IVO props... comments..

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

"Dave S" wrote in message
ink.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

Dave,
Robert and Valerie Harris of "The EZ Hangar" tested some props for IVO on
Long-EZ's. They found that the IVO's could handle the O-320s ok but they
could not hold up to the beating a prop takes from a O-360 (180 or 200hp).
If you are running a six cylinder such as the Contenintal O-360 or the
Franklin, things might be different.

Suggest you call Robert. I am sure he would be glad to talk with you about
their experiment. 901-475-3686

Rick Pellicciotti

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.

One of the parameters of a propeller is the "helix angle." To give a
muddled explanation, think of the propeller as "screwing" its way
through the air. At really high forward speeds, the propeller needs a
lot of twist to maintain a constant angle of attack along the entire
blade. At lower forward speeds, it needs much less twist.

If you have a prop with a low speed helix angle and start trying to take
it too fast, not all parts of the prop will be pulling their weight
equally. When you're checking your potential props, ask about helix
angle. The 170 vs 213 MPH sounds like that could be a big part of it.

For example, on light twins, apparently the prop blades have helix
angles set for about 100 - 120 MPH. This is so they will have some
single engine climb performance. A single, on the other hand, might have
the helix angle selected for cruise.

Ed Wischmeyer

"Dave S" wrote in message
ink.net...
.. . .
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..

The EAA has a lot of knowledge in this field. I suggest you contact Aviation
Information Services, 920-426-4821, for information.
Mostly, all you'll get here is anecdotal data and/or uninformed opinion. Or
mebbe a hard time. ;o)

Rich S.

In article . net, Dave S
writes:


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



Please, please, please do a substantial amount of research on all the problems
associated with the IVO Prop before making a decision. I don't have first hand
experience but from what I have read and heard from some very knowledgable
sources in the industry it is a prop to be avoided, especially for the 200 -
220 hp engines. I am sorry but I have not kept any of the various reports and
data on the prop because I eliminated it from my list a long tim ago. One
thing to look at though is that micky-mouse foil tape inspection required for
that prop.


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)

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.

osite (RobertR237) wrote in message ...
Please, please, please do a substantial amount of research on all the problems
associated with the IVO Prop before making a decision. I don't have first hand
experience but from what I have read and heard from some very knowledgable
sources in the industry it is a prop to be avoided, especially for the 200 -
220 hp engines. I am sorry but I have not kept any of the various reports and
data on the prop because I eliminated it from my list a long tim ago. One
thing to look at though is that micky-mouse foil tape inspection required for
that prop.


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)

I'll second the factual notion.

I have personally talked with 4 Ivo-prop flyers. The gentleman with the
Long-EZ did have problems with the blades loosening (even with the
knurled plates.) I don't remember the engine size but it was a Lycoming
4 cyl. As is mentioned the wing "wake" is a serious concern with any prop
that is rear mounted.

The other gentleman had no issues with a Ivo on a RV-4 with a Lyc. He was
pleased with its performance and did not have any issues with the stainless
tape moving.

I also talked with a gentleman at Copperstate this year with a Ivo on a
Lancair 4P with a 3 rotor Mazda auto-conversion. No problems, but hey a
9 cylinder (equivalent) equivalent engine is gonna be smooth. 300+ dyno
horsepower.

and the gentleman that owns SDS Electronic Fuel Injection Systems is flying
behind a Ivo as well.....


I spent a great deal of time finding out the facts behind the IVO and I
bought one.

Did ya know Warp drive was designed and owned by Ivo as well? I have NEVER
found ANYONE that has actually had a Ivoprop fail on them.

just my 2 cents.

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.




Paul Lee wrote:
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.

osite (RobertR237) wrote in message ...

Please, please, please do a substantial amount of research on all the problems
associated with the IVO Prop before making a decision. I don't have first hand
experience but from what I have read and heard from some very knowledgable
sources in the industry it is a prop to be avoided, especially for the 200 -
220 hp engines. I am sorry but I have not kept any of the various reports and
data on the prop because I eliminated it from my list a long tim ago. One
thing to look at though is that micky-mouse foil tape inspection required for
that prop.


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)

"Bart D. Hull" wrote

Did ya know Warp drive was designed and owned by Ivo as well? I have NEVER
found ANYONE that has actually had a Ivoprop fail on them.

just my 2 cents.

Bart

Bart, I was looking at a Dragonfly that shed it's Ivo prop; I was told to
investigate it carefully because last they saw it... "we were waiting for
them to arrive we saw a streak on final and as they landed the three blades
of the Ivo prop went sailing somewhere."

I also heard that there was no good way to assemble and align the prop
before mounting it on the engine but rather it had to be built right on the
hub with no really good way to align it in all dimensions.

You mentioned that stainless steel inspection tape. Seems copper tape was
used initially but broke too often. Was switching to steel fixing the
symptom or the problem?

Comment(s)?

Eric

I looked on the net for supporting info and found the following (which,
granted, is a few years old):
------------------------------------------------------
From: Dennis Jackson
Subject: Adjustable Props..
Date: 1997/09/08
Message-ID:
References:


Reply-To:
To: "prof S. A. Campbell"
Organization: TMS
Newsgroups: rec.aviation.homebuilt


prof S. A. Campbell wrote:

In article ,
Dennis Jackson wrote:

Can anyone suggest a reasonably low cost in-flight adjustable pitch
prop 2or3 blade in the 250-340 h.p. range? Thanks, Mike


I say the IVO Magnum prop will kill someone soon if it hasn't already.
It is very dependent on careful assembly and constant monitoring to make
sure it's not coming apart. It might be OK for ultralight engines but
forget it for high horsepower apps.

