Swivel Ball Stopper Plugs


Ian Shepherd
 

Have stripped my forestay swivel I found that both my ball stopper plugs were missing. Without these plugs the plastic balls will get a hammering as they pass the insertion hole. Amel tell me that these plugs are not available as a spare and that I should use some silicone to plug the holes. I am not happy with that solution as the balls need to have a smooth shaped surface to run over and silicone may well clog up the ball race.

My idea is to buy some 10mm nylon or wood dowelling and carefully file the plugs to the correct shape on the ball race side and to file a ridge in the other end so that it cannot twist once inserted. The ridge would sit in the slot in the carbon fibre sleeve.

I am disappointed that Amel do not sell an overhaul kit consisting of new ball bearings complete with a new sleeve and a new set of ball stopper plugs.

If anyone has another solution, please let me know.

Ian Shepherd SM2K 414 Crusader Cyprus


Ian Park
 

Ian
That is exactly what I did. But I went to a machine shop, left the swivel with them and they made a perfect stopper, shaped to the ball race and with the alignment ridge on the outside. Not sure what the plastic was - it was very hard and a perfect fit. I believe it was a plastic rod the correct diameter they started with.
I should have asked them to make a few spares but I didn’t think about it at the time.
That ridge is important if the stopper turns the swivel jams. I used a short plug at first but one bearing would catch on the edge of the hole, stop and jam it he rest. It has to be a match for the bearing groove.
Good luck.

Ian

Ocean Hobo SN96


greatketch@...
 

Ian,

The actual balls for the ball bearings are readily available.  They are a standard part. Mine were all in good shape, and got reassembled or I would measure them.  Measure carefully, and do not assume they are metric.  Many European manufacturers of moving rigging parts use 0.25 inch ball bearings. The cir-clips are also a standard size and widely available.  The plugs... of course not so much! 

I just had my swivel rebuilt.  The first cir-clip came out without a hitch, followed by the plug.  The second clip shattered when it was being removed, and left little corroded pieces of itself behind that made removing the plug a nightmare.  The cir-clips were replaced with stainless ones that will not have this problem.  

Like so many things, this is a compromise.  A higher risk of corrosion to the swivel body, but a lower risk of corrosion to an aluminum clip that can cause loss of the clips and plugs.  I have put a good coat of Lanocoat over the clips, and added the part to my routine inspection list.  Hopefully that, along with the part's location well above the normal salt spray zone, will keep things together and running smoothly.

An interesting piece of recent technical advice from Harkin about these plastic ball bearings in other applications.  They strongly suggest NOT lubricating them with the standard dry silicone lubricants-just keep them flushed with fresh water. The rational is the silicones can make the bearing race so slick that the balls start to slide instead of roll.  Then they get a flat spot, and things go down hill from there.  This was news to me, although it has the sound of truth to it.  

I haven't decided yet if I will stop putting dry lube on parts like this.  

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL, USA