Jim Weir wrote in message . ..
I've come across a marvelously cheap vibration sensor that I want to convert
into an engine vibration instrument for a Kitplanes article. The electronics
for me is relatively trivial...the mechanics of vibration are a little harder to
fathom.

snip

Comments and thoughts from the technonerds amongst us appreciated.

sig snip

How 'bout comments from an ignorant wrench-bender?

Have allegedly repeatedly measured 1st order vibration (referenced to
propeller rpm) of both recip and turboprop aircraft engines using a
single axis sensor mounted perpendicular to the crankshaft. The
indicated amplitude of the vibration was not appreciably affected by
the "clocking" of the sensor axis.

In short, mounted either near the propeller end (front), or the on the
accessory case (rear) it did not matter whether the axis of the sensor
was parallel to the cylinders (call it side-to-side), perpendicular to
the cylinders (call it up and down), or at any clock angle in between.

If this information is not useful, just remember what you paid for it,
and where it came from.

TC