[Diy_efi] RE: [offlist] Strain gauge on engine mounts

[Daniel R. Nicoson]

>
> > Seems to me that the engine mounting rubbers will move in much the same
> > way that the prop shaft will twist.
> >
> > Why is the potentiometer / strain gauge from the inner wing to
> the engine
> > cam / rocker cover not just as good and a whole lot simpler to read?
> >
> > Hugh
> >
Your biggest problem with this process is that rubber is terribly non-linear
and it won't repeat readily.  Heat will have a big effect too.  How would
you calibrate the system?  Even if you were only looking for relative
numbers as stated in the original post, the non repeatability would be a
problem.

Working with the twisted steel shaft eliminates a LOT of variables.  Steel
is very well understood, well documented and as long as it is used in the
linear portion of its stress-strain curve, it could practically be
calibrated from the textbook assuming one knows the actual alloy and heat
treat.

Dan Nicoson