Most reliable feathering propeller

[Cheechako]

I've had 5 Max Props on different boats. All were good with no issues. Feathering is the way to go not folding IMHO.

[01kiwijohn]

Can't add much here I'm afraid.
Had a Kiwi Prop since 2008(?) and had to replace a couple of blades, which, incidentally saved a bunch of other money. Just had a diver replace a damaged one this past week. (To match the pitch, I use a vernier depth gauge to measure the pitch screw with the one taken off) We typically motor about 200 hours per year.
You do lose a little efficiency, as with any straight blade design. Backing down was a quickly learned experience, but no big deal. I use "Barnacle Blocker" paint and it works as well as anything. I'd buy another one.

[boatman1]

About 1000 hours of motoring in eight years with a Kiwi prop and it’s been good to me. I grease it once a year when hauled and it does fine. This is with a 56 hp Yanmar on a Tartan 37 monohull. I may be wrong, but I don’t think “P” factor is going to be affected by the type of propellor, only by the different pitch of the ascending and descending blade(s) due to the the prop shaft not being aligned with the flow of the fluid (water) in which it is functioning. I wouldn’t have thought prop creep (“P” factor) would be an issue with sail drives, where the axis of the drive shaft(s) is parallel to the “apparent” flow.

[a64pilot]

Originally Posted by fxarcher

I would love for someone to explain the advantages/disadvantages of a Hundested propeller system versus Autoprop.

I know Hundested (Denmark) starts somewhere around 150HP and does not require a reduction/reversible gear when coupled to low RPM engines.

Thanks

A controllable pitch propellor in my opinion is superior as long as you have the knowledge of what your doing and have the tools available to make the decisions, those tools would be a pyrometer and fuel flow meter, ideally a torque meter, but I don’t think that’s likely.

An Autoprop is for those that only want to know that to go faster all you do is push the lever further, it’s supposed to be purely automatic, but as with most things that way, it’s pretty good, but not as good as an experienced person with the proper instruments can be.

Autoprop marketing of course wants you to believe that it is always at the best, perfect pitch, but I suspicion that isn’t exactly the whole truth, but think it’s better than a fixed pitch prop.

If a controllable pitch prop were available for me, I’d have gone that route, and installed the instrumentation.

[freshalaska]

Originally Posted by fstbttms

Having installed and maintained many, MANY Max Props over the last couple of decades, my opinion is that the Classic is as reliable and robust a piece of equipment as you can install on your boat.

As reliable as a fixed blade prop?

[a64pilot]

Originally Posted by boatman1

About 1000 hours of motoring in eight years with a Kiwi prop and it’s been good to me. I grease it once a year when hauled and it does fine. This is with a 56 hp Yanmar on a Tartan 37 monohull. I may be wrong, but I don’t think “P” factor is going to be affected by the type of propellor, only by the different pitch of the ascending and descending blade(s) due to the the prop shaft not being aligned with the flow of the fluid (water) in which it is functioning. I wouldn’t have thought prop creep (“P” factor) would be an issue with sail drives, where the axis of the drive shaft(s) is parallel to the “apparent” flow.

Prop walk isn’t P factor. If it were then boat speed wouldn’t affect it, and as you say it would be directly proportional to shaft angle, and it’s not.

I suspicion that it’s related to pitch, a higher pitched prop seems to walk more, I think it’s literally that a high pitched blade acts like a paddle wheel and walks the prop sideways at low or zero forward speed.
But that’s just my theory.

[CarinaPDX]

For simplicity and robust design it is hard to beat the Luke feathering prop. It has been around for about a century. The pitch is set by machining the stops, so more of a pain to get it right but nothing to go wrong either. The big advantage is that, unlike almost all other feathering props, the blades are cupped (instead of flat) and thus have efficiency approaching fixed blade props. It has slightly higher drag under sail than other feathering props so not attractive to racers, but for cruisers it is a great choice.


Greg

[boatman1]

A64 pilot: I believe that the reason boat speed affects the amount of creep is because of lack of effectiveness of the rudder at low/no speed through the water. Angle of the propshaft does affect the amount of asymmetric thrust, in a boat and a propellor driven airplane. During takeoff in a taildragger, when the the empennage has sufficient authority to raise the tail wheel off the ground, then the angle of the axis of the prop changes relative to airflow and rudder correction becomes necessary. As the angle of attack Increases, more rudder is required to counter the asymmetric thrust. Same thing is happening with a boats’ prop: it’s just that the rudder is almost ineffective in reverse at low/no speed through the water. You’d have creep when placing the gear in forward from a stationary state but for the effectiveness of the water flow around the rudder.

[boatman1]

You may be right that there is a “paddlewheel effect” from the ascending blade, producing a side ways thrust in addition to the asymmetric forward/reverse thrust due to “P”factor.

[a64pilot]

Trust me, I’m a long time tailwheel pilot and have flown hundreds of airplanes that were, up to 1700 SHP ones.
I understand P factor, I just don’t think that is what prop walk is.

Shaft angle measured by my Craftsman electronic level is 4 degrees, which is almost nothing, it’s so small it looks level to the eye.
However with my fixed three blade 18x14 prop, prop walk is epic, I can easily turn the boat 360 to Starboard in just barely over a Boat length, but forget a standing turn to Starboard, it ain’t happening.

[Diesel Bill]

It's nice to know there are choices. My current boat came to me with Luk feathering reversible props. This is my 1st twin engine boat . When the boat was pulled in La Paz 3 years ago. I put a zerk in the hubs and forced in a full tube of marine trailer wheel bearing grease each side. Am equal amount of old grease came out. The wheels are 24 " I can tell they work by the clunk they make when reversing. From neutral to either direction fwd or rev they clunk as the blades go into position. I don't hear much about this brand. Any body got any info on them? They pull like a tug boat with the twin Perkins 4-236 lowboys.

[Diesel Bill]

By the way I agree with a64pilot about prop walk. We used it to turn a loaded 65,000 DWT oil tanker 90 deg. around to stb. with out making any way on, neither ahead nor astern in the Bay Area. Had to back into a dock to unload from stb. side. Tight quarters indeed for a loaded tanker. The old man knew his stuff. By the way the wheel on the tanker was fixed pitch, 17 foot diameter. I don't remember the pitch number but it was big.

[S/V Alchemy]

I have a four-bladed feathering VariProp for our steel cutter. Five years in, it's still doing well. The reason I chose it is because the forward and astern prop pitches can be set a) separately and b) in the water if you are careful. I like a flatter pitch in forward to reach my correct RPM but a coarser pitch in reverse for close-quarters action.

[Lodbrog1]

I had a classic MP 3 blade Classic for a couple of years. It died from improper maintenance at the last yard and the hub was cracked and not fixable. So I ponied up for a 4blade easy and have yet to use it (next week). I am curious of the change in umph going to weather and general use. So if anyone has some experience with the 4 I'd love to hear from you.

[Aqualibrium]

I’ve had Autostream feathering props on since launching in 2014.
5 yrs and 17.000 nm later I can only say that I love them, great reverse power, no maintenance problems,
Just gone back into water at Boatworks where I had them apart, no wear evident.
Needed anodes and a few other consumables, rang the factory in Victoria and the parts arrived in an express post bag the next afternoon.
Cannot recommend them highly enough.
Sailing speed jumps 0.5 k when both are feathered

Love em