Ivo prop

Hello,

Any comment about this prop.
Will I be happy with an O200 on my Minicab (110kts expected)?

thanks
--
Minicab F-PRAZ
Philippe Vessaire Ò¿Ó¬

On Apr 5, 1:59Â*am, Philippe Vessaire wrote:
Hello,

Â* Â*Any comment about this prop.
Will I be happy with an O200 Â*on my Minicab (110kts expected)?

thanks
--
Minicab F-PRAZ
Â* Â* Philippe Vessaire Â*Ò¿Ó¬


The experience we had with an IVO wasn't good. It was on a
Subaru using a redrive, so the input was smoother than a direct-drive
would be, but still experience vibration caused by the blades shifting
between the clamping plates. There have been several reports of Ivos
throwing blades, and when you see how they're made it's easy to
understand. The blades are mostly a high-density foam with a really
thin skin of carbon fiber, and they're retained by means of two bolts
through aluminum bushings in each blade root. There's enough slop that
the blade can move tangentially in the hub, throwing the chordwise
balance off.
The Ivo pulled really well. Better than the Warp Drive we
replaced it with.

Dan

I have 140 hours on IVO in my homebuilt with 200hp Franklin. The prop
plates are knurled and I have never seen any blade shifting - make
sure to follow IVO instructions and for proper bolt torque and check
the torque once in a while. I have some vibration but not excessive.
There is an advantage to those plastic blades - had a near gear up
landing and the blades broke "nicely" - no damage to the driveshaft
(had it magnafluxed). The main advantage with my inflight adjustable
IVO is good takeoff performance (I need it with my fast canard) and
decent cruise. Some day when I have excess money I would like to try a
Catto or similar wood prop for performance comparison.

I have heard that IVO does not tolerate Lyc and other four bangers
especially big ones. The torsional pulses are too great for the
blades. A smooth six or auto adaption is not such problem. Ivo will
not sell you a prop for a Lyc four banger.
---------------------------------------
SQ2000 canard http://www.abri.com/sq2000

On Apr 5, 2:59 am, Philippe Vessaire wrote:
Hello,

Any comment about this prop.
Will I be happy with an O200 on my Minicab (110kts expected)?

thanks
--
Minicab F-PRAZ
Philippe Vessaire Ò¿Ó¬

On Apr 5, 12:31 pm, wrote:
I have 140 hours on IVO in my homebuilt with 200hp Franklin. The prop
plates are knurled and I have never seen any blade shifting - make
sure to follow IVO instructions and for proper bolt torque and check
the torque once in a while. I have some vibration but not excessive.

The prop we had was an earlier mode; no knurling on the
plates. No matter how snug we got the bolts we still had some
fretting. And because the bolts have clearance in the blade bushings,
you can't get the blades aligned axactly opposite each other with any
accuract, and the chordwise balance is off. You could pay for dynamic
balancing but it would be off again the next time the prop was apart.

I have heard that IVO does not tolerate Lyc and other four bangers
especially big ones. The torsional pulses are too great for the
blades. A smooth six or auto adaption is not such problem. Ivo will
not sell you a prop for a Lyc four banger.

Which goes to show how weak they are. I'd rather find a prop
with a lot more margin and would settle for a fixed-pitch wooden prop
before I'd use an IVO again. They did have a "Magnum" version that was
supposed to be OK for the direct-drive applications, but maybe they've
taken it out of those applications.

I've often thought it would be interesting to adapt a larger
helicopter tail rotor to a homebuilt propeller application.
Mechanical, manual pitch control that has fewer gyroscopic issues,
with its teetering action and automatic pitch differentiation to keep
it aligned with the shaft. I think I'd want to try it on an airboat
for a while, first. There are almost always unforseen issues. Maybe
someone has already tried it?

Dan

wrote:
On Apr 5, 12:31 pm, wrote:
I have 140 hours on IVO in my homebuilt with 200hp Franklin. The prop
plates are knurled and I have never seen any blade shifting - make
sure to follow IVO instructions and for proper bolt torque and check
the torque once in a while. I have some vibration but not excessive.

The prop we had was an earlier mode; no knurling on the
plates. No matter how snug we got the bolts we still had some
fretting. And because the bolts have clearance in the blade bushings,
you can't get the blades aligned axactly opposite each other with any
accuract, and the chordwise balance is off. You could pay for dynamic
balancing but it would be off again the next time the prop was apart.

I have heard that IVO does not tolerate Lyc and other four bangers
especially big ones. The torsional pulses are too great for the
blades. A smooth six or auto adaption is not such problem. Ivo will
not sell you a prop for a Lyc four banger.

Which goes to show how weak they are. I'd rather find a prop
with a lot more margin and would settle for a fixed-pitch wooden prop
before I'd use an IVO again. They did have a "Magnum" version that was
supposed to be OK for the direct-drive applications, but maybe they've
taken it out of those applications.

I've often thought it would be interesting to adapt a larger
helicopter tail rotor to a homebuilt propeller application.
Mechanical, manual pitch control that has fewer gyroscopic issues,
with its teetering action and automatic pitch differentiation to keep
it aligned with the shaft. I think I'd want to try it on an airboat
for a while, first. There are almost always unforseen issues. Maybe
someone has already tried it?

Dan

Tail rotors are symmetrical airfoils. I thought about it myself
when I was working on helicopters. I suppose you could do it, but I
don't think it would be very efficient. If you want to play with some
blades they show up on e-bay occasionally.

Dan, U.S. Air Force, retired

On Apr 12, 2:12 pm, wrote:

...... and the chordwise balance is off. You could pay for dynamic
balancing but it would be off again the next time the prop was apart.

Not exactly true with knurled plates - the advice is to to reinstall
the blades in the same "knurl position" as when taken off.

This brings to mind the "balancing disk" (from http://www.balancemasters.com/ultralights.html
) I have installed. It seems to work. There is notable more vibration
when I take it off. You can see a photo at http://www.abri.com/sq2000/balancer.jpg
(hit reload if you get a permission error) Is anybody else using one
of these?

On 29 May 2007 11:40:54 -0700, wrote:

On Apr 12, 2:12 pm, wrote:

...... and the chordwise balance is off. You could pay for dynamic
balancing but it would be off again the next time the prop was apart.

Not exactly true with knurled plates - the advice is to to reinstall
the blades in the same "knurl position" as when taken off.

This brings to mind the "balancing disk" (from http://www.balancemasters.com/ultralights.html
) I have installed. It seems to work. There is notable more vibration
when I take it off. You can see a photo at http://www.abri.com/sq2000/balancer.jpg
(hit reload if you get a permission error) Is anybody else using one
of these?
I had 4 of 'em on my 53 Dodge Coronet wagon. One on each wheel. Never
had a balance problem, but the Kelly's were pretty well balanced to
start with (seldom had to use more than a 1/4 oz weight to ballance a
bias ply first run Kelly.

--
Posted via a free Usenet account from http://www.teranews.com