What general type of motion are you trying to sense?  If it is not a
quick deflection type of motion then I am not aware of any reasonable
sensors short of doing absolute positioning and checking if your abs.
direction has changed.  (or something pretty general like a compass..)
My understanding is the heli sensors are basically a weight on the end
of a piezo material used as a strain gague.  They are not good at low
level changes.  You can get the heli to be 'perfect' because you are
setting the average response to a lot of high level yaw pulses from the
engine.  Take one perfect in hover, grab the tail (not really! not a
sane thing to do..) and slowly turn it.  It will still compensate for
the engine, but it will not resist your motion at all.  I'm don't know
anything that will (at a reasonable cost) short of a full gyro, so
what're you trying to do?


> I'm looking for the actual piezo module itself, not a "rate gyro."  There
> are dozens of model helicopter-type gyros on the market - they aren't usable
> in this application.