Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 12-04-2018, 08:47   #16
Marine Service Provider

Join Date: Sep 2012
Location: Virgin Islands
Boat: 1999 Leopard 45, 45 foot cat, 1980 Hunter 33, 33 foot monohull
Posts: 575
Re: Folding Props a must have?

Quote:
Originally Posted by Training Wheels View Post
.......and less efficient in forward, more likely to snag lines, and more complex.
Lots of loose facts in this thread. Neither a feathering nor a folding prop has to be less efficient in forward. Yes, a feathering prop is more complex and is more likely ot snag lines, but it is more efficient in reverse. I have had both and prefer the folder.
__________________

contrail is offline   Reply With Quote
Old 12-04-2018, 08:49   #17
Marine Service Provider

Join Date: Sep 2012
Location: Virgin Islands
Boat: 1999 Leopard 45, 45 foot cat, 1980 Hunter 33, 33 foot monohull
Posts: 575
Re: Folding Props a must have?

Quote:
Originally Posted by rourkeh View Post
The idea of folding props on a production cruising boat to increase speed or fuel economy is a total waste of money. Now as equipment on a race boat I can see the need to squeeze out the extra knot or two any way possible..
Folding props very expensive, finicky, and have a tendency to lock up at exactly the wrong time. Most production cruising boats are relatively slow and so the extra knot or two will make little difference on a passage, and there is no science that I have seen that definitively proves any cost saving. Just another complicated piece of equipment to go wrong with no real benefit. But it sure is nice to tell everyone at the dock about your fancy xyzzy folding props and all the perceived benefits. I remember fondly trying to dock a friends FP 60' when one of his expensive folding props locked up in the wrong direction and all we could do is go around in circles and loose control of the boat. The owner had to send the props back to the manufacturer at great expense and they fixed the problem at further great expense shipped them back half way around the world and when we put them back on the boat they locked up again and we got to do more circles around the dock.
I think you have confused fixed and folding. A fixed prop can't get "locked up in the wrong direction". There is NO wrong direction. It is either folded or not. There IS a wrong direction on a feathering prop. I am not being pedantic....Discussions like this are muddled by using incorrect terminology..sorry.
__________________

contrail is offline   Reply With Quote
Old 12-04-2018, 08:55   #18
Registered User

Join Date: Jan 2014
Location: SICILY & CORSICA
Boat: lagoon450
Posts: 4
Images: 1
Send a message via Skype™ to cataloha
Re: Folding Props a must have?

Expensif but sécuriti ( cher mais sécurisant )
cheap for the engine .( permet d' économiser le moteur )
i have and i love, it' s really different and more good for all , excep money !!
cataloha is offline   Reply With Quote
Old 12-04-2018, 09:02   #19
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 20,216
Re: Folding Props a must have?

It depends. Might be hard to justify.
-Maybe where you sail is important. With good wind, your boat will reach hull speed with or without folding props. In light air you may gain some speed.
-But are you a light air sailor? or do you turn on the engine at 3 knots or less anyway?
-I 've had max props on 4 boats and like them. But worth the money? not sure really. If I'm going from point A to point B, I motor if I get down to 3.5 knots of speed. I want to get there before dark etc. The boat is just a tool to get from one place to another.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 12-04-2018, 09:06   #20
Registered User

Join Date: Oct 2014
Posts: 70
Re: Folding Props a must have?

Reference link to an article from 2009 comparing folding versus feathering.

This article is almost a decade old and does not include testing of several products which arrived too late for inclusion in the trials.

Folding and feathering propeller test
Montanan is offline   Reply With Quote
Old 12-04-2018, 09:55   #21
Registered User

Join Date: Jan 2017
Location: Everywhere
Boat: Fountaine Pajot Orana 44
Posts: 456
Re: Folding Props a must have?

Quote:
Originally Posted by rourkeh View Post
The idea of folding props on a production cruising boat to increase speed or fuel economy is a total waste of money. Now as equipment on a race boat I can see the need to squeeze out the extra knot or two any way possible..
Folding props very expensive, finicky, and have a tendency to lock up at exactly the wrong time. Most production cruising boats are relatively slow and so the extra knot or two will make little difference on a passage, and there is no science that I have seen that definitively proves any cost saving. Just another complicated piece of equipment to go wrong with no real benefit. But it sure is nice to tell everyone at the dock about your fancy xyzzy folding props and all the perceived benefits. I remember fondly trying to dock a friends FP 60' when one of his expensive folding props locked up in the wrong direction and all we could do is go around in circles and loose control of the boat. The owner had to send the props back to the manufacturer at great expense and they fixed the problem at further great expense shipped them back half way around the world and when we put them back on the boat they locked up again and we got to do more circles around the dock.
Any confused terminology aside ...

