Split pins through the prop Shaft

[Guest]

After getting the boat lifted out to get the prop refitter with tab washer and nut what is the general consensus on the fitting of split pins behind the nut?

 

[Guest]

If the hub taper and shaft taper are matched and the tab washer is correctly fitted , putting a split pin in is a total waste of time and effort.

 

[Guest]

A common arrangement is to use a crown nut, with a split pin through. This is more secure than a split pin behind a conventional nut. Crown nuts are available for most shaft sizes.

 

[Guest]

In bronze? Where from? I'd much prefer to use a crown nut than the wretched pieced nut on my prop shaft.

 

[Guest]

If tapers are fine then there's really no need,,,unless you are a belt and bracers man

 

[Guest]

"Belt and Braces" is very wise. But you do not need a tab-washer and a split-pin, as well as a proper fitting taper. A split-pin through a castelated (crown) nut is the more common arrangement.

 

[Guest]

Agree

It's a very brave man who relies only on the taper and nut tightness, particularly because the nut should not be excessively tight on a taper fitting. Castellated nut and split pin is my option. Never forget Murphy: "What can go wrong will go wrong".

 

[Guest]

Castle nuts.

Sorry, I should have said 'castle' nuts. You should be able to get a suitable one through your local yacht yard, but I got one from RSR in Hythe (Kent) - see http://www.rsrfasteners.co.uk/home.htm

You need to be a bit careful about the metal it's made of, I think it should be the same as the shaft, but your yard will advise.

 

[Guest]

If the split pin (and prefgerably castel nut) are not necessary, then why are they nearly always fitted?

I would not rely on a tab washer either - they can fail.

Split pin and nut = secure propellor. An unsecured nut is just that, and can (will) release itself sooner or later.

 

[Guest]

Thankyou as this seems to back up what I have been told buy yards!

 

[Guest]

Castle nuts.

Sorry, I should have said 'castle' nuts. You should be able to get a suitable one through your local yacht yard, but I got one from RSR in Hythe (Kent) - see http://www.rsrfasteners.co.uk/home.htm

You need to be a bit careful about the metal it's made of, I think it should be the same as the shaft, but your yard will advise.

 

[Guest]

The trouble with tab washers is that the always fit into the keyway in the prop. If you have a problem with the key - e.g. the previous owner fitted a brass key that dissolved away on my boat - then the tab washer is worse than useless. It forces the nut undone if the prop slips on the taper, as happened to me when the prop hit something underwater. There is a lot to be said for a split pin. At least the nut and prop are unlikely to fall off. Fortunately mine didn't. I was able to beach the boat soon after hearing a strange rattling noise from the prop shaft area! The key was like a miniature picture frame - all corners and no middle!

 

[Guest]

The split pin is there to stop the nut coming undone, which as Vye says, WILL happen sooner or later!! The taper on the shaft / prop distributes the load under power. ALSO - the split pin should be the same material as the shaft - prop - nut etc. In the 'old days' a yard would cast all the fittings for a boat at the same time - that way the content of the alloy was the same and there was less electrolysis

 

[Guest]

ROFL Even your wrong Andrew .. Its CASTELATED! NM

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