DJ

OK DJ, what is your basis for making this claim? Have you owned a
Magnum? Do you personally know someone who has had problems with them?
If so, with what engine? A number of people have tried putting them on
O-360 and IO-360's with decidedly mixed results, but if you stay aware
from these engines, I have heard nothing but good things about the
Magnum. Are you just ranting, or do you have real information?
Steve


Steve:
I guess I might as well drop the whole enchilada and get it over with.
Wait just a minute while I put on my asbestos underwear. I am not a
mechanical engineer, so my opinions should only be given the weight they
deserve, but I do speak from experience and know two people personally
who have had similar experiences with the Magnum prop, both RV builders
using 160 hp Lycs. This discussion is also taking place on the RV-List
so you can get more opinions there (http://www.matronics.com). At least
I am not alone in my opinions. I am glad to say that I have not heard
of any fatalities due to this prop and I have seen a couple of them
flying so maybe Ivo has solved the problems but I still remain
skeptical.

Anyway, after my experiences I became concerned about others use of this
prop and wrote a warning letter to other RV builders. Here is the
letter I sent at that time to Ken Scott at Van's Aircraft who published
an edited version in the RVator.


11/22/95

Ken:

Here's a little writeup on my adventures with the Ivoprop Magnum
propellor. If you could use it in the Rvator then feel free. I think
something should be published as a warning. This prop is not safe.

I installed an Ivoprop Magnum model MR-68-2 on my RV-4 with a Lycoming
IO320-B1X 160 hp engine (the X means that I changed the sump to fit the
RV-4). This prop is a 2 blade 68 inch dia ground-adjustable carbon
fiber unit that has steel torsion rods that run lengthwise in the blades
that can be twisted with a cam to adjust pitch. Each blade is a
separate piece held on by two hub bolts and separated by spacers which
are held under the two remaining bolts. The prop can also be set up as
a three-blade in which case no spacers are used. I had heard that some
people have experienced structural failures with this prop (of course
not until I bought one) so naturally I was concerned but figured I could
put a few hours on the prop without worry. Wrong.

Before I started the engine, I received a factory directive to install
tell-tale copper tape strips across the prop root junctions. This tape
will break if there is any movement of the blades. I ran the prop on the
ground for approx 10 minutes and then flew two times about 15 minutes
each. At no time did the engine speed exceed 2400 RPM, therefore power
to the prop was limited to no more than 135 HP. Upon ground runup I
found that the tape had broken on all joints. I then checked the bolt
torque and retaped the joints. The engine was again run up and 3 of the
4 joints failed again. After retorqueing and taping the airplane was
flown (first flight by Mike Seager) for about 15 minutes, landed, and
found all four joints broken. Retorqued, retaped, flew again (me this
time) for about the same amount of time with the same results.

I then removed the prop and I found that the prop blades showed friction
burning on the surfaces around the bolt lugs with a residue of black
(carbon?) dust around the area. The hub and front spinner plate showed
similar rubbing and residue where in contact with the prop blades.

While I like the basic idea of a ground or in-flight adjustable
propellor, I think this design is flawed in that there is too much
leverage at the base of the propellor for the clamping forces of the two
bolts to hold. Taking measurements on the hub, bolts, and prop bolt
barrels, I found that the bolts measured 0.496 o.d. and the hub and prop
barrels were 0.500 i.d., thus leaving about .004 inches slop in the
fit. This allows enough movement to overcome the clamping friction. If
this were a zero tolerance fit, it might work. I would be more
comfortable with extended bolts barrels that were a zero tolerance fit
into the hub holes.

The only thing preventing rotation of the propeller blades with engine
power pulses is the friction between the blade and hub on one side and
blade and spinner plate on the other. Perhaps this arrangement is
reliable with shorter blades and smaller engines such as 2-stroke
engines on ultralights, but it is insufficient on larger engines with
heavier power pulses and the larger and longer blades necessary with
higher power. There is simply too much inertia in the blade and too
much leverage on the small base at the hub. The blades will work back
and forth with each power stroke.

Another area of concern is the minimal edge distance of the bolt barrels
to the prop base. There does not appear to be any reinforcing around
the barrels. How are the barrels anchored into the prop? Are the
barrels connected together? If not, then what will prevent the barrels
from working loose in the prop and fracturing the base with a resultant
loss of a blade?

I talked with another RV-4 driver in Kentucky and he experienced the
same chafing due to movement of the blades against the hub and in
addition found that one bolt barrel was starting to loosen in the hub
and the hub had fractured across the base parallel to the barrel. He
had put less than 3 hours on the propeller.

Another negative is the necessity of leaving the spinner off to
facilitate inspection. For aesthetic and aerodynamic reasons this is
not an option for me.

I called Ivoprop and spoke to Ivo about the situation. He stated that
the copper tape was giving false readings and they are now recommending
stainless steel tape which will not break so easily!? He said that it
was normal for the blades to have some movement at first while seating
and then they should stabilize. He said that they have other ideas to
make the prop safe but I told him that I was just too much of a chicken
to test his theories and was not comfortable flying with his prop. To
Ivo's credit, he did not hesitate to offer a refund when I expressed my
desire to return the prop even though it was long past the 30 day
money-back guarantee period.

To sum up, it is my opinion that this design is UNSAFE. Anyone with the
Ivoprop Magnum propeller should immediately ground their aircraft and
remove the propeller. It is not a matter of IF it will fail, the
question is just WHEN will it fail. It is very likely that a fatality
will result if a blade suffers a catastrophic failure in flight, as the
resulting vibration can and probably will tear the engine from the
aircraft. Do not fly with this prop even one more hour!

Your pal,
Dennis

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)