Low HP Variable Pitch Propeller

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matthass

Member
Joined
Oct 11, 2009
Messages
12
Location
Australia
Hi All,

Im looking for alternatives for a variable pitch prop for low horsepower engine (40 - 65 hp).

Anyone have any good suggestions?

What Ive found so far:
Neuform - for CT
Air-contact - since dissapeared as has Kiev...

Or just the hub?

Thanks!

Matthew
 

matthass

Member
Joined
Oct 11, 2009
Messages
12
Location
Australia
Thanks!

Duc looks interesting.
Cant bring myself to "bend" the prop as in IVOPROP. For me it shouts of imprecision (even tho its sure that other normal fixed pitch props bend in flight..).

Regards, Matt
 

Dan Thomas

Well-Known Member
Joined
Sep 17, 2008
Messages
6,234
Thanks!

Duc looks interesting.
Cant bring myself to "bend" the prop as in IVOPROP. For me it shouts of imprecision (even tho its sure that other normal fixed pitch props bend in flight..).

Regards, Matt
Ivoprops flex mostly in the outer regions of the blade, with most of the pitch change happening about 60% of the way out from the hub. This means that the inner regions don't change much, making them drag if the outer ends are pitched toward their upper limits. Not efficient at all.

And Ivos are mostly a high-density foam with a really thin skin of carbon fiber over it. The blades have two metal bushings bonded into the roots to hold them to the hub. Now, tell me: with so much centrifugal force, should one trust that bit of foam and skin to hold the blade? There have been such failures, and these props are also hard to balance chordwise. The blades tend to shift in the hub due to the bit of slop between the bushings and plates no matter how tight the bolts are, and if a blade moves ahead or back it moves the CG of the whole assembly off center. We had a terrible time getting an Ivo to work well and ultimately replaced it with a Warp Drive.

Dan
 

Dana

Super Moderator
Staff member
Joined
Apr 3, 2007
Messages
10,091
Location
CT, USA
Are you looking for a ground adjustable prop or inflight? If the former, there are quite a few options available, GSC Systems, Powerfin, Ivo, Aeroplast, etc. I believe GSC makes an inflight adjustable as well, but it may be for larger engines. I have a GSC ground adjustable prop (aluminum hub / wood blades) on one of my PPGs (25hp).

-Dana

A truly wise man never plays leapfrog with a unicorn.
 

BBerson

Light Plane Philosopher
HBA Supporter
Joined
Dec 16, 2007
Messages
15,274
Location
Port Townsend WA
The Hoffmann Co. has several mechanical actuated variable pitch props, mostly for motorgliders that need three positions. (takeoff, cruise, feather).
I have a Hoffmann HOV62 for the Limbach L2000 (2000cc/80hp)
Hoffmann probably has other props for any power.
BB
 

Jan Carlsson

Well-Known Member
Joined
Jan 11, 2009
Messages
1,860
Location
Sweden
Hoffmann isn't very efficient, at least not the fixed pitch props that have been replaced with Hercules propellers, others in Europe woodcomp, and DUC is said to be efficient, but stay away from GT.


Jan
JC Propeller Design
 

Woodenwings

Well-Known Member
Joined
Aug 2, 2006
Messages
167
Location
Toronto
"Cant bring myself to "bend" the prop as in IVOPROP"

Do you want a variable pitch prop for low HP or not! go on bend it!
 
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