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

Paul.. thanks for your feedback (as well as everyone else).. This forum
is not the sole basis of my research. Thanks for wanting to ensure I
dont muck it up.

I agree it seems unusual to have an adjustable pitch prop SLOW you down
compared to a cruise pitched prop, but I have no reason to doubt the
veracity of my source on that.

The powerplant for this velocity WILL be a Mazda 13B (have a core and
mount already) or Renesis (if its available when we fly) so a hydraulic
CS is out of the question. Even with 200-250 HP normally aspirated, we
wont be dealing with the harsh vibration and power pulses of a 4 banger
(I)O-360.

I am a solid fan of having constant speed propellers, and would really
prefer to have one on this aircraft. However, until I made this post, I
had yet to hear ANY favorible feedback on the IVO. Now there is
something to go with. I CAN save my pennies for an MT, but if money was
no object, I'd probably be buying a PT6 engine or some crap like that.
So.. obviously.. safety and quality on a budget. I would really like to
get in contact with the folks who have used these props (ESPECIALLY with
the Mazda) to sit down and pick their brain.

Dave




Paul Lee wrote:
The main problem with the Ivo is extreme vibration - not the power
limitation. I never heard ANY inflight adjustable prop that would
reduce cruise from 213 down to 170 - inconceivable. Its usually the
other way around.

H-U-G-E four bangers like the Lyc. IO-360 need very ridgid props
because they induce oposing "bang" vibration and can shake the prop
out of alignment. Ivo will not sell a prop for Lyc IO-360. There is no
problem with 6's because they are MUCH smoother - about 120 degrees
out of phase compared to 180 degrees of a four banger. Just compare
any 4 cylinder car and 6 cylinder of similar size for smoothnes.

Smaller engines like 0-320 do not produce as much vibration because of
their smaller size. IVO props really like the 220HP Franklin because,
in addition to being a 6, it has a fluid vibration damper system built
into the flywheel - very smooth engine. Thats what I have in my plane.
A smoother engine has important benefits - longer parts life due to
less vibration. A lot of parts failures can be traced to vibration.

Here are a couple of Velocities with the Franklin 220HP and
IVO props:
http://www.ida.net/biz/arlfrd/ (sold)
http://www.lavoiegraphics.com/velocityrg/

If you don't fancy Franklin, the Continental IO-360 is also a 6
- but a little heavier.

----------------------------------------------------
Paul Lee, SQ2000 canard project: www.abri.com/sq2000

Dave S wrote in message link.net...

I am involved with the building of a velocity, and questions are flying
around about propeller choice. For in-flight adjustable, we are limited
at this time to an electric control, such as MT or IVO. Cost is pushing
our options in this area towards the IVO.

I have heard of some vibration/resonance probs with certified engines (i
believe it was a lycoming, but dont know specifics)..

And one emailer has mentioned when they used the engine on a mazda
powered a/c they were limited to 170 mph with the IVO but got 213 mph
with a cruise wood prop.

I am looking for any other experiences.. good bad or otherwise regarding
the IVO inflight adjustable props (particularly in the 200 hp range).

Experiences with any other electrically controlled props that can handle
200-220 hp would be welcome too.. but the MT is probably outside my
price range..

Dave

Bart,

One factor that may influence IVO prop success is properly remounting
it after removal. The info I got from Johnny at northwest-aero.com
- a news post - is that the knurled plates are really needed and
that when the prop is removed it should marked and later remounted
in exactly same position/orientation it was before. Otherwise the
"knurls" do not seat together the same way and they wear off and
the prop goes loose and you will likely have problems.

"Bart D. Hull" wrote in message ...
I'll second the factual notion.
....

In article ,
(Paul Lee) writes:


Indeed,

With all due respect....

"I don't have first hand experience..."

Please, Please do "correct" research on the IVO before you make
conclusions on rumours. For example N570 has over 570+ hours on a
220hp Franklin with IVO without problems and N6Q has 160+ hrs.
Obviously there are successfull high HP IVO uses. Again, its not the
horsepower, but the smoothness of the engine. See my other post above.

Please try normal objective language instead of using emotional,
prejudicial terms like "mickey mouse ... inspection" or "do ....
research on ALL THE PROBLEMS .... IVO Prop" - rather than of "do
research on problems AND successes of IVO". IVO is quite open and
honest to tell you that they will not sell their props for certain
engines.



