Autoprop

[Teke's Pride]

Does anyone know if an Autoprop will fit in the prop pocket of a Freedom 40 cat ketch? The pocket seems a bit narrow at its base.

[bad]

We are in he process of repowering, including a new feathering prop. There was a brand new Autoprop, 19 in, on CL that I almost bought. In the end I decided the hub design positions the blades too far aft in the aperture, and the blade shape was such that when it is feathered or goes from forward to reverse there would be interference. Even reducing the blade size to 18” had me still worried. Similarly, a Max prop will not fit. We opted for a 19” Featherstream, which has been fitted successfully to a F40 AC. Will hopefully be able to report in a month how it all works.

[Teke's Pride]

Thanks Bad!
I look forward to your report.

[Teke's Pride]

The naval architect at King Propulsion has responded to my email quote request and states that the Autoprop will NOT fit in the prop pocket of a Freedom 40 without modifying the rudder, which he does NOT recommend. He sent me a photo of a Freedom 40 prop pocket with an overlaid diagram of an Autoprop to show why. Unfortunately I can't figure out how to post it here.

[Castaway]

I have found a KiwiProp (feathering) very successful on my F33 (UK F35), despite some unenthusiastic reviews. It has the advantage that it will fit where an ordinary propeller will fit, and the pitch can be adjusted to suit a particular hull/engine combination. Also, single blades can be replaced in case of damage. I've had mine for five years, and it's going well.