Folding Versus Feathering Props

[Windseeker]

Originally Posted by Sabbatical II

it does have significant prop walk

I read this and I'm ready to start drinking again. Not that it is Sabbatical's fault. I've only learned what you guys have taught me, and that is the feathering prop will present it's leading edge in reverse which is supposed to eliminate prop walk as compared to other props. Perhaps there is an adjustment that can be made? That is one of the beauties of the Autostream??? Can something other than the prop cause prop walk?

[carstenb]

Well Windseeker - have another drink.

All boats have prop walk, even when sailing forward. You don't notice it when going forward because you automatically neutralize it by using the rudder. Since the prop wash runs back along the rudder, very little turning is needed to negate it.

When you are in reverse, there is no prop wash along the rudder, which means you will need to get up enough speed for the rudder to "bite" in the water (water speed across the rudder generated by the speed of the boat through the water).

Some props have excessive "swalk", some have little. Generally, feathering props have less, but to my knowledge no props have none.

Make sense?

[denverd0n]

Carstenb is right. If you really want no prop-walk at all, there is only one way to achieve it: twin engines with counter-rotating props. Each prop will have its own prop-walk, but the two will cancel each other out.

[bgallinger]

I have had a Kiwi feathering prop for a few years now and love it. Forward or reverse makes no noticeable difference.

[Windseeker]

Yes, the prop wash against the rudder makes a lot of sense. Certainly explains the better control in FWD. Thanks!

I hope I can tell this joke without getting thrown off this site:

What are three words you hear me screaming at the helm when backing my boat that you will never hear in a whore house?

"Bite, you Cocksucker!"

[carstenb]

Originally Posted by Windseeker

Yes, the prop wash against the rudder makes a lot of sense. Certainly explains the better control in FWD. Thanks!

I hope I can tell this joke without getting thrown off this site:

What are three words you hear me screaming at the helm when backing my boat that you will never hear in a whore house?

"Bite, you Cocksucker!"

ain't no joke. hear it lots in tight marinas

[Octopussy]

We were told by boatyard folks the same thing regarding folding props... reverse is non-existent!

We have Autostream feathering props... they rock. I have to say, for having a sailboat, we received lots of "props" for our props when our boat was out of the water. We service them here in the US through Martec Sailboat Propellers.

Also, someone on page 1 of this thread complained about feathering props and getting lobster pot lines caught all of the time. We use Spurs Marine - Ship Cutters on our feathering props. Got lots of "props" for those too.

Good luck,
Octopussy

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[sailorboy1]

Originally Posted by Octopussy

We were told by boatyard folks the same thing regarding folding props... reverse is non-existent!

Just a myth started by the feathering prop people. I have a 3 blade FlexoFold and my last boat had a 3 blade Maxprop. They both have the same performance in reverse.

I think difference in prop walk between a folding and a feathering prop doesn't really matter much. Maybe if you plan to be mostly backing up all the time it is something to consider. Otherwise a folding/feathering prop is about low drag when sailing and good peformance when motoring forward.

[Windseeker]

Reverse is what I am most after. I have to back my boat into my slip. I'm fairly well protected except from a NNW cold front which can blow me around pretty good. I'm sometimes docking at an angle at "ramming speed" - as the wife calls it. It can be a nail biter at times. It takes too long to get this boat turning before I start running out of water. On some days it takes 3 or 4 tries. I'd rather try this than a bow thruster $$,$$$.

So far I like the Autostream and it specs out well for prop walk and reverse. I downloaded the installation instructions for this unit. The instal is within my capabilities and I have a freshly calibrated 1/2" torque wrench. the only gotcha I read is on the shaft nut fitting and clearances. If for some reason it does not fit, I have to pull the shaft and have it machined. That means dropping the rudder. That would be a nightmare bigger than I want. What is the likelihood of that?

Q: I'm just wondering if pulling the old prop and taking all the necessary measurements is worthwhile? I can't imagine it would be difficult. I asked Autostream this same question, but they must be at a Tradeshow. . .

PS: Any Featherstream or Luke fans