There's something up with my shaft..

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AlistairC

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There\'s something up with my shaft..

Its bent! oh no!
I'll get her lifted this week.
Anyone had to sort this little problem out before?
 
Re: There\'s something up with my shaft..

You should see a Dr , might be able to do something about the bend . More than likely prescribe viagra for the lifting .
 
Re: There\'s something up with my shaft..

[ QUOTE ]
Its bent! oh no!
I'll get her lifted this week.
Anyone had to sort this little problem out before?

[/ QUOTE ]Been there and 'tis not funny. Might be cheaper to have a new shaft made than try to straighten the old one. I doubt if there are many (if any) places left with the skilled people to straighten a bent shaft and get it right. I had one straightened a couple of years ago, cost more than a new one at the end of the day. First attempt looked OK but too much vibration, another lift out and chocking up and shaft out. Still slightly out of true, one more try same (another lift out) new shaft made and fitted no problem. OK the CO didn't charge for the second attempt or the new shaft but I still had 3 lifts to pay for and I missed many good weekends sailing.

If it happens again I will go for a replacement first time, not a straightening job,


Tom

Tom
 
Re: There\'s something up with my shaft..

If it's bent behind the 'P' bracket where the prop' is attached it's a DIY job to straighten.
All you need is a hydraulic jack, a dial gauge and some patience.
I have straightened several shafts cold by turning them until the bed is downwards and then jacking up against the weight of the boat. Checking at each attempt with the dial gauge to see whether the shaft is running straight.
Once you're within 5 thou' you won't notice any further problems.
 
Re: There\'s something up with my shaft..

I think its worse than that, the wobble is visible on the stern gland, I think I'm going to go for a new shaft as I was in the market for a new prop but didnt get around to it last winter.
 
Re: There\'s something up with my shaft..

Tallon, thanks for your advice, I will definately go for new, as at least then its one less thing to replace!
 
Re: There\'s something up with my shaft..

Very roughly, how much am I looking at? Its a 28ft boat, so probably about 1.5 to 2m long I guess. (the shaft not the boat - my conversions arent that bad /forums/images/graemlins/smile.gif
 
Re: There\'s something up with my shaft..

Couldn't say exactly but I would guess less than 80 beer tokens including the machining of the taper and threads for a 2m X 25mm shaft in 316 or less then 110BTs in Monel. Depends on what length of material your supplier has to buy and how much he charges for the lathe work. In reality the material costs are negligible compared to labour costs. Top line I would not expect any more then 150 BTs.

Rather than letting some guy loose with a jack, take the bent one to a shaft specialist and see what they qoute for straightening. I don't fancy having to replace stern glands or cutlass bearings every year becoust the shaft is a few thou out of alignment,

Tom
 
Re: There\'s something up with my shaft..

Couldn't say exactly but I would guess less than 80 beer tokens including the machining of the taper and threads for a 2m X 25mm shaft in 316 or less then 110BTs in Monel. Depends on what length of material your supplier has to buy and how much he charges for the lathe work. In reality the material costs are negligible compared to labour costs. Top line I would not expect any more then 150 BTs.

Rather than letting some guy loose with a jack, take the bent one to a shaft specialist and see what they qoute for straightening. I wouldn't fancy having to replace stern glands or cutlass bearings every year because the shaft is a few thou out of alignment,

Tom
 
Re: There\'s something up with my shaft..

Aah thats not too bad, for that money its not worth trying to fix it, after all the lift out and back in would wipe out any savings if I had to "have another go at it"
 
Re: There\'s something up with my shaft..

[ QUOTE ]
Aah thats not too bad, for that money its not worth trying to fix it, after all the lift out and back in would wipe out any savings if I had to "have another go at it"

[/ QUOTE ]Check around and see what is available locally. When one adds up the costs of a lift out (in my case 3 times) it might be better to go for a new one.

Tom
 
Re: There\'s something up with my shaft..

From your description Alistair I'd not consider straightening - certainly not in situ let alone using specialists with the right presses etc. The material seems to have been quite severly strained 'plastically' and cold rebending to straighten - even if it can be achieved - leaves you with an unhealthy shaft less able to cope and liable to re-deformation. I guess you know the cause and can eliminate/avoid in future?
 
Re: There\'s something up with my shaft..

yes I think the opinion seems quite unanimous. New shaft.

as I mentioned, i was thinking of a new prop, so it might as well go on a brand new shaft rather than a worn one.

I'm either going to have to find an engineer or start the learning curve - i'm better with electronics really /forums/images/graemlins/smile.gif
 
Re: There\'s something up with my shaft..

I had a new shaft last easter, 53 inches long 1.25 inches Dia.Stainless steel (316) machined with taper 2 keyways thread on one end. Also a new cast bronze nut The whole cabodle £70 . Roy Willaby Unit 3 Station Rd, Stocton, Southam, Rugby CV47 8HS. 01926-814598. Super job, Roy is very knowledgable.
 
Re: There\'s something up with my shaft..

I had a new shaft this season 53 inches long 1.25 inches dia. Machined 1 taper, 2 keyways, thread cut 1 end, plus new cast bronze nut. The whole caboodle £70.
Roy Willaby Unit 3 Station Rd, Stocton Southam, Rugby CV47 8HS 01926-814598. I was very pleased with job Roy is very knowledgable. If it suits you to visit in person get detailed directions because this industrial site is up a farm track out in the sticks. I had trouble even with the sat nav
 
Re: There\'s something up with my shaft..

Have no problem with shaft even though bent a bit to stbd. Problem seems to be with housing. Swmbo just downed her 3rd vodka and coke and is not likely to wake up to see if it fits.
 
Re: There\'s something up with my shaft..

Slow down. How do you know your shaft is bent?

Did your prop pick up something? Has it hit a floating log? If you roll it along a known flat surface does it roll straight?

Have you considered other problems with a 'wobble' at the stern gland.

I would be thinking of basic things like engine alignment, or old engine feet first.

'something up with my shaft' is not enough evidence.

Donald
 
Re: There\'s something up with my shaft..

I hit a stick/small log last time I was out.

I guess it could be engine alignment, maybe I should get an engineer out before I pay to have her lifted. I've never done any aligning before.
 
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