Re: COZY: Cozy III: Need to replace the wooden propeller


Jim Rodrian
 

Last year I replaced the propellers (Performance Propellers) on my Defiant, N403R, with Catto props with the Nickel leading edge.  Cruise speed increased from 160 kts to 167 kts and top end speed increased from 180 kts to 190kts.  However, two weeks ago, following a high-speed test at 192 kts TAS, I noticed the Nickel leading edge on the rear prop had cracks.  One blade had four cracks in the Nickel, about 1 inch apart.  The other blade had two cracks in the Nickel.  The prop is arriving today at Catto to have the Nickel leading edge removed and replaced with urethan tape.

 

Jim Rodrian

N403R

 

From: canard-aviators@...
Sent: Wednesday, March 14, 2018 10:14 AM
To: cozy_builders@...; canard-aviators@...
Subject: [c-a] Re: COZY: Cozy III: Need to replace the wooden propellor

 

 

Scott Humphrey wrote:

 

I am still in the middle of the CI and have to fabricate rudder pedals so I am a good 2 months away from flying. 

 

But I would like to hear some recommendations from Cozy III owners on props that worked well for them before I call Catto.

 

As they used to say, no-one ever got fired for buying IBM. Same thing here - you can't go wrong with either Catto or Hertzler. Either can make you an appropriate prop for a 150 HP COZY III, and can bias it toward cruise or climb as you desire.

 

I would say that if you plan on flying in rain any substantial amount, you may want to seriously consider Catto's props with the nickel leading edge. While Hertzler's props have urethane on the LE, the rain will erode the paint a fair amount, leading to cosmetic issues. Nickel's not cheap, though.

 

I would HIGHLY recommend a 2-blade prop. They're cheaper, easier to ship (and cheaper to ship), are quieter with ANR headsets, and have no noticeable difference in performance. They also tend to stay a bit cleaner with 4-4 exhaust pipes, if you clock them correctly.

 

Oh, and for what it's worth, BOTH Hertzler and Catto recommend belleville washer usage on the prop bolts, although I get no kickbacks for recommending either one :-). At least yet...

 

My $0.02.

 

--

Marc J. Zeitlin                      marc_zeitlin@...

                                            http://www.cozybuilders.org/

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