Ambassador Rope Stripper - excessive clicking

[robmcg]

Last year we changed the prop and the shaft on the boat. We retained the Ambassador Rope stripper from the old shaft. Now we get an excessive clicking noise from the stripper as it hits the striker plate. This is far more pronounced than with the previous shaft/prop and is audible above the engine. In fact, if you rev the engine to cruising revs, the noise is unbearable and sounds like the whole drivetrain is rattling itself off. Boat is currently ashore and the rope stripper is properly secured to the shaft. Any thoughts on why the noise level is now so bad? Is it easier to just switch to a single piece shaft knife or is there something that can be adjusted on the stripper to minimise the noise it makes against the striker plate? All thoughts most welcome .

 

[Poey50]

I had some problems with the Stripper not rotating freely. It was caused by me tightening the machine screws in the wrong order and therefore misaligning one part of it.

 

[Tranona]

Check that the cutter is positioned correctly in relation to the striker block. The tongue should be 6mm away from the back of the slot. Do you have the anti rattle plates fitted? Check the bearing rings are not worn.

This is what it should all look like.

 

[vyv_cox]

If I remember correctly this is a sign that PTFE spacers are worn and need to be replaced.

 

[Tranona]

Servicing instructions here

ropestripper.com/documents/servicing-am5-10-15.pdf

 

[Martin_J]

And by the word 'bearings' in their instructions, they do just mean the plastic spacers... nothing like we commonly use the word bearings for.

 

[SteveG]

If all other suggestions fail, beware that the striker block is not too close to the cutlass bearing mount/P bracket. It is adjusted with the 3 allen head grub screws and the mounting bolts. Too close and it can foul the socket head screws clamping the rotor to the shaft. You would end up with the edges of the socket screws rounded off a bit on the outside, hence a loud clicking noise as the heads are worn down. I speak from experience!!

 

[robmcg]

I have checked the installation and it looks OK to me (thanks for the photo Tranona). How do you assess if the plastic bearings need replacing? They are there and visible but I don't know if they are worn beyond their useful life?
When you move the shaft it does make a very loud clicking between the fixed blade and striker plate something akin to a set of wind up comedy teeth .

 

[peter gibbs]

Last year we changed the prop and the shaft on the boat. We retained the Ambassador Rope stripper from the old shaft. Now we get an excessive clicking noise from the stripper as it hits the striker plate. This is far more pronounced than with the previous shaft/prop and is audible above the engine. In fact, if you rev the engine to cruising revs, the noise is unbearable and sounds like the whole drivetrain is rattling itself off. Boat is currently ashore and the rope stripper is properly secured to the shaft. Any thoughts on why the noise level is now so bad? Is it easier to just switch to a single piece shaft knife or is there something that can be adjusted on the stripper to minimise the noise it makes against the striker plate? All thoughts most welcome .

As a long term Ambassador user i have to advise you it is not designed to strike the static plate. There has to be a small clearance. If this has been eliminated by wear on the plastic spacers, they must be replaced. If the cutters engage through lack of proper spacing, wear will intensify and it could lock.

 

[PeterBoater]

I have checked the installation and it looks OK to me (thanks for the photo Tranona). How do you assess if the plastic bearings need replacing? They are there and visible but I don't know if they are worn beyond their useful life?
When you move the shaft it does make a very loud clicking between the fixed blade and striker plate something akin to a set of wind up comedy teeth .

Did you not read the link helpfully supplied to you in post #5?

 

[Refueler]

If I remember correctly this is a sign that PTFE spacers are worn and need to be replaced.

Correct.

 

[robmcg]

Update - I have ordered the service kit for the stripper. As it will be disassembled to put the new bearings in, I will see if there is anything else amiss with the installation. Fortunately, the shaft is coming out in the next few days anyway (unrelated to the stripper noise) so it's a good opportunity to check over everything.

 

[PeterBoater]

While you've got the thing apart, clean up/polish the metal surfaces that come in contact with the bearings. Don't take off any metal, just remove any roughness that might abrade the new bearings. If with the new bearings it still fails the tolerance specified in the manual (as per the link above), you might be looking at a new fixed cutter blade if it has partially worn away; available as a spare part. Sit down before you see the price! I spoke to the Ambassador bloke a couple of years back about the wear rate of the bearings. He said it varies a huge amount with location; on the South Coast they might last years but on the East Coast they might only last a year or two. All depends on the grit etc in the water.

 

[robmcg]

Further update. The service kit arrived for the rope stripper. You don't get much for nearly £50 delivered . Anyway, took the stripper off and one of the plastic bearings was broken. They both showed evidence of wear and indeed when turned by hand off the shaft there were two points where some binding of the bearings could be felt. Cleaned up the surfaces in contact with the bearings and reassembled. No tight spots now. Shaft is out at the moment for an unrelated job so hopefully this will have cured whatever was causing the excessive chattering. No real visible wear or anything untoward discovered whilst it was in bits.
Thanks to those who have contributed. I have followed all your advice so now have my fingers crossed .