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I-strut refabrication

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Creator of this place
Staff member
Jan 1, 2006
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Austin, TX
I am planning on using the I-struts from the salvaged skybolt I have. I got all wings rigged,and then tried seeing how the I-struts looked in situ. I wasn't expecting miracles, but the differences were intriguing...as you can see in pic A, either my incidence angle was off or the orginal builder was off. Seeing this gap very rapidly coaxed me into triple checking my incidences. All was fine. The incidence differencefortopv bottom wing would have been a full 1deg on the original plane, that, or he had some sort of washout going on?

pic A

Just for peace of mind, I decided to lay out sample ribs and the I-strut to convince myself hisangle of incidences for top and bottom were out. They were out approx 3/8 - 7/16.

pic B

The next problem: As you can see by in pic C below, the box section comes up short, and is of course long the other end. This means his sweepback angle was probably nearer 7+deg rather than 6.5deg. I cannot accurately confirm my wing is the one correct [not that it matters now anyways], but I do know that I had spent days marking out the original sweep back jig [the bench] and then added concrete bags for ballast, so I feel comfortable with the accuracy.

pic C

So...I would like to try and salvage these I-strutssomehow.

1. Is there any way to safely increase the box section length in pic C?

2. I intend on heat bending the box section to reduce the gap in Pic A.

3. I am assuming trying to grind off the wholebox section to salvage the streamline tubing is maybe a non starter...
Or should i simply make new ones? [streamline tubing - $40 per ft!arrgggh]

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