Charlie & Tupper England wrote:
Hey Tracy,
Speaking of 'feature creep' on your new engine/air data box, how
about
this for the reduction drives (updated to use strain guages?).
Charlie
Hi Charlie,
Oh sure, load something else on my plate : )
I already added HP readout to the EM2 (based on fuel flow & BSFC). I
know
this is still a theoretical rather than actual HP readout but for our
purposes it is very usable.
And I like the strain gauge idea. Paul's annular piston would work
perfectly but would be impractical to implement. But a strain gauge on
the
back of the adapter plate would be very easy and I just might experiment
with that. Only possible glitch is that the hydraulic axial damping
system
on the input shaft (using oil pressure) causes an additional thrust on
the
sun gear that would have to be factored out of the reading. No big deal
if
the function were integrated into the EM2 which has access to oil
pressure
info.
But back in the real world, all my 'feature creep' energy on the
geardrive
is going into a chip detector system which will be an orderable option
when
ready. It is retrofitable to earlier drives too. Between that, the
2.85 :
1 RD-1C and the EM2, I'm tapped out just now. The strain gauge
experiment
will have to wait awhile. Any volunteers?
Tracy
Why do you think this is impractical to implement? It is not nice
to make hit and run statements like that :).
This is pretty easy to implement. No need for delicate strain gages and
strain gage amplifiers. (I did not just fall off the electronic
instrumentation
turnip truck. :)) I am not asking for any electronic changes. Just a
simple
addition to the gear box.
Paul Lamar
I meant impractical in the sense of what I have time for. Mechanical
changes tend to snowball. The adapter plate has to change to accomodate
annular piston assembly. The annular piston assembly would run into the nose
of the damper so the damper would have to be changed. The oil seal moves
back further on the input shaft where it is now splined so it would have to
be changed.
The strain gauge would simply be epoxy bonded to the back side of the
adapter plate. The EM2 already has spare inputs with instrumentation op
amps. Only thing to change would be the gain setting resistors for the
proper sensitivity.
If I only have one life to live, let me spend it flying instead of standing
in a machine shop : )
Tracy
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