Hi Jim,

I've been thinking most of the flex was with the canopy frame rather
than the hinges -- but, after hearing the results of other builder's
experimentation/modifications I'm not so sure.  I suppose we could just
make some reference marks on a hinge and measure the distance between
them with the gas spring struts installed and without...  Once its
deformation was known we could assume the rest is the canopy itself.  

I don't know about the gas spring struts cylinder up/down position
affecting the canopy's alignment -- but it does affect the dampening at
full extension.  

I would like to make sure every Legacy builder knows that the manual is
incorrect in the orientation of the gas spring strut cylinder.  I
learned this from Leighton Mangels at the Lancair Fly-In.  I've been
meaning to send a notice to the LML but keep forgeting.  The design of
our gas spring struts (made by Suspa) provides for dampening at full
extension.  But it requires the the cylinder part (larger black portion)
of the gas strut be attached at the hinge.  Apparently there is some
kind of orifice and oil dampening system that has to be higher than the
rest of the strut to work.  I originally had mine opposite this, the way
the manual specifies it, and the canopy would just slam to the top.  I
switched it after Leighton's advice and now it comes to a nice cushioned
stop.  Thanks again Leighton!  He says he's told Lancair several times
but it still hasn't shown up in the manual.  I know those guys are
trying to do a lot with just a few people...

Don Barnes had a post this morning that says Lancair has a new more
effective modification.  I'm looking forward to learning more about it.
I'd like to put it in the math model and see how it looks.

By the way, my canopy hinge/strut analysis math model was built in
Microsoft Excel.  If anyone wants a copy to play/experiment around with
just let me know and I'll send it on.

Valin Thorn
Legacy 173

------------------------------------------------
Jim Thomas wrote:

[...If I read your post correctly, you feel the problem is with the
bending of the
hinge in the closed position and not deformation of the canopy stiffener
itself.  Is that correct?  

.... I installed the thick AN washers on my canopy and noted a vast
improvement in the fit.  

... I would like to see someone measure the deformation of the canopy
hinge under the various conditions; original design, modified strut
geometry, and AN washers installed.  ]