Help finding a Propeller

[fstbttms]

Originally Posted by MicHughV

As it is shown now as per the pic above, the hub of that prop looks like it is immediately adjacent to the aft end of that strut, with almost zero clearance, meaning when the engine is put into forward gear, that prop is likely rubbing up against the strut.

The hub is cracked meaning that the bore diameter is larger than it used to be. The prop likely slid up the shaft after the damaged occurred.

Originally Posted by MicHughV

If the prop had hit something, you'd likely see a bent blade, but I see none, which leads me to believe the crack in that hub location is likely the result of contact between the forward prop hub and the aft end of that strut.

The prop is made of plastic, therefore no bent blades.

[skipperpete]

Originally Posted by fstbttms

The hub is cracked meaning that the bore diameter is larger than it used to be. The prop likely slid up the shaft after the damaged occurred.



The prop is made of plastic, therefore no bent blades.

Well spotted fstbttms!

[MicHughV]

a plastic prop ??.....ah well....didn't see that one coming.....maybe it's possible to get a replica made from bronze...???

[Uncle Bob]

My go to would be get a suitable new prop, disconnect the coupling at the gearbox and slide the shaft back sufficiently and have a spacer made to extend the shaft, coupling to gearbox. If insufficient space then a longer shaft, positioning the new prop at the required position.

[DougR]

Couple of thoughts, comments...
- first photo shows that the prop “overhang” beyond the strut is about one shaft diameter, just about where it should be
- ideas of adding “ drivesavers” or other spacers or getting a longer shaft to move the prop aft for more tip clearance are typically ill advised. Normal prop recommended overhang beyond the strut is one shaft diameter, or occasionally 1.5 diameter.
- As noted, the existing prop design was usually installed to move the blades aft to obtain adequate blade area and tip clearance when repowering from a 1:1 ratio atomic four to a Diesel engine with a deeper reduction ratio......but we know nothing about the engine, it’s power/rpm and it’s reduction ratio.

- perhaps a workable solution is the fitting of a three blade feathering prop, which will provide enough blade area to absorb the available power, or a three blade folder which will do the same and have the advantage of moving the blade pivot point aft and allow slightly larger diameter.

But for either of these we need to know about the particulars of the power package in the boat.

[Searles]

Yep would go with a drive saver ,many different brands ,will give you at least more space ,weld up the old prop and re fit .⛵️⚓️

[Jim Cate]

weld up the old prop and re fit

Hard to do if the prop is plastic as reported upthread!

Jim

[c.K.]

Originally Posted by boots99

My boat partner recently hit something while he was out sailing and broke our prop. I'm having a hard time finding a replacement because of the length of the hub. The prop shaft extends only a couple inches past the strut, and the nuts that hold the prop on are at that point, deep inside the hub, about 10 inches in from where the prop blades are, so this long hub provides the extension that gives the prop clearance from the bottom of the hull. Anyone have any ideas where something like this could be found. I have searched pretty extensively on the internet and have not found anything, and the mechanics at our marina said they can get something custom made (but that's expensive). This is a 12 inch, 8 pitch prop.
Thanks

How about having the crack welded

[fstbttms]

Originally Posted by c.K.

How about having the crack welded

I guess it has to be said a whole bunch of times- It's a plastic prop.

[Uncle Bob]

Originally Posted by fstbttms

I guess it has to be said a whole bunch of times- It's a plastic prop.

Doesn't matter how many times it is said, if people don't read the other responses but just answer the question asked then this is what you get.
Aint literacy a wonderful thing.

[Madehn]

Actually some types of plastic can be welded by the right type of equipment. I would be tempted to take it is and try that at a fabricator. I would also have a metal collar made to go around the hub to give it added strength. 1/4 inch of stainless steel cut from a pipe of the right diameter and then that fitted in with plastic “filler” around the hub should be plenty strong enough and I think it could be streamlined enough to make it work. JMHO

[fstbttms]

Originally Posted by Madehn

Actually some types of plastic can be welded by the right type of equipment. I would be tempted to take it is and try that at a fabricator.

Or, he could do it the right way and replace the broken prop with a new one. You know, and not throw money at a half-assed "repair."

[sanibel sailor]

They made over 400 O'Day 28's. How have others solved this issue? Strut must be factory position. I would think smaller diameter and more blades. It is just an ugly arrangement as is.
Have you tried an O'Day forum?

[capn ken]

Originally Posted by fstbttms

It is not a "custom job." It is not a trailing log prop. It is an "Extendo Prop" and was designed to be used on boats repowered with diesel from the Atomic Four gas engine. No longer in production however.

This site always amazes me !the help and courtesy are amazing !

[ItDepends]

Originally Posted by fstbttms

It is not a "custom job." It is not a trailing log prop. It is an "Extendo Prop" and was designed to be used on boats repowered with diesel from the Atomic Four gas engine. No longer in production however.

Matt,

Isn't it frustrating when you post the right answer, and nobody seems to read it, but they continue to run off with craziness?

Back to the OP, you have a problem here. The maximum distance from the forward face of the prop to the aft face of the cutlass bearing is 1.5 times the shaft diameter. So despite the postings here NO you can't just make the shaft longer! You're best bet is to consult with a propeller expert, and have him review the clearances and dimensions. There will be no perfect solution, but I can assure you so far none of the advice posted here so far is close to the best you can do.