Does anyone have any reliable information on allowable runout on the propellor shaft when measured at the propellor end of the shaft? I banged my prop on rock in the Thousand Islands area of the St. Lawrence River. Propellor is repaired but now I have a high-pitched sound at idle speed. Maybe from cutless bearing? Or prop sing? No noticeable vibration, however. Am hauling out on Monday morning to have a look. Thanks for any information, Harry Hungate Bessie. NT 32-238

Hi Harry. I recommend you have the shaft checked to see if it is still true. And while you have everything apart, I recommend you change the cutless bearings and service your shaft seal. If it’s a PYI shaft seal they recommend changing the bellows. If you have to lower your rudder to get the shaft out, it’s also worth changing the rudder seal. When I did this work, I had to have my boat blocked higher than normal so I could successfully lower the rudder. There is a write up I did on the SENTOA maintenance section on the steps I did to get through this work. Best wishes Stephen Hill NT37-199 Tug’n Sent from my iPhone > On Sep 29, 2023, at 9:34 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: > > Does anyone have any reliable information on allowable runout on the propellor shaft when measured at the propellor end of the shaft? I banged my prop on rock in the Thousand Islands area of the St. Lawrence River. Propellor is repaired but now I have a high-pitched sound at idle speed. Maybe from cutless bearing? Or prop sing? No noticeable vibration, however. Am hauling out on Monday morning to have a look. > > Thanks for any information, > > Harry Hungate > Bessie. NT 32-238 > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org

hi this is NT 32 Nordic Star sometimes the edge of the prop after it has been reworked is too sharp you can run a file to square up the edge doesn’t take much good luck Sent from my iPad On Sep 29, 2023, at 9:34 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: Does anyone have any reliable information on allowable runout on the propellor shaft when measured at the propellor end of the shaft? I banged my prop on rock in the Thousand Islands area of the St. Lawrence River. Propellor is repaired but now I have a high-pitched sound at idle speed. Maybe from cutless bearing? Or prop sing? No noticeable vibration, however. Am hauling out on Monday morning to have a look. Thanks for any information, Harry Hungate Bessie. NT 32-238 _______________________________________________ Sentoa mailing list -- sentoa@lists.sentoa.org To unsubscribe send an email to sentoa-leave@lists.sentoa.org

Thanks for the tip! Harry Hungate > On Sep 30, 2023, at 11:26 AM, Weik Anne via Sentoa <sentoa@lists.sentoa.org> wrote: > > hi this is NT 32 Nordic Star > sometimes the edge of the prop after it has been reworked is too sharp > you can run a file to square up the edge > doesn’t take much > good luck > > Sent from my iPad > > On Sep 29, 2023, at 9:34 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: > > Does anyone have any reliable information on allowable runout on the propellor shaft when measured at the propellor end of the shaft? I banged my prop on rock in the Thousand Islands area of the St. Lawrence River. Propellor is repaired but now I have a high-pitched sound at idle speed. Maybe from cutless bearing? Or prop sing? No noticeable vibration, however. Am hauling out on Monday morning to have a look. > > Thanks for any information, > > Harry Hungate > Bessie. NT 32-238 > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org

nordic star here again. i also found that the ground strap on the shaft made noise after sitting awhile just wiping off shaft and noise gone Sent from my iPad On Sep 30, 2023, at 12:05 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: Thanks for the tip! Harry Hungate > On Sep 30, 2023, at 11:26 AM, Weik Anne via Sentoa <sentoa@lists.sentoa.org> wrote: > > hi this is NT 32 Nordic Star > sometimes the edge of the prop after it has been reworked is too sharp > you can run a file to square up the edge > doesn’t take much > good luck > > Sent from my iPad > > On Sep 29, 2023, at 9:34 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: > > Does anyone have any reliable information on allowable runout on the propellor shaft when measured at the propellor end of the shaft? I banged my prop on rock in the Thousand Islands area of the St. Lawrence River. Propellor is repaired but now I have a high-pitched sound at idle speed. Maybe from cutless bearing? Or prop sing? No noticeable vibration, however. Am hauling out on Monday morning to have a look. > > Thanks for any information, > > Harry Hungate > Bessie. NT 32-238 > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org _______________________________________________ Sentoa mailing list -- sentoa@lists.sentoa.org To unsubscribe send an email to sentoa-leave@lists.sentoa.org

Hi, and thanks, again. I eliminated the shaft wiper as the noise source first. Harry Hungate > On Sep 30, 2023, at 12:28 PM, Weik Anne via Sentoa <sentoa@lists.sentoa.org> wrote: > > nordic star here again. i also found that the ground strap on the shaft made noise after sitting awhile just wiping off shaft and noise gone > > Sent from my iPad > > On Sep 30, 2023, at 12:05 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: > > Thanks for the tip! > > Harry Hungate > >> On Sep 30, 2023, at 11:26 AM, Weik Anne via Sentoa <sentoa@lists.sentoa.org> wrote: >> >> hi this is NT 32 Nordic Star >> sometimes the edge of the prop after it has been reworked is too sharp >> you can run a file to square up the edge >> doesn’t take much >> good luck >> >> Sent from my iPad >> >> On Sep 29, 2023, at 9:34 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: >> >> Does anyone have any reliable information on allowable runout on the propellor shaft when measured at the propellor end of the shaft? I banged my prop on rock in the Thousand Islands area of the St. Lawrence River. Propellor is repaired but now I have a high-pitched sound at idle speed. Maybe from cutless bearing? Or prop sing? No noticeable vibration, however. Am hauling out on Monday morning to have a look. >> >> Thanks for any information, >> >> Harry Hungate >> Bessie. NT 32-238 >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org

