Hey all - thanks for the input. Note that Martec is out of business and there are no engineering drawings available on the internets. The martec-props website is a company in AZ that refurbishes old Martec props and retails Aussie Slipstream folding props.
…So I ‘crowdsourced’ the answer from a series of eBay listings, and based on the measurements in the photos it looks like ‘Standard’ Martec taper is 1/16 ratio. GPT told me a different answer- Which I will not repeat here in the interest of avoiding generation of fake GPT wisdom. In the end, I bought the Flex-o-Fold prop. If I find out the Martec measurements are different when I haul-out (in a few months) I will post an update here. -Eddie W. On Mon, Oct 6, 2025 at 1:55 PM Joel Aronson <[email protected]> wrote: > Word of caution-some shafts have a left hand threaded nut. It’s happened > to me twice! > > Joel > > > > On Mon, Oct 6, 2025 at 4:53 PM Peter W. via CnC-List < > [email protected]> wrote: > >> I installed a max prop (2 blade) . I don’t recall the taper of shaft to >> be of special note. I did have to cut off the shaft end . >> But not very much. >> Pete w >> Siren Song >> ‘90 C&C 30-2 >> Irvington va >> >> Sent from my iPhone >> >> On Oct 6, 2025, at 4:41 PM, Pete Shelquist-comcast via CnC-List < >> [email protected]> wrote: >> >> >> Eddie - >> Flexofold didn't ask me this when I bought mine, but that was a long time >> ago. It's held up really well btw. >> >> Couple suggestions; You could pull the existing prop and measure the >> shaft with a caliper and do the calcs. Or call martec and ask them what >> specs they manufacture to. They've been around long enough to have input >> on what's standard. >> >> Hope that helps. >> ------------------------------ >> *From:* ejwills1993--- via CnC-List <[email protected]> >> *Sent:* Monday, October 6, 2025 3:32 PM >> *To:* [email protected] <[email protected]> >> *Cc:* [email protected] <[email protected]> >> *Subject:* Stus-List C&C 30 Mark II - Shaft Taper? >> >> >> Hey C&C Sailors - >> >> I’ll be replacing my fixed Martec prop with a folding 2-blade prop this >> winter when it’s time to haul out. >> >> I’m being asked by Flex-o-Fold what my ‘Shaft Taper’ is. According to the >> boat user manual the taper is ‘standard’ but my understanding is that >> ‘standard taper’ can mean 1/10, 1/16, or 1/20. According to Flex-o-fold >> they need this shaft taper info for the correct adapter sleeve. >> >> The following info applies: >> >> -=-=-= >> >> 1. Boat - Make and Model C&C 30, Mark II >> >> 2. Engine - Make and Model - Yanmar 2GM20F >> >> 3. Transmission Reduction Gear Ratio - 2.62 : 1 >> >> 4. Displacement (Weight) 8300 lb >> >> 5. Water Line Length 25.75 ft >> >> 6. Shaft Size or Sail Drive Model - 1 inch conventional shaft >> >> 7. Propeller Rotation left hand or right Hand - Right Hand >> >> 8. Current Propeller Size and Type (i.e. fixed 3-blade, feathering, >> etc...) Martec RH 15D x 11P X1 (photo attached) >> >> >> I have also attached photos of the shaft drawing (from user manual) and >> Martec fixed prop. >> >> Martec Prop Photo <https://photos.app.goo.gl/tWbUW7CscPQz38MZ7> >> https://photos.app.goo.gl/tWbUW7CscPQz38MZ7 >> >> Shaft Diagram Photo <https://photos.app.goo.gl/WwZiFewzcUVDwdL87> >> https://photos.app.goo.gl/WwZiFewzcUVDwdL87 >> >> Thanks! >> >> >> -Eddie Wills >> >> C&C 30 Mark II ‘Mystic Star’ >> Your contributions help pay the fees associated with this list and help >> to keep it active. Please help by making a small contribution using PayPal >> at: https://www.paypal.com/paypalme/stumurray All contributions are >> greatly appreciated. >> >> Your contributions help pay the fees associated with this list and help >> to keep it active. Please help by making a small contribution using PayPal >> at: https://www.paypal.com/paypalme/stumurray All contributions are >> greatly appreciated. > >
Your contributions help pay the fees associated with this list and help to keep it active. Please help by making a small contribution using PayPal at: https://www.paypal.com/paypalme/stumurray All contributions are greatly appreciated.
