too much Proseal on the assembly.
The skin to baffle line of rivets looked great.
But I may put too much goop under the Z brackets (even though the pop rivets seemed to set ok).
So, I'm going to go in tonight and cleco the tanks from the aft spar side - to pull the tanks down tighter.
Who knows - can't hurt...
Lorin D

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cjensen
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Post by cjensen »

Lorin Dueck wrote:All -
I got to thinking. :headscratch:
Lorin D
Shouldn't do that... :P :lol:
Chad Jensen
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Lorin Dueck
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Post by Lorin Dueck »

I KNEW someone was going to say that!!

Lorin D
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JohnR
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Post by JohnR »

:lol: :lol: :lol:

Just have to be careful what you say around here!
JohnR
RV-7A - Fuselage - SOLD, just not supposed to be
Numbers 6:24 - The LORD bless thee, and keep thee

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