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These two pieces of metal are .063 thick material that I previously annealed. I want these
to nest in the 3/32" radius of the rib, which will require me to use a much smaller bend
radius than possible with -T3 temper. In the -O temper, I should be able to use a bend
radius that is as small as 1x the material thickness.
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Hrm...in preparation for bending those doublers, I tested on a couple samples. This material
is .063 thick and I used a 1/16" bend radius. On the top part, the grain direction is parallel
to the bend and resulted in a crack. On the bottom part, the grain direction is perpendicular
to the bend and did not crack. I'm uncertain if this is because my temperature control was
a (suspected) problem when I annealed the sheet, or if it's solely due to the grain direction.
Since it's going to be a little while before I can get the oven issues sorted out, I'll order
some -O material. Also, I may order some thinner material since .063 seems a bit too thick
for these doublers. Van's design doesn't use any doublers at all. Yes, my design will
experience ~25% greater load, but even without any doubler, the fact that I have two full ribs
to support the pivot (instead of one full rib and one half rib) should already be sufficient.
I'll still add a doubler, but I'll probably shoot for .040 or .050 thick instead of .063.
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So, I went looking for these bolts in order to modify them, but couldn't find them after
maybe an hour of looking. I hate doing this, but decided to just order a couple replacements.
Checked Aircraft Spruce...they want $20 EACH for these. Guess who didn't order replacements.
I'm going to have to take the shop apart looking for these.
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