Bent prop shaft

[Restoration man]

Hi I’ve got a grp storebro biscay 31 that im fixing up, there was Evidence of a repair by the p bracket on the starboard side that I wasn’t happy with so I’ve pulled both shafts and removed both p brackets and had the props checked out and balanced , I’ve had local engineering company spin the shafts up in his lathe And sure enough one is bent I can’t be sure it’s the one on the damaged side as I forget to mark it when I took them out ,he put a clock on it and it’s 2.5 mm out in the middle and 2mm out by the p bracket I’m assuming this is way to much ? The props are like 20” in diameter and the boat should do maximum 25 knots or so I’ve been told on the storebro site , if this is way out like I’m thinking has anyone had a shaft Straightened its 40mm ? Or do need to get new one made ? I don’t know how bad it must have shook prior to be getting the boat as foolishly i bought it without a Sea trail as it was bought as a fixer upper , also I’ve got video of it spinning in the lathe If anyone knows how to post it ?
thanks Nick

 

[kashurst]

If a shaft is even slightly bent you will know!
Shafts can be straightened, I had one repaired years ago, sorry no help can't remember who did it. I think it was a firm in Sheffield. Hopefully someone will be along soon with a name/number. Worst case a new one.

 

[longjohnsilver]

Give C&O Engineering in Newton Abbot a call 01626 367782. If it’s too far away they may be able to suggest somewhere more local to you.
PS A lovely boat, well worth the effort of fixing.

 

[Bristolfashion]

Hamble propellors did my prop & straightened my shaft - excellent work.

 

[Kawasaki]

'T Norris Marine'
Islworth middlesex
Bung em yer bent one and they with fix or fabricate a new un

 

[Restoration man]

Thanks for the reply’s it’s good to know it can be fixed, I will contact those names and see what they say , I will report back when I get it done and let the forum know how much it cost

 

[Restoration man]

Give C&O Engineering in Newton Abbot a call 01626 367782. If it’s too far away they may be able to suggest somewhere more local to you.
PS A lovely boat, well worth the effort of fixing.

thanks longjohnsilver , i do have to keep reminding myself it’s worth the effort, they do get you down at times , one day this boat will stop surprising me , but if I’m honest the shaft wasn’t much of a surprise , better to do i right first time I suppose

 

[oldgit]

Is there any wear or corrosion on the shaft, either around the stern gland or " P" bracket.
Compare the prices of new shaft vs straighting first.
Also worth checking that those " P" brackets are true, pointless getting a new shaft or having the the old one straightened if the bracket is not 100%
Uneven wear on the cutlass is givaway.

 

[Restoration man]

Is there any wear or corrosion on the shaft, either around the stern gland or " P" bracket.
Compare the prices of new shaft vs straighting first.
Also worth checking that those " P" brackets are true, pointless getting a new shaft or having the the old one straightened if the bracket is not 100%
Uneven wear on the cutlass is givaway.

There is no real wear on the shafts, at either end , but both cutless bearings we’re completely shot ,
when I got the boat there was a thin plywood packer under the one p bracket , I assume a crude way to get the shaft re aligned after the accident bent the shaf , also all the engines mounts are seized up ,
im Assuming the engines are also badly out of alignment , p brackets look ok by eye ,I’ve goto do some glass work under the one p bracket
to fix the crack in the hull so even if one of the p brackets is fractionally bent I’m hoping I can fair Under the bracket if absolutely necessary to pull it back into line , I’m planning on dry fitting everything once the glasswork is done and resetting the alignment starting with the only bit I can’t change that’s the position of the stern tube both other ends can be altered if needed , and hopefully re align everything ,fingers crossed I should be able to pull it back into alignment ???,

 

[Bilgediver]

I’ve had local engineering company spin the shafts up in his lathe And sure enough one is bent I can’t be sure it’s the one on the damaged side as I forget to mark it when I took them out ,he put a clock on it and it’s 2.5 mm out in the middle and 2mm out by the p bracket I’m assuming this is way to much ?

If I lived on the Boon Docks in some far off place then I would certainly attempt to straighten it. Just need a big enough hydraulic press and accessories, Just might take more than a minute or two. However the measurements you give suggest that it might not be so simple in the case of yours and maybe why the engineering company did not offer to do this.

Contact Norris for an indicative price to machine one.


T.Norris Marine. Supplier of Propellers, Stern Gear & Marine Equipment

 

[oldgit]

Most boaty areas,especially those with any commercial boats will have a engineering shop capable of turning up a shaft.
Have had shaft work done both by Norris and local shop.
The local shop did a faster job ,was cheaper and as most workshops will refuse ouright to turn up a shaft without seeing you old one first, I also saved a week and about £100 pounds on shipping costs.
Norris were 100% regards quality but they did have to refund money when they miscalculated the bill, it was only when I bothered to query the total , when the overcharging came to light.
They were not overgracious giving the refund either.

 

[Restoration man]

I’ve found place local to me that specialise in Precision Straightening, ive rung them told them the length and diameter of the shaft and that’s its stainless and that is bot prop shaft , they say it shouldn’t be problem to sort it out and it will be there standard lowest charge of £52 +vat to Straighten it, on there site there is photos of them Straightening hydraulic pistons im Sure they would have to be very straight , taking it to them today so I will report back when I’ve had it done this is the place it’s in Wolverhampton metal straightening services | west midlands | John Macnab Services Ltd

 

[Andrew M]

What a find ! Looks like a superb company , well done and hope they can sort the shaft.

 

[Restoration man]

feedback time , took the shafts to the Straighteners I’ve put some videos of before and after , 1st video is at the engineering company who stuck it in his lathe watch it to the end of the video when he turns the speed up ?, 2nd video is at Straighteners turned out it was bent 3 mm , 3rd and 4th videos are of the finished job I think he said they were accurate to within 5 thou , I had them check the other shaft while I was there and that was also bent but not as bad as the other one , they charged me £72 + vat to do both , saved me fortune great company ,he said he could have fixed it even if it had a 30mm bend

Prop shaft before Straightening 1

Prop shaft before Straightening 2

 

[DavidJ]

Great job
They clearly don’t understand marine market pricing