Sorry if I offended you but I wouldn't touch that prop with a ten foot pole. I
did clearly state that I did not have first hand experience with the prop and
simply urged the requestor to do a very complete job of research on the prop
before buying one. I will not argue that there are some "successful"
installations of the IVO prop, there are and that is an indisputable fact.
There have also been many reported problems with the IVO prop which must be
totally understood before buying one. The poster did not specifically state
which engine he was using only the report HP range. That range is most
frequently associated with the Lycoming O-360 and IO-360 engines which
according to YOUR OWN post have serious problems with the IVO Prop. Now where
the HELL to you get emotional and prejudicial from that. And Yes, I still
maintain the foil tape inspection process on the IVO prop is a micky mouse
deal.


Bob Reed
www.kisbuild.r-a-reed-assoc.com (KIS Builders Site)
KIS Cruiser in progress...Slow but steady progress....

"Ladies and Gentlemen, take my advice,
pull down your pants and Slide on the Ice!"
(M.A.S.H. Sidney Freedman)

Since the hub area of the prop is "supposed" to be stationary, why can't
the hub area of the CF blades be wrapped in multiple layers of CF and then
bolted on as a "One piece" prop. Granted the individual blades couldn't be
removed later, but the price for three blades appears that replacing them
all at once would still be cost effective?

Also - anyone have more info on the 3 Rotor, 4P at Copperstate?

Scott V.


H-U-G-E four bangers like the Lyc. IO-360 need very ridgid props
because they induce oposing "bang" vibration and can shake the prop
out of alignment. Ivo will not sell a prop for Lyc IO-360. There is no
problem with 6's because they are MUCH smoother - about 120 degrees
out of phase compared to 180 degrees of a four banger. Just compare
any 4 cylinder car and 6 cylinder of similar size for smoothnes.

Smaller engines like 0-320 do not produce as much vibration because of
their smaller size. IVO props really like the 220HP Franklin because,
in addition to being a 6, it has a fluid vibration damper system built
into the flywheel - very smooth engine. Thats what I have in my plane.
A smoother engine has important benefits - longer parts life due to
less vibration. A lot of parts failures can be traced to vibration.

Scott,

I was the person that saw the 4P with the 3 Rotor Mazda at Copperstate. It
looked like it was just finished and still was in primer. A few details needed
to be cleaned up but it looked like it was built solidly.

Any questions a person who just "took a look" could answer for you just write
me at my email address.

Bart

--
Bart D. Hull

Tempe, Arizona

Check http://www.inficad.com/~bdhull/engine.html
for my Subaru Engine Conversion
Check http://www.inficad.com/~bdhull/fuselage.html
for Tango II I'm building.

Scott VanderVeen wrote:
Since the hub area of the prop is "supposed" to be stationary, why can't
the hub area of the CF blades be wrapped in multiple layers of CF and then
bolted on as a "One piece" prop. Granted the individual blades couldn't be
removed later, but the price for three blades appears that replacing them
all at once would still be cost effective?

Also - anyone have more info on the 3 Rotor, 4P at Copperstate?

Scott V.


H-U-G-E four bangers like the Lyc. IO-360 need very ridgid props
because they induce oposing "bang" vibration and can shake the prop
out of alignment. Ivo will not sell a prop for Lyc IO-360. There is no
problem with 6's because they are MUCH smoother - about 120 degrees
out of phase compared to 180 degrees of a four banger. Just compare
any 4 cylinder car and 6 cylinder of similar size for smoothnes.

Smaller engines like 0-320 do not produce as much vibration because of
their smaller size. IVO props really like the 220HP Franklin because,
in addition to being a 6, it has a fluid vibration damper system built
into the flywheel - very smooth engine. Thats what I have in my plane.
A smoother engine has important benefits - longer parts life due to
less vibration. A lot of parts failures can be traced to vibration.

The two IVO/Franklin 220HP successfull combos I mentined - N6Q and N570 -
are both canards. The IVO installation instructions mention that
the prop tip is expected to flex as much as 4".

(Jay) wrote in message . com...
...........
One thing that you've probably already heard, but I'll restate for
other readers, is that, on a canard, the prop lives in the downwash of
the wing and turbulence off the fuselage. As a result, each blade is
experiencing changing forces as it goes round and round. Over time
this may effect the endurance of the prop.

This is in contrast to a coventional tractor configuration where the
prop is biting into clean air. So I've heard wood props are the thing
for canards for at least that reason.