Richard My MaxProp was set to 14 degrees. Gear ration was 2.6:1
Joel On Mon, Dec 18, 2017 at 11:24 AM, Dennis C. via CnC-List < cnc-list@cnc-list.com> wrote: > Take prop manufacturers recommendations with a grain of salt. Years ago I > requested a recommendation from Flexofold. The rep at the time was Chuck > Angle who was highly regarded. He said he didn't have a good prop > recommendation for my 35-1. :) I went with Martec. > > In 2011, I repeated the request and got a recommendation for a 15 x 12. > In 2016, I again asked and they said 16 x 12. > > Currently, Touche' is swinging a 14 x 14 Martec which seems a bit under > pitched (or too small a diameter). I can run at 6.4-6.5 knots at cruise > rpm (80% max, 2450 rpm) and flat water, no wind. > > On my list for next year's haul out is to measure and document > (photograph) the prop tip clearance distance. I will also measure the hub > and swing pin location. The swing plane for different props varies. > > I think prop selection is part science, part art and a bit of voodoo. > > Dennis C. > Touche' 35-1 #83 > Mandeville, LA > > On Mon, Dec 18, 2017 at 9:59 AM, Rick Brass via CnC-List < > cnc-list@cnc-list.com> wrote: > >> The problem that I see with this calculator is that there is no value for >> prop diameter (and slip is pretty intangible, though I suspect using .10 >> slip might be a good approximation for 90% efficiency). >> >> >> >> The rule of thumb that a local propshop told me is that changing prop >> diameter by 1” is approximately equivalent to changing the prop pitch by >> 2”. So diameter also enters into the calculation. >> >> >> >> I believe each prop maker has their own calculator for recommending >> initial diameter and pitch, based on boat weight, engine HP and targeted >> cruising RPM, transmission reduction ratio, and hull speed. >> >> >> >> Rick Brass >> >> Washington, NC >> >> >> >> >> >> >> >> *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of >> *svpegasus38 >> via CnC-List >> *Sent:* Sunday, December 17, 2017 5:56 PM >> *To:* cnc-list@cnc-list.com >> *Cc:* svpegasus38 <svpegasu...@gmail.com> >> *Subject:* Re: Stus-List PROPELLER PITCH >> >> >> >> Try this propellor calculator. >> >> rbbi.com/folders/prop/propcalc.htm >> >> >> >> >> >> >> >> Sent from my T-Mobile 4G LTE Device >> >> Doug Mountjoy >> >> POYC >> >> Rebecca Leah >> >> Lf39 >> >> >> >> -------- Original message -------- >> >> From: Bunky via CnC-List <cnc-list@cnc-list.com> >> >> Date: 12/17/17 14:18 (GMT-08:00) >> >> To: cnc-list@cnc-list.com >> >> Cc: Bunky <richard.h.bernst...@uvm.edu> >> >> Subject: Stus-List PROPELLER PITCH >> >> >> >> Luna is a 1984 C&C 35 with a Yanmar 3gm30 engine. Does anyone know what >> the proper propeller pitch should be? She has an aftermarket Maxiprop, >> and based on engine performance, I believe the pitch may be set too high. >> >> Richard >> Luna, Lake Champlain, VT >> >> _______________________________________________ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://www.paypal.me/stumurray >> >> _______________________________________________ >> >> Thanks everyone for supporting this list with your contributions. Each >> and every one is greatly appreciated. If you want to support the list - >> use PayPal to send contribution -- https://www.paypal.me/stumurray >> >> >> > > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > > -- Joel 301 541 8551 <(301)%20541-8551>
_______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
