Hello Paul, Is there any Ivoprop users in the group. Any comment

from

the group are welcome.

--
Best regards,
 ddunbar                          mailto:ddunbar@echidna.id.au

Ivo props have serious problems around the hub. The flat part of
the blade goes into a negative angle of attack at about
180 MPH giving a brick wall effect. Might work OK with a 14 inch
dia. spinner. Nobody has tried that yet to my knowledge.

Paul Lamar

Robin Ream wrote:

Do you think the same masking effect of the large spinner might be

naturally

present using that prop on a pusher like the Velocity?

Robin

Actually the pusher engine and cowl has that effect already. That is just

one

of the problems with the IVO. The other is the variable version
is a variable TWIST prop and not a variable PITCH prop. Consequently
the twist AND pitch is always wrong throughout the speed range.

Particularly

at the higher speeds.

Be all that as it may if you don't mind giving up MPG and top speed
for a few thousand in first cost go for it. It does generate some thrust
at the lower speeds.

Note: The required angle of attack near the root at all speeds
in this table. Column H.

Tracy and I measured the twist and the pitch of the IVO along
the blade radii and it did not come close to these required numbers.
This was a while ago. Changes have been claimed to have been made so
by all means borrow one and measure it again.

BTW Claiming to have fixed a product is a classic company ploy when
it comes to criticized products. Actually a glance at the IVO
will tell you it is no where near optimum.

Paul Lamar

As a side question, regarding props. What pitch are the blades for the
 new variable prop being optimised for? Vance J

Don't know right off the bat I will have to search the CD.
No time right now but if you remind me after Copper State I will
see if I can find it.

Paul Lamar
 
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