Date: Mon, 5 Mar 2007 07:18:55 -0800
Being a Tri-Gear builder I can't comment on the mono, but I can correct a
minor misunderstanding regarding aluminum (aka, aluminium and, rarely,
Dural).
Aluminum alloys work harden; that is, when deformed the material gets
stronger, not softer as stated. Dural literally applies to the 2000 series
alloys and the lever in question is most likely 6061 not 2024 as implied.
Further, stiffness is not the same as hardness and stiffness being a
property of the base metal, is not affected by alloying, work hardening or
heat treatment. In technical terms, all aluminum alloys have the same
modulus of elasticity.
Best regards,
Rob Housman
Europa XS Tri-Gear
S/N A070
Airframe complete
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Stephan Cassel
Sent: Sunday, March 04, 2007 3:19 AM
Subject: Re: Europa-List: Re. mono gear collapse - One way to make the lever
stiffer
Hi
I think both David and Graham have made the right conclusions.
The key thing is to make the gear lever as stiff as possible and no play
when it is in gear-down locked position.
One way to make the lever much stronger is NOT to bend the lever as per
manual. Keep it straight.
Moment may twist the lever, not much but enough to introduce a small play
when forces in not in one plan.
The optional strut will help but the strut is quite week. And Dural gets
much softer when you try to bend it.
The trick is to mount the lever on the other side of LG08S and use one
counter sink bolt and file the edge of the lever slightly, see link below
http://scassel.se/europa/cap4/images/DSCN1129.JPG (The smallest distance
between lever and the landing gear frame will be about 2 mm)
The lever will then go throw the tunnel exactly as per manual.
http://scassel.se/europa/cap4/images/DSCN1130.JPG
And, as David Joyce said, the joint between lever and LG08S must be solid as
rock. Sanded contact surfaces and Araldite 420 make that possible.
Regards Stephan
LN -STE. Permit to fly.
First flight when weather permits and then Pete Jeffers will kindly take
here up for the virgin flight.
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