New prop shaft needed....any suggestions?

[oldharry]

Not quite correct. The stainless bar we used to make for shafting (sold a lot to Greece where they often have pumps at the bottom of a deep well) is produced to a much tighter straightness tolerance than the everday steel stockist material. Obviously less of an issue the shorter the shaft but I would be cautious of using a general engineer who doesnt normally work with stainless or make long shafts.

Quite right: researching a new shaft for my last boat, I tried several local engineering shops. At least half of them would not touch it at all - "awkward 'one off' job sir", some were worried about cutting the taper correctly. Others quoted prices ranging from £100 - £350 (shaft about 1.3m length 25mmdia). Eventually got one from Lancing Marine for about £80.

 

[Leighb]

Also check out your local Hydraulic ram repairer, they often replace the long shats in rams when they are damaged or get bent.

Scrap yards also see a few of the above so also worth checking.

The end result is still enough to make up a solid rudder stock.

An interesting suggestion, but I think hydraulic rams are pretty rare in the UK these days. There used to be one on the stream in our garden years ago which supplied water to the Hall a mile away.

 

[JimC]

www.crowthermarine.co.uk

 

[Deleted member 36384]

Ground 316 Shaft Price - Scotland, Firth of Clyde

I am in Scotland. 2009 Invoice price for a 316 Stainless Ground Bar, machined taper, nut and key £489.70. The shaft is just over 1 1/4" diameter and about 1 .25m long. I probably could have shopped around and got a better price but that was not possible at the time.

The money is in grinding true which I understand takes a bit more machine time than turning a taper and milling a slot. The vibration is very low on my boat which I put down in part to the trueness of the shaft.

 

[ianat182]

When I had a new shaft supplied by Hamble Propellors at Bursledon, the shaft was slotted and threaded and a nut provided. They did not drill the hole for the split pin in the shaft which I actually did later using cobalt drill and lots of patience. They said that they couldn't know where the position would be when the washer and nut were tightened up.After wearing out several'titanium coated drills I searched around for the cobalt one which did the job easily. They had no trouble with Imperial shaft diameter,or Woodruff key .

ianat182

 

[macd]

Would recommend them as well.

Another vote for T Norris. Excellent service at a good price.

 

[doug748]

Further to ianat182's problem of drilling for a split pin.
Ask if they can supply a tab washer, this fits into its own notch or groove in the shaft and you knock it over the nut when you tighten the prop up. Very easy to do.

 

[brianhumber]

Rams

An interesting suggestion, but I think hydraulic rams are pretty rare in the UK these days. There used to be one on the stream in our garden years ago which supplied water to the Hall a mile away.

Think he is referring to hydraulic oil rams as in power applications not the water lifting types.

Replaced the metre plus long ram on Ronhilda's lifting keel some years ago and new 316 SS ram plus machining, plus seals, fitted and tested/certified to 4,000 psi was £150 some years ago. Firm was on the A2 and did all the rams for the doors etc on the cross channel ferrys at Dover. Kept the old shaft and still have it with a view to turning it into a new prop shaft if ever needed.
Brian