On a C&C 39 (A4, Martec folding prop) back in the late 70's we would mark the shaft coupling with lines indicating when the prop blades were vertical. For a long offshore race like Transpac we would send one of the crew over the side to put a rubber band or two around the blades to keep them closed. Usually it was the youngest crew member or the newbie that had to take the plunge.
Martin Calypso 1971 C&C 43 Seattle [Description: cid:D1BF9853-22F7-47FB-86F2-4115CE0BAF2F] From: CnC-List [mailto:[email protected]] On Behalf Of Charlie Nelson via CnC-List Sent: Tuesday, July 08, 2014 11:15 AM To: [email protected]; [email protected] Subject: Re: Stus-List Folding prop horizontal vs vertical plane.. Sounds correct--I just was defining a plane differently than you. For example, if there was a piece of paper clutched by the blades, the paper would be held in an approximate vertical plane when folded to minimize drag. Martec's instructions 1) keep the lower blade from falling down and 2) project the least area in the direction of boat motion (and would hold the paper in a vertical plane as well). Charlie Nelson [email protected]<mailto:[email protected]> -----Original Message----- From: Jean-Francois J Rivard via CnC-List <[email protected]> To: cnc-list <[email protected]> Sent: Tue, Jul 8, 2014 1:14 pm Subject: Stus-List Folding prop horizontal vs vertical plane.. My prop is folding, not feathering. On a non-geared folder If you have the blades on a vertical plane, the lower blade will hang down from gravity / add additional drag. On horizontal plane they fold together completely (Looks like a seaweed) and minimize drag. If it's a geared folder, they will fold completely no-matter the angle That's per Martec's instructions. See comment about the Pivot point (Shaft) being set vertical (Making the blades horizontal) http://www.martec-props.com/install_eliptec.htm As for the rebuilds, they are about a hundred bucks with Martec. They re-drill the hub, install a larger diameter shaft, re-drill the blades, balance and polish the whole thing. The prop looked brand new. Call the MFG to get an idea if you are out of specs. My blades wiggled more than 1 inch at the tips so it was pretty obvious.. -Francois Rivard 1990 C&C 34+ "Take Five" Lake Lanier, Georgia. _______________________________________________ This List is provided by the C&C Photo Album Email address: [email protected]<mailto:[email protected]> To change your list preferences, including unsubscribing -- go bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
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