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Folding - Feathering Props


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#1 jerryj2me

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Posted 01 July 2010 - 08:19 PM

So I got a boat with a stock prop on there. 3 blade, non feather, non fold.

Am thinking of getting a fold/feather instead to help with speed a touch.

Boat is 1992, 38 foot, Beneteau First 38S5, PHRF around 105-108

Not sail drive - its a Volvo Penta with a conventional shaft drive.

Some opinions please -

Whats it going to cost, and what would you suggest?

I had a folder on my Ericcson, and it had the usual aggravations
while backing.

#2 Mistaken

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Posted 01 July 2010 - 08:49 PM

Let the discussions begin - to be honest, this has been hashed out numerous times on SA and in other forums, so here we go again!

In order to really answer your question you really need to give us more details & your priorities - are you going to be racing only, racing & cruising, or simply cruising?

#3 Moonduster

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Posted 01 July 2010 - 11:18 PM

If you're interested in maximum performance while buoy racing, I'd go for a Martec two-bladed folding prop.

If you're interested in dramatically improving performance without losing your ability to deliver full horsepower into the water when motoring (ahead and astern), then I'd go with a Max Prop 3-bladed feathering.

Of course there are plenty of other brands that have fine reputations - but Martec and Max Prop seem to be the market leaders and usually with good reason.

If price is really a concern, they you should probably hold off. The prices are really egregious. But then, fast is fun!

Good luck

#4 jerryj2me

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Posted 01 July 2010 - 11:40 PM

Let the discussions begin - to be honest, this has been hashed out numerous times on SA and in other forums, so here we go again!

In order to really answer your question you really need to give us more details & your priorities - are you going to be racing only, racing & cruising, or simply cruising?


Race and cruise - and I expect that its out there already but I could not find it.

Got a link?

Also - below is what they are telling me from Max-Prop - feel free to comment -


Thank you for your interest in the Max-Prop feathering propeller for your
Beneteau 38S5. From the information that you provided following is my
recommendation.

2 Blade 17” diameter by 11” pitch for a 30mm shaft $1900.00
3 Blade 17” diameter by 10” pitch for a 30mm shaft $3150.00
3 Blade V.P. 17" diameter by 10" pitch for a 30mm shaft $3975.00

With regards to powering performance, both two and three blade propellers
will power the boat well in flat water. The three blade has a major
advantage when going against heavy winds and seas the three blade will keep
boat speed by up to 30% better than the two blade. Moreover, a three blade
propeller will run much smoother and reduce vibrations as it is balanced
around three points as opposed to two.

Under sail either propeller will increase the sailing speed by about 15% on
average. The largest difference being noticed when sailing in light air.
When with the fixed propeller the vessel struggles to get through a tack and
you have to bare off to gain speed exiting the tack. With the Max-Prop you
will be able to carry your speed through the tack much better as you are not
dragging a bucket. This means you exit with much more speed and a higher
line. Basically it makes it fun to sail in light air when the boat
struggles with a fixed propeller.

Please feel free to contact me if you have any further questions or if you
would like to place an order.



#5 longy

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Posted 02 July 2010 - 12:19 AM

If you are certain that your current prop dimensions are perfect for your boat/loading, then look at the Gori 3 blade folder. It gives you all the three blade benefits plus the benefit of a folder with the blades getting out of the flow. The blades are also much thicjer & stronger than Max blades, thus much harder to prang. And these props have an "overdrive" mode: you force the blades to swing open into the 'reverse' position when motoring forwards, this gives the blades more pitch, allowing you to extend fuel range at moderate speeds.
The only downside I've heard of is they can wear thru the urethane bump stops, & Gori is very proud of them.

If you are not certain of your prop numbers, and want to change NOW, go with the standard three blade Max. They have a big enuff data base to advise you on prop settings, I've never found them more than 1 setting off of what I ended up with. And mostly that's because those boats wanted to pitch as high as possible for long range cruising. Usually, one haul & hang in the slings while you change settings runs $200 or so, so that getting the externally adjustable unit is not worth the extra money.

