WarpDrive ought to be able to give us a steer on the vibration
characteristics of their propellers. Unfortunately, when I last asked they
could not (I suspect they've never measured it).
Has anyone (e.g. Airmaster) got any data on the blade-flap frequencies of
the blades alone? These would be independent of any contribution from the
engine/gearbox. In any case there is an element of decoupling provided by
backlash in the gears and the 'dog clutch' so that the propeller is likely
to be the villain of the piece as far as harmonic vibrations go; the engine
is just the protagonist
.
I've noticed that a gust of wind into the back of the running Warp Drive
(on the ground, obviously) can set-off a vibration at about 2700 engine-rpm
Duncan McF.
(who is not happy with the Rotax gearbox, but the Agent thinks I'm just a
trouble maker!)
On Friday, February 14, 2003 4:23 PM, Peter Zutrauen
[SMTP:peterz@zutrasoft.com] wrote:
> I wonder what rpm ranges are the trouble points ("torsional peaks") for
the redrive with the airmaster prop, on the 914 with the softer mounts?
with the harder mounts?
>
> I wonder if anyone has done a tortional resonance/vibration analysis on
the combination... likely not I suspect. Is there a shop in the states
capable of doing such testing (like the Bob Harrison had done accross the
pond on the Jabiru 3300/MT combo)?
>
>
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