Actually my major premise was to live with short legs and mount the socket
flush (creating a slight increase in the wing angle of attack during ground
ops), but if that was not to be then slide the leg downward in the socket,
which I no longer think is a good idea - I just removed a leg and noticed
that the leg does not engage the socket for the whole length of the socket.
There are just two lands at full diameter, one at each end of the socket, so
if one were to slide the leg downwards 1-1/2 inches, the lower land would
not even touch the bottom of the socket. Oops!
The lot number on my legs is 050897. Perhaps there has since been a design
change, but all of my earlier comments were predicated on the description in
Rob Niels' OFF LINE copy to me of his message to Lakeland on the subject
(Lakeland has yet to respond). A careful re-reading of that message leaves
me wondering if I understood correctly but it sounded like (and still does,
sort of) his gear legs have a tapered engagement to the socket (he discussed
the possibility of fabricating split inserts to fill the gap between leg and
socket), and your comments (below) also suggest it is tapered.
Best regards,
Rob Housman
A070
----- Original Message -----
From: "Fred Fillinger" <fillinger@ameritech.net>
Subject: Re: Short Tri-gear legs
> I see now that you were referring to socket tube placement by the
> book, but mount the leg lower in the socket, rather than a lower
> mounting of the socket tube. The original post referenced both
> methods, so maybe this clarification is useful.
>
> Maybe the "E" word still comes into this, and the question is best
> posed to Europa? Because I note that they've cut a taper in the leg
> inside the tube, and I wonder if that's to relieve some of the stress
> of bending where it exits the tube, and repositioning the leg alters
> that picture. Ignorant guess, but if they're just saving weight, at
> 9 lbs, it didn't do much.
>
> Regards,
> Fred F., A063
>
> Rob Housman wrote:
> >
> > My education is in engineering (BS, ChE) and my industrial experience is
in
> > metals (non-ferrous), so in that context this is an engineering
analysis. I
> > did not "do the math" but from my understanding of the fundamentals of
> > statics (yes, I know, some of the loading is dynamic but the dynamic
load
> > uses the same levers and arms), if the gear leg fits snugly into its
socket
> > it will behave as a single member. Thus, you are correct in saying that
the
> > fulcrum is at the fuselage skin. However, your assumption that the
shorter
> > length inside the tube affects leverage implies a different assumption,
to
> > wit, that the leg does not fit snugly in its socket. So, take your
pick:
> > snug fit means that the socket is an extension of the leg, and loose fit
> > means the lever arm within the socket is the length of the leg within
(and
> > the socket is loaded only at the lower end at the fulcrum, and the upper
end
> > of the leg where the bolt goes through). As long as the leg within the
> > socket does not fail it transfers the same forces to the ribs under
either
> > assumption about snugness of fit.
> >
> > Perhaps a structural engineer will read this thread and comment.
> >
> > Best regards,
> >
> > Rob Housman
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