3 blade propeller

[Maudesmaster]

Anybody sitting near a 3 blade propeller 1”1/2 bore and can measure the diameter of the boss boat side 

I’m making a puller and need to know distance from shaft centre to outside boss for threaded studding 

have new prop but on boat in Penkridge I’m in Canterbury waiting hip op 

lost the fag packet with dimensions on 

thank you 

[David Mack]

I suspect it will vary from one prop to another, so somebody else's measurement may not be right for yours.

[Maudesmaster]

I’m guessing for 1”1/2 shaft all going to be about the same amount of meat to where the blade begins 

[MtB]

3 hours ago, Maudesmaster said:

Anybody sitting near a 3 blade propeller 1”1/2 bore and can measure the diameter of the boss boat side 

I’m making a puller and need to know distance from shaft centre to outside boss for threaded studding 

have new prop but on boat in Penkridge I’m in Canterbury waiting hip op 

lost the fag packet with dimensions on 

thank you 

 

 

I have quite a few propellers lying around in my hovel, within a few feet of me. I'll have a measure. 

 

 

First prop, a Crowther prop made for my Kelvin K1 is 71.0mm outside diameter at the fat end of the boss.

 

 

 

 

Second prop is 66mm outside diameter. This is off a lifeboat that had a Lister HRW2 in it. It is actually bigger in diameter at the centre than at either end. Peaking at about 70mm I'd guess but my vernier won't reach. 

 

Third prop is of uncertain origin and the boss is really bulbous in shape. The machined flat area at the end for the nut and washer to bear on is 58.8mm diameter but the centre of the boss is closer to 85mm.

[Slim]

1 hour ago, MtB said:

 

 

I have quite a few propellers lying around in my hovel, within a few feet of me. I'll have a measure. 

 

 

First prop, a Crowther prop made for my Kelvin K1 is 71.0mm outside diameter at the fat end of the boss.

 

 

 

 

Second prop is 66mm outside diameter. This is off a lifeboat that had a Lister HRW2 in it. It is actually bigger in diameter at the centre than at either end. Peaking at about 70mm I'd guess but my vernier won't reach. 

 

Third prop is of uncertain origin and the boss is really bulbous in shape. The machined flat area at the end for the nut and washer to bear on is 58.8mm diameter but the centre of the boss is closer to 85mm.

😀And I get concerned about a bit of dust.

OP, Good luck with the hip op

 

[Maudesmaster]

Thank you I thought it was 2 1/2” from memory but drilling back plate it looked small 🤞🏼It’ll be about right 

[john.k]

propellors are bronze ,usually ,shafts stainless 304 0r 316 ......heat the prop and it will come off a lot easier than a cold pull...........Id also recommend a thread  protector if pulling hard ........if a key has sheared and the prop turned on the taper ,it a job and a half to get it off. .......use a brass/bronze nut and split pin ...stainless on stainless will seize hard ,and you will have to split the nut to get it off without ruining the shaft thread.

Edited April 6 by john.k

[Maudesmaster]

Thank you but boat in water I changed it from 21”-18 pitch to 21”-21 pitch 18 months ago heating prop on slipway and replaced whilst in the water  but that got badly bent blades so was going to try home made puller to drop it off again in the water 

I had a date 5th March to haul out but day came and went waited for new date but very allusive so just thought give it a go at least until new date comes up but have to be after Hip Op now 

 

Edited April 6 by Maudesmaster

[john.k]

Its amazing what the propellor fixers can fix on a damaged prop .

[Maudesmaster]

Yes I make you right but takes 7/8 weeks to cast a new and 4 weeks to repair so now I’ll have a spare after one on boat now repaired 👍🖖