A properly feathered MAX prop will not rotate as the blades have aligned with the thin edge towards the water flow. If the blades do not feather then it will rotate the same as a fixed blade prop.
As to the chance of a wrap, I put around 25K NM on MAX props back and forth across the NE Pacific and around the PNW (we do not have many lobster pots) with almost no wrap issues. Once on a delivery back from Hawaii a garbage bag caught on the feathered prop which had to be removed by a dive. For me the wrap issue has mainly been a line over the side when the “high speed underwater winch” was put in motion. There was that time up in BC where after a lunch stop in Squirrel Cove I was up in the bow weighing anchor. As the anchor got within sight I noticed a monofilament (shrimp pot?) line running aft just as the lovely Mrs. Calypso put the boat (1980 C&C 36) in gear. The MAX prop did what all props would do and grabbed the line and wound it tight. Had to dive on that one and lost a Leatherman in the process. PYI, Inc. who sells the MAX prop recommends the sharp line cutting devices. I have not used/needed them but if I regularly sailed around waters filled with crab/lobster pots, especially in poor visibility I would use the cutters. Martin Calypso 1970 C&C 43 Seattle From: CnC-List [mailto:[email protected]] On Behalf Of Neil Andersen Sent: Tuesday, March 26, 2013 1:36 PM To: [email protected] Subject: Re: Stus-List Feathering a Max-prop Won’t keeping the transmission in neutral cause the prop to rotate (as it is not ‘connected’ to the engine and thereby increasing the chance of a prop shaft wrap? Neil FoxFire, C&C32 Worton Creek, MD From: CnC-List [mailto:[email protected]] On Behalf Of Martin DeYoung Sent: Tuesday, March 26, 2013 2:47 PM To: [email protected]<mailto:[email protected]> Subject: Re: Stus-List Feathering a Max-prop On Calypso with its Perkins 4-108 coupled to a 71 series Borg-Warner Velvet Drive reduction gear we mostly do 1. & 2., but sometimes 3. With our Velvet Drive reduction gear, the MAX prop feathering process needs the engine running to provide the hydraulic pressure to brake the shaft (hydraulic pressure continues for a moment as the engine shuts down). The motoring/sailing speed provides the water flow to push the prop blades into the feathered position. After the engine has been off for a few moments the Velvet Drive no longer has enough hydraulic pressure to lock the prop shaft negating any effect of the gear level position. It is important to know what your own reduction gear manufacturer says regarding sailing in neutral vs. in gear. With a feathered MAX prop the prop shaft should not rotate whether the reduction gear is “in gear” or out. If you hear a rumbling noise after “old smoky” has shut down the prop may not have feathered correctly. Once in a great while, or after I have just serviced the prop and it is full of grease, I will need to start the engine back up, use reverse gear for a moment then back to forward and repeat feathering process. On occasion, especially when using a spinnaker, I place the throttle/gear lever in the neutral position to avoid having a spinny sheet wrap around it. (Calypso’s throttle/gear lever is located stbd/outer side of the cockpit just below a cleat used with the primary winch.) Martin Calypso 1970 C&C 43 Seattle
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