New prop bore.

bigman1

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Hi folks,
I recently posted about the state of my 17x13 prop. and the forum consensus was that it was dezincified.Well i have taken delivery of a new prop. only problem is that there is 18 thou. difference in the bores,the new prop.is the big one (1 to 12 taper) so with that margin i guess the new one won't fit ( i have still to go to boat to try it) so with the belief that new one will rattle on the shaft taper, what to do?.
I could make a new one if it will fit in between lathe centres ( 24") have still to measure it or brass shims or several coats of epoxy resin?
When i said a new one i meant a new shaft or shim or resin in prop bore?. If i can't get 316 stainless bar to fit in lathe i could braze the and machine the taper, all a hell of a bother well i suppose that's boats. What do the forum handy folks think?. Ronnie.
 
Hi folks,
I recently posted about the state of my 17x13 prop. and the forum consensus was that it was dezincified.Well i have taken delivery of a new prop. only problem is that there is 18 thou. difference in the bores,the new prop.is the big one (1 to 12 taper) so with that margin i guess the new one won't fit ( i have still to go to boat to try it) so with the belief that new one will rattle on the shaft taper, what to do?.
I could make a new one if it will fit in between lathe centres ( 24") have still to measure it or brass shims or several coats of epoxy resin?
When i said a new one i meant a new shaft or shim or resin in prop bore?. If i can't get 316 stainless bar to fit in lathe i could braze the and machine the taper, all a hell of a bother well i suppose that's boats. What do the forum handy folks think?. Ronnie.
Am I missing something or does a 12:1 taper and an 18 thou oversize mean that the prop just sits ~ 2 tenths of an inch further forward on the shaft ? Probably not a big issue if so but maybe there is somthing I have not understood here ?

Boo2
 
Seems like you have the wrong prop. The tapers are usually different between Imperial and metric shafts. Measure the diameter of your shaft accurately - there are minor differences between comparable imperial and metric so you need to be VERY accurate. You can also measure the taper on your shaft. Then buy the correct prop to fit the shaft you have. Do not attempt to "bodge" it. Props are available machined correctly so no reason to try and make mismatched components fit.

BTW if you try to make a shaft to fit the prop you will end up having to change the coupling, shaft seal and outer bearing to suit - so better to get the right prop.
 
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