IVO props... comments..

(Jay) wrote in message . com...
Can't speak specifically on IVO, although he's in my area and have
thought it might be interesting to stop by the factory and see whats
what. I like the flexibility with which you can configure the props.

I can speak specifically on an Ivo we had on a Soob with a reduction
drive. The prop produced lots of thrust compared to the Warp Drive
that replaced it, but we couldn't get rid of vibration. The
engine/reduction ran as smooth as silk, but the prop, assembled the
way it is, with blades bolted between plates, has a tendency to have
one or both blades swing just a bit out of alignment chordwise and
start shaking. Several times we had it apart and noted fretting marks
between the blade bushings and plates, indicating relative movement.
And this with all assembly as per instructions.
There may be few failures, but when you look at a blade end and
see only high-density foam with a thin skin of carbon fiber over it,
and realize that the bushings are relying on this to retain the blade
in the hub, I have to wonder if failures won't become more commonplace
as the props age and accumulate hours. And a few failures are too
many.
Ivo advises against leaving the adjuster in the neutral position,
with no tension on the pitch adjuster rods. I tried it in a runup and
got prop flutter. I wonder if flutter isn't possible in other
conditions as well, with such a flexible prop. It wouldn't be long
before the prop failed.

Dan