Propeller shaft prep for prop

[RT Firefly]

Hiya,
** Stub sitting in strut screws onto shaft and is bolted in place to prop.* Once assembled now "solid" propshaft is supported by strut aft of prop unlike smaller vessels where shaft is supported by strut forward of prop.

 

[Nomad Willy]

OK this is like a fun game.
My guess.
The flange (just below the guys left collar(in the pic)) has holes that match the drilled and taped holes in the prop hub. One simply tightens the ss nut to the correct torque and then rotates a bit to the closest holes that align and then install and torque the hex head machine screws through the flange and into the propeller hub.
Power went out and my msg is still here wow.
RT, that should'nt work. As the power is applied the engine, gearbox, shaft and prop needs to move fwd a bit against the engine mounts. That taper on the nut would introduce a lot of slop but of course one could have a Aqua Drive or Python Drive or some other thrust bearing but even the hull flexing could unload a tapered bearing there.





-- Edited by nomadwilly on Monday 27th of December 2010 11:20:36 PM

 

[RickB]

RT Firefly wrote:

Hiya,
Stub sitting in strut screws onto shaft and is bolted in place to prop.* Once assembled now "solid" propshaft is supported by strut aft of prop unlike smaller vessels where shaft is supported by strut forward of prop.

RTF wins the ceegar!* It really is an unusual arrangement. It was designed to provide a cleaner inflow to the propeller. How much difference that bit of an efficiency increase makes I don't know ... the boat is powered with a pair of 12V149TAs that scare the water into movement anyway.

Here's a picture of the completed installation showing the rudder installed.



*

 

[sunchaser]

In a similar setup (non prop) with a sheave or pinion gear,*it is called a pillow block bearing.

 

[Nomad Willy]

Rick,
What kind of bearing is in that strut and how does it fit onto the propeller nut?

Also:
What do you think of plastic prop to shaft sleeves? I've heard of them but never seen one. If they work at all they should be good on my Willy w only 37hp on a 1 1/4" shaft.

-- Edited by nomadwilly on Monday 27th of December 2010 11:18:43 PM

 

[RickB]

nomadwilly wrote:What kind of bearing is in that strut and how does it fit onto the propeller nut?



What do you think of plastic prop to shaft sleeves? I've heard of them but never seen one.*

The bearing is a standard cutless bearing. The "prop nut" is actually a stub shaft with the free end the same diameter as the main shaft and it fits in the bearing exactly the same as the shaft would if it were in a normal strut.

Re the sleeves, do you mean like the drive sleeves used on some outboard props? I have never seen or heard of using a plastic sleeve between the prop and shaft on a conventional drive so can't really comment, other than saying plastic is both a noun and an adjective and that can bring a lot of interesting issues into play on a drive train.

 

[JD]

nomadwilly wrote:
What do you think of plastic prop to shaft sleeves? I've heard of them but never seen one. If they work at all they should be good on my Willy w only 37hp on a 1 1/4" shaft.

-- Edited by nomadwilly on Monday 27th of December 2010 11:18:43 PM

I had a prop on a sailboat that used a plastic sleeve.* But it was used*by the PO*as a cheap way of fitting a used prop to a shaft that was to small for the prop.* I removed it and put a proper fitted prop on.* When we took it off the plastic sleeve looked all beat up and I'm not sure that the prop was ever really on the shaft correctly.*Looked a bit to*Mickey Mouse to me.*

*

 

[sunchaser]

"Plastic" sleeves/spacers are common on IO drives - I*have one that was used on*a 300 hp Bravo One.