This is what had me puzzled. Four 6-32's shouldn't be that stressed (I could have
used 4-40's, but they didn't "look right"). No gap between the wing bottom and the
fuse mount: across the fuse, there are 1/2" wide ply plates at the dihedral angle
where the bolts are, so the wing fits "perfectly".
I suspect that with this good fit, I'm getting a "scissors" action-- probably, a
"ground loop" on landing twists the wing and starts a shear. I've observed this
"offset" on other bolts that haven't failed yet. The wing, BTW, is the two-piece
wing, so each wing half primarily stresses only two bolts.
I think the bolts are more than strong enough for launch and flight stresses, and are
actually doing their job by failing before the wing structure does.
"Doctor, my arm hurts when I do like this." "Then don't do like that!"
IOW, quit dorking the landings... :)
Thanks,
--Bill
On Mon, 4 Sep 2000 18:19:55 -0700 Dick Barker <[EMAIL PROTECTED]> wrote:
Bill,
Four 6-32 nylon bolts is a huge overkill for a Chrysalis HLG. Must be
some other problem. Does a gap exist between the bottom of the wing and
the place where the nylon screw is fastened to the fus?. My UpLinks use
only 2 6/32 nylon screws and get a lot more stress than you can put on
them with a Chrysalis. If there is no air space between the wing mount
and the fus then the shear strength is totally predictable. There is
no way that four 6-32 screws even with a super hard discus launch such
as shown at:
http://www.uni-paderborn.de/StaffWeb/streit/Bilder/DM_2000/1-12/P7301137.JPG
--
Dick Barker
Seattle, WA
- The Old Fart Glider
http://www.eskimo.com/~dickb/UpLink.html
Bill wrote:
>I've been flying the Chrysalis HLG a lot and am starting to get the hang
of it.
>
>One bad habit that I've working on is flying too low and too slow and
>stalling at about 2' altitude and making a mini-dork landing. No damage,
>but there is a tendency to shear one or both of the rear wing bolts. I
>have two 6-32 nylon bolts at the spar and two 6-32 nylon at the TE stock
>and evidently there is enough lift or twist to shear these rear bolts at
>the fuse mounting block. This has been the only damage from these hard
>landings.
......
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