What bearings for anchor roller?

[GHA]

Looking at fitting bearings to the anchor roller, not so much for the chain (though might anyway..) but the snubber is onboard then goes over the other roller then soft shackled into the chain. 95% of the time hardly moves but a decent onshore for a few days means constant pitching the snubber moving a good few feet every few seconds for sometimes days so a lot of movement, not too bad yet but will certainly wear with the boat always on the hook. .
Idea is get the bearings then get a back street fabricator to rebate out the roller, think they are acetol with 16mm axle bolt.

So what bearings would suit?

Something like these? >
SMB Bearings


TIA

 

[rogerthebodger]

My bow rollers are made from Visconte which is a water lubricated bearing in itself.

I use the same material for rubber bearings and prop shaft bearings

Stainless steel ball bearings could be used but I would not use then in a bow roller

I do use stainless steel ball bearings in my mast head and foot halyard sheaves as they are better protected

 

[B27]

Why not deal with the problem at source?
Move the snubber 'off board', In front of the boat.

 

[GHA]

Why not deal with the problem at source?
Move the snubber 'off board', In front of the boat.

Bad idea, it's onboard for many very good reasons which would be better discussed in another thread, this thread which about materials, you could start your own thread if you would like to discuss more.

 

[GHA]

My bow rollers are made from Visconte which is a water lubricated bearing in itself.

I use the same material for rubber bearings and prop shaft bearings

Stainless steel ball bearings could be used but I would not use then in a bow roller

I do use stainless steel ball bearings in my mast head and foot halyard sheaves as they are better protected

Good idea! No immediate google to a uk supplier. Back in the day working in theatre we'd use Nylotron or molybdenum impregnated nylon, 1m bar of that would probably do, make up a load of spares to replace if & when needed.

RS used to do so much more materials it seems!!

Nylatron seems easy to get, sounds the way to go & handy to have a bit onboard anyway, sorted - thanks Roger!

 

[Dogone]

Good idea! No immediate google to a uk supplier. Back in the day working in theatre we'd use Nylotron or molybdenum impregnated nylon, 1m bar of that would probably do, make up a load of spares to replace if & when needed.

RS used to do so much more materials it seems!!

Nylatron seems easy to get, sounds the way to go & handy to have a bit onboard anyway, sorted - thanks Roger!

Older than that is Oilite. Oil impregnated bronze usually used as a sleeved plain bearing insert. Bronze being good, strong,, wear resistant and corrosion proof boaty stuff it might be suitable. Check strength too.

 

[GHA]

Older than that is Oilite. Oil impregnated bronze usually used as a sleeved plain bearing insert. Bronze being good, strong,, wear resistant and corrosion proof boaty stuff it might be suitable. Check strength too.

Looks nice.

Looks expensive compared to some nylatron bar!

 

[Tranona]

Are you sure you have a (potential) problem? If the roller is an acetal such as Delrin it is low friction
google.com/search?q=delrin+material+properties&rlz=1C1VDKB_en-GBGB1067GB1067&oq=&gs_lcrp=EgZjaHJvbWUqCQgBEEUYOxjCAzIJCAAQRRg7GMIDMgkIARBFGDsYwgMyCQgCEEUYOxjCAzIJCAMQRRg7GMIDMgkIBBBFGDsYwgMyCQgFEEUYOxjCAzIJCAYQRRg7GMIDMgkIBxBFGDsYwgPSAQk2NjA0NGowajeoAgiwAgE&sourceid=chrome&ie=UTF-8

 

[GHA]

Are you sure you have a (potential) problem? If the roller is an acetal such as Delrin it is low friction
google.com/search?q=delrin+material+properties&rlz=1C1VDKB_en-GBGB1067GB1067&oq=&gs_lcrp=EgZjaHJvbWUqCQgBEEUYOxjCAzIJCAAQRRg7GMIDMgkIARBFGDsYwgMyCQgCEEUYOxjCAzIJCAMQRRg7GMIDMgkIBBBFGDsYwgMyCQgFEEUYOxjCAzIJCAYQRRg7GMIDMgkIBxBFGDsYwgPSAQk2NjA0NGowajeoAgiwAgE&sourceid=chrome&ie=UTF-8

In the real world yes.
Slight wear has started, spare bearings separate from the roller which can be swapped out are, imho, a good idea & cost little.
From the perspective of a cruising boat living very far from western shops.

 

[geem]

My rope snubber roller is stainless steel. No wear

 

[GHA]

My rope snubber roller is stainless steel. No wear

Posh git!

