Mike Wills motor mount.

X-Mozilla-Keys:

Did you send a picture of this mount? I'd love to see it.
Marc


No pictures yet. Mike is working on a prototype.
Can you find any engineering flaws in my drawing? :-)
Anybody?


I guess my concern would be with vibration frequency
causing the metal to work harden over a period of time.
Archie


 Mike Wills wrote:


Is there a way to quantify that and estimate the life of such a mount? And
since the entire airframe is an aluminum monocoque doesnt the same thing
apply there?

Mike Wills


One of the differences is the level of vibration and the
frequency. Aluminum brackets holding large masses 
such as alternators on engines are notorious fatique 
failure items. 

The automotve industry tests these sorts of things by 
driving the car over a very crude and rough Belgian
paving block test track for a distance that correlates to
several hundread thousand miles of typical customer 
use. Usually at that point in time everything
and all body parts are a mass of cracks.

I was given a Pontiac Firebird that had gone 
5000 miles on this test track and the fenders, roof,
panel behind the rear seats, you name it were
cracked and all accessories had nearly fallen off 
the engine. Things are merely beefed up when they
fail prematurely. 

If you instrument it and run the engine and
gather a lot of data you might be able to 
predict the life but I doubt it. The bolted connections
make it way too complicated to analyze easily.

Bill is an expert in computer finite element analysis. 
He might be able to do it given enough time and money.

It is a lot safer and cheaper to go with what is known 
to work over the past 100 years in aircraft development
on items like motor mounts when there is little to be
gained by doing otherwise.

Having said all that I would still like to see if it
can be done :-)

Paul Lamar

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