|
|
<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
<< Lancair Builders' Mail List >>
<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
Posted for "colmar" <jones@colmar.demon.nl>
Just de-cowled today, (with a view to finally sending my old-style nose gear
strut back to Vern for all those revisions of the oleo, incl. self-centering),
to discover that the horizontal element of the engine mount just above the strut attachment points (those parallel vertical planes) is severely cracked at both left and right ends where its welded to the rest of the engine mount assembly.
Anyone else had this experience ? Is it safe to assume that it IS due to nose wheel shimmy?
I have had shimmy only occasionally over the 200 hours so far (and never been
able to correlate it to anything in landing technique, tire pressure, etc). But whenever it happened I, without much experience of shimmy in other planes, found it quite violent - although no affecting runway tracking.
Could there be another factor involved? for example;
Since this cracked engine mount element is so close to the parallel vertical
planes defining the strut/mount interface, how sensitive is the fit of the strut into the engine mount gap? Since this gap is essentially defined by the
dimensions this engine mount element so close by, this element could obviously
be put under a lot of compression if the long holding bolts were clamped tight
onto an smaller-dimensioned strut fitting. I remember it being a tight fit when I was building, but are we talking here about "file-to-fit, or polish-to-fit, or push-fit or interference-fit" or just "bolt-in-place" ? In which case, what bolt torque?
Advice? (for eventual installation of revised strut in a new engine mount -
hopefully before Spring arrives ! )
Colin Jones (PH-COL)
LML website: http://members.olsusa.com/mkaye/maillist.html
LML Builders' Bookstore: http://www.buildersbooks.com/lancair
Please remember that purchases from the Builders' Bookstore
assist with the management of the LML.
Please send your photos and drawings to marvkaye@olsusa.com.
|
|