Hi Harry, Huge bummer on the strike, glad your prop was easily repaired. I agree with NORTH STAR, I suspect "prop sing" over shaft or cutlass - that said, Stephen Hill's related article is absolutely outstanding stuff! And I agree with Stephen, if you end up pulling your shaft to check it, absolutely do the cutlass' whether you think they need it or not. To answer your specific question, the best advice I could find regarding unsuitable shaft runout (I had been specifically seeking cutlass bearing wear limits) was >0.010-0.015" was where you need to start monitoring and making decisions. In my talking to the long time prop guy here in the Seattle area, he said it takes a good whallop to damage a shaft on a trawler because the keel shoe typically helps avoid a crippling prop strike. Fingers crossed for your shaft. After we had our prop serviced for the first time, we immediately encountered 'prop singing'. In the shop, the prop dialed out well within spec with no tuning or modification required but it had been collecting small erosion grooves along the edges after 20 years and 10K engine hours. Came back with ~1/16" less diameter and the edges dressed quite square. Immediately experienced a skull-penetrating mono-tone high-pitched tone from ~700 to 900 RPM with no discernable vibration. It was loudest right under the cockpit directly over the prop and best described as ringing like a wine glass with a wet finger tip. Prop shop said "it happens sometimes", that if it was shaft or bearing, it would involve more 'vibration' and would typically vary some with RPM. Solution was to grind a small bevel on the trailing edge. He did it with the boat hanging in the slings. Here's an Australian educational link I found pretty useful, if it doesn't make it through SENTOA's filter, email me back. Good luck Kelly Britz, Seattle SANDPIPER, NT 37-049 <http://www.olds.com.au/marine/terminology.html>www.olds.com.au/marine/terminology.html There's a nice graphic but pasteing the relevant text here: "...The singing is a result of propeller diameter and R.P.M. , Boat speed and Trailing-edge thickness and shape or roundness. In most of the cases not much can be done on Diameter, Rpm's or speed, but we can modify the Edge Geometry. This has been the Strategy for all efforts to eliminate singing." "Most Propeller professionals (and others) are familiar with the Anti-singing Edge ?? Chamfering of the Trailing edge, typically on the Suction side. This shape avoids the creation of curving flow eddies by cleanly separating the water flow off the blade. The following graphic shows the Chamfering that goes from 0.5 or 0.4 Radius to the tip of Suction Side..." ________________________________ From: Harry Hungate via Sentoa <sentoa@lists.sentoa.org> Sent: Saturday, September 30, 2023 10:37 AM To: South East Nordic Tugs Owners' Association (SENTOA) <sentoa@lists.sentoa.org> Cc: Harry Hungate <wcx7106@gmail.com> Subject: [Sentoa] Re: Nordic Tug 32 propellor shaft allowable runout Hi, and thanks, again. I eliminated the shaft wiper as the noise source first. Harry Hungate > On Sep 30, 2023, at 12:28 PM, Weik Anne via Sentoa <sentoa@lists.sentoa.org> wrote: > > nordic star here again. i also found that the ground strap on the shaft made noise after sitting awhile just wiping off shaft and noise gone > > Sent from my iPad > > On Sep 30, 2023, at 12:05 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: > > Thanks for the tip! > > Harry Hungate > >> On Sep 30, 2023, at 11:26 AM, Weik Anne via Sentoa <sentoa@lists.sentoa.org> wrote: >> >> hi this is NT 32 Nordic Star >> sometimes the edge of the prop after it has been reworked is too sharp >> you can run a file to square up the edge >> doesn’t take much >> good luck >> >> Sent from my iPad >> >> On Sep 29, 2023, at 9:34 PM, Harry Hungate via Sentoa <sentoa@lists.sentoa.org> wrote: >> >> Does anyone have any reliable information on allowable runout on the propellor shaft when measured at the propellor end of the shaft? I banged my prop on rock in the Thousand Islands area of the St. Lawrence River. Propellor is repaired but now I have a high-pitched sound at idle speed. Maybe from cutless bearing? Or prop sing? No noticeable vibration, however. Am hauling out on Monday morning to have a look. >> >> Thanks for any information, >> >> Harry Hungate >> Bessie. NT 32-238 >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org >> _______________________________________________ >> Sentoa mailing list -- sentoa@lists.sentoa.org >> To unsubscribe send an email to sentoa-leave@lists.sentoa.org > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org > _______________________________________________ > Sentoa mailing list -- sentoa@lists.sentoa.org > To unsubscribe send an email to sentoa-leave@lists.sentoa.org _______________________________________________ Sentoa mailing list -- sentoa@lists.sentoa.org To unsubscribe send an email to sentoa-leave@lists.sentoa.org