If you're not certain of your prop numbers & can wait, find a prop shop that will work with you & try different used props on your boat. A good diver can change them underwater easily.

#6 New Morning

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Posted 02 July 2010 - 02:48 AM

I had a the three blade Volvo folder on a saildrive and it worked great, even in reverse.

On my new boat I've got a Gori and it definitely folds flatter with less drag. The only issue I've had after 5,000 miles is be sure to keep the teeth on the folding gears fairly clean. When these accumlate hard growth (which can happen very fast in the right conditions), the opening/closing action as you shift from forward to reverse and back can be slow and the engine unresponsive. This would be a problem with any folder, even the aforementioned Volvo, if it's gearing is expose.

I think the feathering props don't have this issue, but then they don't fold flat.

#7 RockHead

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Posted 02 July 2010 - 04:52 AM

First of all, note my sig and know what I do for work to pay for my sailing habit... And yeah, I bought an ad months ago, but I'll try to keep it mostly, somewhat, a little neutral. :lol:

There are a couple of good prop tests out there, and some real stinkers. The most controlled, scientific one was done some years ago by the University of Berlin for the German magazine Die Yacht, primarily on 3-blade low-drag props. Lowest drag under sail: Flexofold and Gori. 2.7 pounds of drag under sail at 6-7 knots vs. 95 pounds for a freewheeling fixed 3-blade and 149 pounds for a 3-blade in gear. I don't recall exactly what MaxProp was -it was higher, but still dramatically lower than a fixed prop. I'm really a bit dubious of the broad % speed claims by MaxProp. The drag of the prop is a high % of total drag a low speeds, but its % of total drag decreases with boatspeed as wave form drag increases as you approach hull speed. So you'll see bigger relative improvements in light air vs. fully powered up. Seriously though, if you have a sailboat with a fixed prop, get rid of it!

Drag under sail is primarily a result of total exposed frontal surface area. Folding props have an advantage here -due to the very simple mechanisms, their hubs are much smaller than the featherers which have more complex mechanics, thus folding is lower in drag. This test also compared the efficiency of converting your engine's HP into actual thrust. The two most efficient were Flexofold 2-blade, Flexofold 3-blade and then fixed. Another good recent test came out last May (?) in Yachting Monthly. You can find a copy of that here. Read it and draw your own conclusions.

The other big problem with feathering props is their flat blades, which are grossly inefficient. They were all pretty uniform in efficiency, at about 1/2 the efficiency of the Flexofolds. They can also cause vibration and resonance problems due to excessive tip loading as a result of this. Look at a fixed prop -it has constant pitch, where the angle of attack changes from the root of the blade to the tip, due to the increasing speed of the blade moving out from the shaft. This is what's missing from all but 1 or 2 feathering props (which are insanely expensive). I recently re-propped a 60' tourist schooner from MaxProps and solved a vibration problem which was due to excessive tip loading due to the flat blades. Flexofolds have constant pitch, as well as proper cross sectional airfoil shape which develops lift/suction on the forward side as well as basic thrust from the aft side. This is one of the reasons our props have such great efficiency & thrust.

The third factor in efficiency and thrust is tip shape. Much like your sailplan, a more elliptical shape is more efficient, reducing tip vortices compared to square tips (like Gori 2-blade).

Speaking of Gori, their 3-blade is a stunningly gorgeous piece of kit. If you do a LOT of long distance motor sailing, the overdrive may be worthwhile, some people love it. Randy Repass (founder of West Marine) and the owner of Hanse Yacht both found it more trouble than it's worth. Guess what they have now... and what's now standard on every Hanse (and every Beneteau First, US built J/Boats (except 105), Morris, Hylas and lots of new Gunboats, Swans, X-Yachts, and I could go on).

People like to make a big deal out of the reverse performance of feathering props, but the Yachting Monthly test shows that the best performing folding prop can stop your boat from speed in only 9/10 of a second more than the best feathering prop tested.

