450: Folding Props a must have?

[Snowpetrel]

Aside from the other advantages of a folder or feathering prop, there is also a big benefit to steering control when one is fitted ahead of a rudder as all the turbulent water coming off a fixed prop doesn't do the flow over the rudder any good when sailing. Given the short rudders on many cats this could be pretty important.

[Otia]

It's a nice to have, not a must.
With Volvo engines and a saildrive you get an annoying transmission noise as you sail, just for that I want a folding prop.

[malbert73]

Flexofold is awesome. Makes a big difference sailing in marginal light breeze and moderate conditions. Superb in FWD, adequate in reverse. No snagging lines under sail. 2K each about

[thinwater]

Originally Posted by LoudMusic

Here is one article from a few years ago. 1kt gain was indeed at the high end of their results.

Thanks for the link. It answers all of the questions other than user anecdotes.

[stnick]

If it moves under a boat the day will come where you will have to get in the water to fix it !
If thats ok with you than a folding prop is for you !

[c-reel]

Sorry to intrude, but when you guys are finished debating on the fix vs not-fix prop, and more specific on L450 and Yanmar SD60, can anyone confirm an installation of Ambassador RoPe-cutter, with Flexofold (lagoon option) on a Lagoon 450 ? ...

[Adelie]

Originally Posted by c-reel

Sorry to intrude, but when you guys are finished debating on the fix vs not-fix prop, and more specific on L450 and Yanmar SD60, can anyone confirm an installation of Ambassador Robe-cutter, with Flexofold (lagoon option) on a Lagoon 450 ? ...

Are you worried about you bathrobes going overboard and getting caught in the prop or are you going to be visiting places where a lot of people wear robes?

[c-reel]

Originally Posted by Adelie

Are you worried about you bathrobes going overboard and getting caught in the prop or are you going to be visiting places where a lot of people wear robes?

Corrected. Thanks. While i guess robes could be problematic in both the cases you have described as well

Regarding ropes, i'm more worried about the later!!

[Adelie]

Where in SoCal are you, LA or SD?

[contrail]

Originally Posted by thinwater

Thanks for the link. It answers all of the questions other than user anecdotes.

Be a bit skeptical about the linked article. You will see that Flex o fold comes in as best under power, in forward. The article also states that you get the same speed at about 200 RPM less. But, as you well know from your own testing, the devil is in the details. In this case, the tests are done with the prop specs recommended by the respective manufacturer, rather than a pitch and diameter that is consistent between brands. I have flex o folds, myself (having sailed thousands of miles with fixed and Max Prop feathering props) and I love them for all the reasons given, plus more. And I do get the same speed at 200 RPM less. BUT, flex o fold has a record of often specifying an overpropped size, as they did with me, and that will get you those results. And they are not great at rectifying their error. So if you understand the consequences of overpropping, and are prepared to take the steps necessary to avoid them, you are fine, and you may have a better loaded engine, as well. If you don't.......

On another note, there is absolutely no reason that a folding prop should be less efficient, in forward, than a fixed prop. A feathering prop MAY be, because the nature of the beast is to have minimal twist in the blades. By the same token, a feathering prop will almost always be the most efficient in reverse, while a folding prop has to be the least. Some are better than others, and the flex o fold is good enough to make the reverse thrust pretty much a non issue. Love mine, but beware!

[Emerald Sea]

Its interesting when people say its worth the money? Just what is that based on when spending $4000? Lets look at few things here
- There is no internal rate of return, simply as you are not saving any money i.e. fuel. Folding/feathered props do not provide any boost in performance - like for like. So the idea of saving money here is not substantiated.
- Speed advantage - sailboats are slow! Average 6kts on a passage - say with folding/feathered props. If that now becomes 5.8kts with fixed props (Practical Boat Owen magazine), on a passage of 200nm that's slightly more than 1hr time saved when the net time was 33hrs! Is this really efficiency?
- Maintenance? Sail drives are designed to free spin or Yanmar or others would be specifying folding/feathered props. I have never heard of anyone having additional maintenance because their props spin freely.

Dollars well spent? I don/t see it. They are a Nice To Have, but not essential.

I still have them on my 450 and it was an option I ticked off - in 2014 they were $2600!

[c-reel]

Makes a lot of sense - of course, rule #1 of social media & L450 is Paul and Stephen always have to be listen to ...

The factory option cost hasn't changed (so with inflation at e/$ constant, may claim it went down). It is one of these options which looks cheaper to install rather than replace later, as it will be more expensive.

Maybe the speed would be more than that, certainly an important value for an outremer 5x (while in this case, even the factory option is >3000$ per prop!)

Sorry to keep bringing the same topic, but another value of the folding props is the fact they offer less drag to catch whatever you may encounter (nets, ropes, robes ;-).
Nice to have but with even more value in some areas. Fishing lines getting into the SD is a personal nightmare.

And this is why to further increase the protection, adding rope-cutter would be perfect.
But someone who is always to be listen to on the social media made a comment that you cannot instal ambassador rope-cutter on SD60 with L450.
Ambassador claims they have sold many rope-cutters for L450 (without details on the type of props).
Have been looking for a real case. No-one confirmed yet...
And strangely, the SD60 option for the Ambassador Rope-cutter isnt on their website.

There are for sure some rope-cutter installed on SD50 on L440 (saw a picture). But this picture was not on folding prop.
Would a Lagoon factory option flexoprop be preventing the installation of the rope-cutter ?
This could be a reason not to click on the nice-to-have 2500$ option.

Originally Posted by Emerald Sea

Its interesting when people say its worth the money? Just what is that based on when spending $4000? Lets look at few things here
- There is no internal rate of return, simply as you are not saving any money i.e. fuel. Folding/feathered props do not provide any boost in performance - like for like. So the idea of saving money here is not substantiated.
- Speed advantage - sailboats are slow! Average 6kts on a passage - say with folding/feathered props. If that now becomes 5.8kts with fixed props (Practical Boat Owen magazine), on a passage of 200nm that's slightly more than 1hr time saved when the net time was 33hrs! Is this really efficiency?
- Maintenance? Sail drives are designed to free spin or Yanmar or others would be specifying folding/feathered props. I have never heard of anyone having additional maintenance because their props spin freely.

Dollars well spent? I don/t see it. They are a Nice To Have, but not essential.

I still have them on my 450 and it was an option I ticked off - in 2014 they were $2600!

[rabbi]

Originally Posted by Emerald Sea

- Maintenance? Sail drives are designed to free spin or Yanmar or others would be specifying folding/feathered props. I have never heard of anyone having additional maintenance because their props spin freely.

Saildrives has some wear even if free spinning. While bearings and pinions are not really affected much there is still the lower saildrive oil seal on the prop shaft.
The oil seals have a finite lifetime (in terms of revolutions, even when free spinning), and the oil seals over time create a groove in the prop shaft (which costs ~800 Euro to replace).

So yes there is additional maintenance / cost involved whe a saildrive is free spinning, but not much.