You specifically point out the additional speed gained. A cruising boat is slower, so the speed gains are MORE SIGNIFICANT than that of a racing boat. How about some simple maths ...

If you make 6 kts with fixed props and 7 kts with folded props, the difference in a 1000 NM passage is an ENTIRE DAY. You're traveling more than 16% faster.


1000/6 = 166.67 hours
1000/7 = 142.86 hours

7/6 = 1.167

Not to mention fuel savings, both those observable and unapparent. Observable being when you are motoring with one engine and the other prop folded. And unapparent being when you are sailing and getting to your destination sooner so you run the generator less, and spend less time underway with less opportunity to lose the wind and need to motor.

Plus everything everyone else is mentioning about added wear and noise by having the prop spin while sailing.

Sailing is about efficiency in all things. Whether you're cruising or racing or just dicking about.
LoudMusic is offline   Reply With Quote
Old 12-04-2018, 10:07   #22
Registered User

Join Date: Sep 2008
Location: Chesapeake Bay
Boat: Hunnter Legend 37.5
Posts: 250
Re: Folding Props a must have?

I have a folding prop on my monohull. Absolutely love it.
bensolomon is offline   Reply With Quote
Old 12-04-2018, 10:12   #23
Writing Full-Time Since 2014
 
thinwater's Avatar

Join Date: Nov 2008
Location: Deale, MD
Boat: PDQ Altair, 32/34
Posts: 4,973
Re: Folding Props a must have?

a. Does anyone have documentation of the speed difference under sail? I'm sure there are a range of answers and I would bet my wisdom teeth it's a lot less than 1 knot. I had lifting drives on my last boat, and lifting the leg completely out of the water was only 0.3-0.4 knots.

b. Difference in speed under power. Same question. I think it is obvious on the face of it that a fixed prop will be more efficient, all things being equal. I'm sure some of this can be corrected out by changing size, in which case all things are not equal, which is OK. The question is, how great is the difference?

From my point of view, a few tenths is a big deal, but then I've also seen the way most cruisers trim sails, so I must assume it is not to them. Same with dirty bottoms.
__________________
Gear Testing--Engineering--Sailing
Writing full-time since 2014
http://sail-delmarva.blogspot.com/
thinwater is offline   Reply With Quote
Old 12-04-2018, 10:26   #24
Registered User

Join Date: Nov 2010
Location: UK, Croatia
Boat: Fountaine Pajot Athena 11.6m Rapa Nui II
Posts: 443
Re: Folding Props a must have?

We fitted 2 Radiche folding props to our FP Athena last year after 7 years experience with fixed props.
The ambition which was realised, was to reduce drag under sail, particularly to improve lightwind performance and increase the low wind speed range for sailing and reduce the amount of motoring. We can now sail in significantly lower wind speeds. Another consequence is that reducing drag improved the tacking angle markedly, particularly in light winds. Side benefits are that we do not pick up lines (fishing, pots and lazylines ) so easily, the shafts remain stationary rather than rotating as with fixed props, so no whine and presumably reduced seal and shaft wear and finally, reduced drag when we motor under single engine.
In terms of motoring efficiency, we cannot measure a difference ahead, and in reverse we have no issues mooring stern to in a tight berth in our home marina.
We looked at feathering also but discounted that as it is complex and far more expensive. A number of boats we encountered with feathering prop problems re-inforced that decision.
All in all, we are pleased about going folding, and surprised how good the Radiche folders are, given that they are far and away the cheapest folders available. They are very simple and robust and just do the job.
Rapanui is offline   Reply With Quote
Old 12-04-2018, 11:12   #25
woc
Registered User

Join Date: Jan 2015
Location: Punta Gorda, Florida
Boat: Lagoon450
Posts: 64
Re: Folding Props a must have?

