Folding vs feathering props

[Dockhead]

Originally Posted by robert sailor

Over the last 18 months we have been getting used to our Autoprop which is a type of folder and it seems to be very good in both forward and reverse.

The Autoprop (if you're talking about the Brunton Autoprop) is a feathering, not folding prop. But it differs from other feathering props in that it is also variable pitch.

They are the worst feathering prop made from the point of view of drag, but the self-pitching feature has some huge advantages.

They are pretty good in reverse, but beware the lag time while the blades flip over. Some people have crashed into docks because of that.

[Astrid]

Some of the newer Max props are adjustable for pitch without the need of being on the hard:

"As with all Max-Prop’s the Easy pitch is adjustable. With the Easy the pitch is adjustable in 2 degree increments, providing the ability to fine tune the loading of the engine. Moreover, pitch adjustment can be done in the water as the propeller does not need to be disassembled to change the pitch."
-- PYI Inc. Max-Prop PSS Shaft Seal Seaview Radar Mounts R&D --

[bgallinger]

I switched over to the Kiwi prop several years ago and I can say without reservation that it works great. I find no prop walk to speak of in reverse, less drag than a fixed prop and it functions equally well in reverse or forward. It's also about $1000 cheaper than any other folding or feathering prop.

[Ex-Calif]

One of the really smart guys above summarized it nicely.

It seems to boil down to

Feathering - Accept the inefficiency - can be important for those who motorsail/motor a lot. Enjoy the "positive" stopping and reversing. Live with the snags.

Folding - More efficient in forward. Some models have decent reverse stopping power. Less likely to snag.

Traditional Fixed prop - the one everyone should be using after they throw all their electronic nav gear overboard and buy a new sextant and sundial (sorry a dig at the integrated AP thread)

[Roy M]

I have a multihull with a Martec Mark III folding prop. Sure, the efficiency is lower in reverse, but I don't tend to use reverse all that often, for that matter, nor do I use the forward. For me it's a sailing advantage, especially if one traverses areas with kelp, or simply wants to have the smoothest water flow possible to maximize speed. I am happy with a full folder.

[mikereed100]

I think much of the decision between feathering and folding depends on the boat the prop will hang from.

Heavy displacement boat that is hard to stop? A feathering prop with it's greater thrust in reverse.

A daggerboard cat whose props dangle naked in the current? A folder to lessen the amount of crap you have to peel off the prop, (although if you don't have to remove it from the prop you will probably have to remove it from the rudder).

A straight shaft with a large angle between hull and shaft? A feathering prop will probably offer less resistance when sailing, though this may be negligible.

[Cheechako]

Feathering props are very good for reverse thrust etc. Maybe some of the newer folders are better than they used to be, but really, the old type are only good for getting out of the marina for racing. JMHO!

[Jim Cate]

Originally Posted by Cheechako

Feathering props are very good for reverse thrust etc. Maybe some of the newer folders are better than they used to be, but really, the old type are only good for getting out of the marina for racing. JMHO!

But why would anyone buy an "old type" folding prop when the Flex-O-Fold is one of the least expensive (non-fixed) props on the market?

And having now done over 40,000 miles of cruising with our F-O-F I reckon that they are definitely not "only good for getting out of the marina for racing"!

You are entitled to your humble opinion, but I see little to support it.

Jim

[Cheechako]

Originally Posted by Jim Cate

But why would anyone buy an "old type" folding prop when the Flex-O-Fold is one of the least expensive (non-fixed) props on the market?

And having now done over 40,000 miles of cruising with our F-O-F I reckon that they are definitely not "only good for getting out of the marina for racing"!

You are entitled to your humble opinion, but I see little to support it.

Jim

as I said: "Maybe some of the newer folders are better than they used to be,..."
I'd be interested in seeing a full speed to dead stop test comparing a Max to the Flex o Fold though!

[Jim Cate]

Originally Posted by Cheechako

as I said: "Maybe some of the newer folders are better than they used to be,..."
I'd be interested in seeing a full speed to dead stop test comparing a Max to the Flex o Fold though!

I'm sure that the Max, or other good feathering prop would win that contest.

But crash stops are not the main determinant for prop selection for me...

Jim

[sailorboy1]

3 years ago when I was looking to get a feathering prop and started reading the various tests I discovered that the reverse thing wasn't really very supported and that the FOF was about the same in reverse and a lot better in forward, and cost $1000 less.

[silverp40]

To second Jim Cate, I like our Autostream feathering prop, one additional reason because it is stainless steel.

It is harder than a bronze prop and in my experience over 12 years or so less prone to corrosion (on a stainless shaft).

I think they use very good austentic type stainless (duplex) for this prop's blades and body.

[mikereed100]

Originally Posted by sailorboy1

3 years ago when I was looking to get a feathering prop and started reading the various tests I discovered that the reverse thing wasn't really very supported and that the FOF was about the same in reverse and a lot better in forward, and cost $1000 less.

$1000 less than what? When I was doing research at about the same time, the Kiwiprop was $300 less than FoF. With a cat, that meant the Kiwi's were $600 less than FoF and was the main reason I went with them.

Here's a link to an excellent comparison between props, confirming that FoF does indeed work well in reverse (and is more expensive).

Voile Magazine 2009

[fstbttms]

Originally Posted by Astrid

Some of the newer Max props are adjustable for pitch without the need of being on the hard...

At the risk of repeating myself for the umpteenth time- every single Max Prop model ever made can be installed, removed, repitched, lubricated, whatever, while the boat is in the water. It is done by PYI-recommended divers every day and if their experience is anything like mine; with a 100% success rate and zero lost parts.

[Ex-Calif]

Originally Posted by fstbttms

At the risk of repeating myself for the umpteenth time- every single Max Prop model ever made can be installed, removed, repitched, lubricated, whatever, while the boat is in the water. It is done by PYI-recommended divers every day and if their experience is anything like mine; with a 100% success rate and zero lost parts.

I think he is referring to the maxprop easy which is externally adjustable rather than the classic which needs to be disaseembled and re indexed.