I've a short length of 12mm dyneema going over the spare bow roller (just cos there was a bit in a locker as much as anything) soft shackled into the chain so it can chafe away to next to nothing & still hold. not that it should but the real world can bite yer bum sometimes at 3am when it's blowing up.

Vague head CAD drawings of mounting sheaves semi permanently on deck for the nylon snubber instead of pulley blocks so a length of bearing material may well come in handy. And a little dusty back street machine shop one day to turn it all up for cost of an airport coffee or 2

 

[vyv_cox]

Both my bow rollers were turned from acetal. Not sure how long ago, ten years? No obvious wear. Acetal is a widely used self lubricating polymer that is just about ideal for the job. Nylon swells considerably in water, up to 11% for some grades.

 

[rogerthebodger]

Good idea! No immediate google to a uk supplier. Back in the day working in theatre we'd use Nylotron or molybdenum impregnated nylon, 1m bar of that would probably do, make up a load of spares to replace if & when needed.

RS used to do so much more materials it seems!!

Nylatron seems easy to get, sounds the way to go & handy to have a bit onboard anyway, sorted - thanks Roger!

Vesconite - world-leading manufacturer of low-friction low-wear bearings

you will find a UK phone number at the bottom of the above link, or you could E Mail /phone my supplier

Tip you could ask for a sample and make one from the sample

 

[Aja]

Starboard roller for chain is bronze. Snubber is nylon rode passing through a piece of pvc hose over an acetal roller. This has a small worn area maybe to a depth of 2mm but roller so cheap I had a spare made at the same time. Maybe overthinking things?

Admittedly I'm not at anchor every night for days on end, but works for me

 

[Tranona]

Vesconite - world-leading manufacturer of low-friction low-wear bearings

you will find a UK phone number at the bottom of the above link, or you could E Mail /phone my supplier

Tip you could ask for a sample and make one from the sample

Although there is a phone number I don't think there is any stock held in the UK now. They used to have an arrangement with Bartholomews in Southampton, but that does not seem to be operating now.

 

[colhel]

I don't know what tolerances on an axle bolt but if the hole in the acetal was a good slide fit it should last ages. Another solution is to get a 16mm ID "oilite" sleeve and machine the roller so it's a tight fit in that.

I tried posting a link to a suitable "oilite bearing" but the forum wouldn't have it for some reason


Oil Filled Bronze Flange Bushes: Oilite Oil Filled Bronze Flanged Bushes

 

[B27]

You can get various plastic bushes which might be OK, cheap and replaceable, but actually, the anchor roller can be quite a high stress component. The 'fretting' action is perhaps exactly wrong for a stainless ball race?
You should wonder what the sides of the stemhead assembly will be doing to the rode, as in the real world, the anchor is not always dead ahead of the yacht.
Igus is one brand of bush to look at.

 

[Zing]

You can get various plastic bushes which might be OK, cheap and replaceable, but actually, the anchor roller can be quite a high stress component. The 'fretting' action is perhaps exactly wrong for a stainless ball race?
You should wonder what the sides of the stemhead assembly will be doing to the rode, as in the real world, the anchor is not always dead ahead of the yacht.
Igus is one brand of bush to look at.

I’ve used Igus bearings on machinery I designed. Worked well, but they are weak. Unlikely to be suitable in this application I think unless the design accommodates that issue and I believe that will be very hard to do.

 

[B27]

I’ve used Igus bearings on machinery I designed. Worked well, but they are weak. Unlikely to be suitable in this application I think unless the design accommodates that issue and I believe that will be very hard to do.

you're probably right.
Any plastic less rigid than the acetal will probably deform too much under load?
When the boat is affected by chop or breeze, the loads may not be small.
Perhaps a smear of silicone grease would help?
If it's wet, any bearing material harder than acetal might wear the stainless axle, because that depends on forming an oxide layer.

Avoiding fretting movement at the stemhead is much quieter for one thing!

 

[noelex]

We use a very similar set up.

We had around 3000 nights at anchor on our previous yacht on a plain bearing, and there was minimal wear. Our current boat has around 2000 nights at anchor with a similar result. However, the friction of the bow roller under load effects the maximum pulling power of the windlass. The force often has a 90° change of direction. I think installing low friction bearings will have significant advantages, so your project will have some worthwhile and practical benefits.

One principle that helps both wear on the bearing and the overall load on the windlass is to install a large bow roller where possible.

Below is a photo of our current bow roller.

Bigger is better for most anchoring equipment .