are feathering props and rope cutters " noisy"

[Oscarpop]

early this season we removed our fix prop and added a darglow feathering prop.

Works a dream. the only thing is the prop seems to make a noise when turning. Its a bit like a rattle or turning of gears. Can't place it, and I have been trying to all season.

Originally I thought that something was loose either in one of the stern lockers but, there is nothing there.

Then I thought that something was loose with the prop, maybe the anode. However, I went under the boat and its all firmly in place. We must have motored at least 300 miles this season. There is also no undue vibration from the prop.

Then I thought that maybe the rope cutter was making that kind of " edward scissorhands" noise when it was going round.

Its an Ambassador unit and I had to disassemble it to get the old prop off. I put it back as per all the instructions and the spacers are in the right place. There is also enough clearance between the prop and the rope cutter.

Any suggestions? I am fairly sure that I didnt have this rattle before I changed the prop.

 

[macd]

My last boat had a Darglow feathering prop and rope cutter (can't remember the brand, but two rotating blades scissoring against two fix ones): no noisier than it was before.

PS I presume you have the noise when the engine's running and driving? There shouldn't be anything when it's locked and feathered.

 

[neil1967]

Mine is very noisy, which I have attributed to a worn cutlass bearing, which I will replace this winter. I will also take the darglow appart to see if anything is wrong internally, although it seems to function OK. Interest to hear of any other instances

Neil

 

[Oscarpop]

Mine is very noisy, which I have attributed to a worn cutlass bearing, which I will replace this winter. I will also take the darglow appart to see if anything is wrong internally, although it seems to function OK. Interest to hear of any other instances

Neil

The boat is new, so I dont think its anything worn. Maybe its the prop?

 

[Twister_Ken]

I had a dreadful noise once when motoring. On investigation one of the bearings in the Ambassador Stripper - just a plain plastic bush - had disappeared (who knows where?) so the Stripper was bouncing on the shaft. Sounded like a man with a tapping hammer.

 

[Hadenough]

We have an Ambassador cutter on a 40mm shaft but not a feathering prop. No noise underway but being on a mooring in a 4 knot spring tide we found that the prop was turning. This was accompanied by a loud chattering noise something like you would hear when an HV electrical component is arcing (if you've ever had the misfortune to have heard that!). I have put it down to the "prong" of the Ambassador chattering in the fixed "wedge" perhaps because the shaft is turning at the vageries of the tidal current but without any load on it. Can't be certain but am pretty sure after a disturbed night of investigation.

 

[Oscarpop]

I called Darglow, and they were very helpful

It does seem as it feathering props can be noisier, however the sound from a feathering prop would be an increase in cavitation ( which I dont think will make the noise I am hearing)

I think that after consulting the ambassador website, I probably need to renew the bearings. They are meant to last a few years in normal conditions.

However I have a mud berth, and the prop is encased in mud for 16 hours a day.

It is likely that the extra silt has increased the wear on the nylon bearings, allowing for some play in the cutter.
#
Thanks everyone.

 

[david_bagshaw]

rattles like this can be problems with the flywheel drive plate.

 

[john_morris_uk]

Not sure if it helps but our Ambassador Rope cutter and feathering prop are totally silent (as far as I can tell).

 

[lpdsn]

My feathering prop & rope cutter are silent too. Not 100% sure of the brands as they came with the boat.

Only noise is a clunk when the engine is put into gear, no matter how gently it is done.

 

[heard28]

I have a Spurs cutter on my boat, and that has a couple of little plastic end-stops in the "wedge". I guess they are there to stop this kind of noise. Any chance that the Ambassador has the same, and they were dislodged during the prop-fitting exercise?

 

[GrahamM376]

Our Featherstream is quieter than the 2 blade fixed it replaced. When you refitted the rope cutter, did you allow room for the shaft to move forward under load? The wedge shouldn't be tight into the V block, it needs to have clearance.

 

[bluemoongaffer]

I fitted a feathering prop last year. My boat is small, long keel and a 14in prop. It was pretty noisy at anything other than low revs. After talking to Darglow, we thought it was most likely to be cavitation. This year, I removed some of the deadwood above and below the prop to give a minimum of 2 in clearance. Much quieter. The noise was rather like a clicking sound, worse when giving it a bit of welly from stationary. No vibration. I don't have a rope cutter. Great product and great service by the way.

 

[Neil_Y]

Feathering props should not be noisy, scissor type rope cutters can be. Check the cutter bearings, proximity to bearing carrier and also the shaft bearing. For soft drives where thrust is taken on engine mounts we have seen worst case shaft movement of 18.00mm total (fore and aft) so we recommend a min gap of 12.00mm to allow for 9.00mm movement and 3.00 remaining to allow water to exit the bearing.