(24) Stringers ( Mike )

[planecrazzzy]

Hey Guys,
First of all.... The "Search" for stringer material was an eye opener...
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I originally wanted 1/2" X .028 6061 Aluminum round tubes for my Stringers...

It's what the Tailwind guys use...

The price of the tubing was a shock.... ACS wants $2.47 PER FOOT ( Plus Shipping )

I looked at other places and found that was about the cheapest around...

I considered other options... but some were just TOO HEAVY...

Earl's Building Pictures shows aluminum stringers that were formed in a "Brake"

Mine didn't turn out as "Rounded" as his.... But I do have a slight radius on my "V"

I Sheared strips 1-1/4" X 12 ft long of 6061-T6 .032 Aluminum

Then , Using a knife edge upper die in the Brake....

Pressed them into a "V".... Careful not to "Max out the bend , Because it

was bent "with" the grain.... and could crack....
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I formed 10 pieces... I'll have plenty of extra...

and I only used a piece 12.5" X 12'

They are very strong !!!!

Here's some pictures of the Top Stringer
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Gotta Fly...
OK... I'm at the Fabric stage... Just back here to add feedback... I do NOT like the tube on the Vertical Stabilizer...
The tube is fine... But it's TOO HIGH... The Stringer should end up the height of the Bottom of the VS...
In other words... The Tube I have here should have been about 3/8 inch LOWER...Maybe 1/2 inch...
All the other Stringers worked out fine.

[planecrazzzy]

Hey Guys,
I'm working on the side stringers now...

The Longeron area is 42"- Center to Center....

My Stringer Spacing is 14" and 14"...

The prints are a little messed up in this area... But you'll figure it out.

I used a string line to mark out the lay-out for the stringers...

There is a Mystery tube on each side...

The lower/side stringer attaches to it...

I call it a cheater tube.... It helps get around the diagonal tube

which would cause too much bend in the stringer...

Or , if the stringer was milled to clear the diagonal... it would be weak...
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I only welded it to the Vertical tube....it's plenty strong and allows flexing...

I'll cut it a little shorter later...
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Here's some pictures.... Mystery tube revealed...
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. Gotta Fly...
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[planecrazzzy]

Hey Guys,
I'm still working on the side stringers...

Here's some pictures of what I'm using to keep the stringers

lined up where I want them...

I'll put these small tubes at the ends.... and one in the middle of

each stringer area... ( Looks like the Diagonal tubes for Top & Sides )
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The Stringers will be held with Safety wire ( I'll drill holes in the Stringer Material )
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These pictures are station F-F

The supports are 6 inches apart.... Centered in F-F ( 16 inches )

I will continue the stringer further "back" than EarL's pictures...

At least the upper stringer...
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Gotta Fly...
Mike & "Jaz" the Flying Dog
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[planecrazzzy]

Hey Guys,
More Stringer supports and guides for the sides...

I can't "fit" the stringer material just yet...

I need to buy fluting pliers...

I need to use them on the end of the Stringers...

I think I can just bow the stringer material on the sides...

It'll give a nice curve... I've already tried holding it in place...

it forms good without too much pressure...
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Here's some pictures finishing up the side guides and supports...

You can see the upper stringer will come off a tube that it attached to my Rear Window Frame
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Gotta Fly...
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[planecrazzzy]

Here's a view of the "V" ...

With Calipers and a Dime to compare the size...
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Gotta Fly...

[planecrazzzy]

Hey Guys,
I got one of my side stringers done today...
Here's some pix...

This one attaches to the tube on the window frame...

I split the Stringer... and overlapped the frame

I think it'll look good with fabric.

[planecrazzzy]

Hey Guys,
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I'm working on the lower stringers, on the side...

Remember the mystery tube / Cheater tube...

As I was looking at what I was going to do...

I had the stringer stock in place...

I started looking at a way to put the stringer all the way to the door...

The Diagonal tube "Crowds" the door post...

Going around it would make a big lump....

Trimming the Stringer material would make it weak....

But.... Following the cheater tube... notching the stringer material...

I can get a better "Flow"...

"IF"... I knew I was going to do it this way...

I would have welded the tube "Slightly" inside more....

Instead of Flush with the outside... Oh well...

It'll look fine..
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Here's today's pix:
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Second picture... It's hard to see... But I put a few "Fluting" dents in the
Stringer material around the diagonal tube...

[planecrazzzy]

Hey Guys,
I'm still working on "Lining-up" the Lower Stringers...

I have Split the difference of the angle from the cabin area to the rear...

I put support posts under the front area of the seats...

I'm hoping to have a smooth transition...

Here's what I have so far...
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Gotta Fly...
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[planecrazzzy]

Hey Guys,
The transition wasn't as smooth as I wanted...

I cut the stringer supports.... and re-welded the "T"...

I like the curve/flow of the stringer in this area now...
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Compare this picture with the one above...
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Gotta Fly...
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[planecrazzzy]

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Here's a couple shots of the lower stringers in the Cabin area...
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Gotta Fly...
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[planecrazzzy]

Hey Guys,
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Wrapping up the Stringer stage....

In these pictures , At every clamp there is a small tube welded that the stringer "Straddles"
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These will help keep the stingers aliened where they are supposed to sit....

At "Final" assembly.... I'll put a small piece of "wood" , in the stringer where it

crosses and each tube... I'll be drilling small holes and safety wiring the stringers

in those spots
http://www.wingsforum.com/download/file.php?id=4690&mode=view
http://www.wingsforum.com/download/file.php?id=4689&t=1