Quote:
Originally Posted by Krabimike View Post
I have been kicking around putting on folding props (flexfold). wondering what the thoughts are from those that are using them on the 450. $4,000US just wondering if it is dollars well spent?
The Flexfold 3 blade came with my 450. They are OK but are not as effective in reverse. Check out Gori folding props. People that are using them claim they have the same thrust in reverse as forward. Also, they have a “ overdrive “ setting that is useful when motorsailing with one engine, keeping the revs down whilst delivering max thrust. Not cheap but would be my choice if I had to do it over
woc is offline   Reply With Quote
Old 12-04-2018, 11:25   #26
Registered User
 
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,648
Re: Folding Props a must have?

Quote:
Originally Posted by rourkeh View Post
The idea of folding props on a production cruising boat to increase speed or fuel economy is a total waste of money. Now as equipment on a race boat I can see the need to squeeze out the extra knot or two any way possible..

Folding props very expensive, finicky, and have a tendency to lock up at exactly the wrong time. Most production cruising boats are relatively slow and so the extra knot or two will make little difference on a passage


For us an hour xtra knot is the difference between being able to complete a day sail into a cut or inlet and being forced to chose a night passage because we can’t make it to time the tide or the get in before the sun goes down.
zboss is offline   Reply With Quote
Old 12-04-2018, 11:34   #27
Registered User

Join Date: Jan 2017
Location: Everywhere
Boat: Fountaine Pajot Orana 44
Posts: 456
Re: Folding Props a must have?

Quote:
Originally Posted by thinwater View Post
a. Does anyone have documentation of the speed difference under sail? I'm sure there are a range of answers and I would bet my wisdom teeth it's a lot less than 1 knot. I had lifting drives on my last boat, and lifting the leg completely out of the water was only 0.3-0.4 knots.

b. Difference in speed under power. Same question. I think it is obvious on the face of it that a fixed prop will be more efficient, all things being equal. I'm sure some of this can be corrected out by changing size, in which case all things are not equal, which is OK. The question is, how great is the difference?

From my point of view, a few tenths is a big deal, but then I've also seen the way most cruisers trim sails, so I must assume it is not to them. Same with dirty bottoms.
Here is one article from a few years ago. 1kt gain was indeed at the high end of their results.
LoudMusic is offline   Reply With Quote
Old 12-04-2018, 11:55   #28
Registered User

Join Date: Oct 2012
Location: Home for a couple of years.
Boat: Beneteau 49
Posts: 402
Re: Folding Props a must have?

I really liked the FlexoFold props on my ex Lagoon 450.
I would do it again.
boom23 is offline   Reply With Quote
Old 12-04-2018, 13:00   #29
Registered User

Join Date: Feb 2005
Posts: 12
Re: Folding Props a must have?

For racing a folding prop is really a necessity if you're going to be competitive.
For cruising it's all about how fast you want to get there. If you just day sail like most of us really do, even if we're cruising it's usually a day sail from one port to another, does it matter if you get there one hour earlier at the end of the day ?

I've had fixed props, martec folding props and a max prop.
If you lock the fixed prop by putting it in reverse gear it does create a lot of drag and is about a half knot slower. If you let the shaft freewheel you will get some noise and some increased wear.

The martec is great in forward and you have to use a lot of throttle in reverse, but it does get you there.

The max prop is amazing in forward and reverse and has very little drag but does require greasing every season.

For the money, I'd go with the martec for the speed increase at minimal cost and just deal with the increased throttle required for reverse.
Tillerjockey is offline   Reply With Quote
Old 12-04-2018, 14:59   #30
Registered User

Join Date: Mar 2015
Location: channel islands
Boat: lancer 36
Posts: 281
Re: Folding Props a must have?

a half knot gain when I was racing was worth everything to me. I really liked taking home the hardware. performance still matters now in my cruising days but four large to replace my fixed prop? no way in hell. I can think of a thousand better uses for my money and most of them involve women.
__________________

jrbogie is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Folding / Feathering Props DInwood Propellers & Drive Systems 37 05-08-2008 07:15
Feathering or Folding Props - Increase Performance? ireaney Propellers & Drive Systems 43 08-04-2008 06:25
Props - Feathering or Folding? Exhale Multihull Sailboats 7 11-01-2008 07:50
Why I don't like folding props never monday Engines and Propulsion Systems 3 13-04-2006 07:32
Feathering/folding props mikereed100 Engines and Propulsion Systems 4 19-12-2005 19:14



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 02:05.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.