The question of 2-blade vs. 3-blade has a couple of factors. 3-blade will have a bit more drag due to a larger hub. A 2-blade is more efficient because each blade rotates 1/2 a revolution before it encounters turbulence from the other blade. A 3-blade only rotates 1/3 of a revolution before it encounters the turbulence. So a 2-blade will run at slightly lower RPM for a given boat speed in flat water and calm. OTOH, a 3-blades additional blade surface area gives it more "bite" on the water, so it will accelerate and decelerate a boat more quickly in docking, and maintain a higher average speed punching through waves. Then throw cost into the equation and judge what is best for your use.

P.S. Thanks for sharing the Maxprop pricing, I seriously kick their ass on price. Save 1/2 to 1 full boat unit with a Flexofold. Click on the logo or PM me B)

#8 Joakim

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Posted 02 July 2010 - 07:26 AM

Here are some more tests:
http://www.propelspe...e_test_2008.pdf
http://www.propelspe...rison_chart.pdf
http://www.bomarine....april-2009.html

I would not buy a feathering propeller, especially for a shaft drive, which is probably inclined to the flow. Feathering blades are usually locked to each other, thus they can not turn completely parallel to the flow, if the shaft is not parallel to the flow. I don't see any real benefits, which would compensate the much higher price and complexity and a little more drag compared to a good folding propeller.

I don't think performance on reverse is an issue for any good quality folding propeller.

If you are really concerned about drag while sailing, avoid current Volvo Penta models. The curved blades don't fold well and they have huge drag for a folding propeller. The curved blades may have a lower noise and vibrations, if that is an issue e.g. due to too low clearance.

I have an older Volvo Penta 2 blade folding propeller, which is the same as Radice/Allpa. It is the cheapest in the tests, but still OK and I'm perfectly happy with it.

#9 briartrtpd..

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Posted 02 July 2010 - 07:38 AM

Kiwi prop

http://www.kiwiprop.com/

been using one for about 2 years now and haven't had any issues



http://forums.sailin...1

#10 Jono

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Posted 02 July 2010 - 09:25 AM

I have a similar hull shape Farr 36 footer. We remotored to a Volvo 3 cylinder 29 hp on a shaft drive several years ago. We added a Volvo 3 bladed folding prop and are very happy with it. Low maintenance, great performance, no drag issues. It is possibly a weed magnet but this may be due to is locatin very close to the rudder skeg and keelson. Great value too. And for resale everyone will appreciate the matched unit.

#11 Joakim

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Posted 02 July 2010 - 12:14 PM

Low maintenance, great performance, no drag issues.

Great value too. And for resale everyone will appreciate the matched unit.


How do you know there are no drag issues? Several tests have shown that Volvo 3 bladed (and the new 2 bladed) have much higher drag compared to any other folding propeller (even 10x more). Yes it has much less drag than a fixed propeller and its drag is hard to notice while sailing.

Why is it great value (very expensive!)? Why would someone appreciate a brand matching the unit? Volvo has clearly succeeded in marketing and I also wanted one, when it came to market, before the test results.

#12 DrewR

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Posted 02 July 2010 - 12:37 PM

My observations:

1) My 8 year old 3 blade Maxprop had some pitting due to electrolysis. Maxprop's customer service was superb, they quoted over the phone a price of approx. 10% of a new prop based on my description of the pitting. When they received it, they called to say that it was not as bad as they thought and it would cost less to repair. The tech who worked on it called me when it was done, described what he did, and then packaged it and sent it back. It was about a week turnaround time and it came back looking brand new and well under the original quote. That kind of customer service really stood out and made me a very happy customer.

2) Altho many people diminish reverse performance, yes its true 98% of the time the boat is in forward, but if I did not have the reverse performance I have with the Maxprop, my insurance company would not have been very happy a few years ago. We were on Block Island pulling in to fuel up, and a small localized squall or burst appeared out of nowhere. It took 110% of what my engine and prop had to keep from nailing a nice shiny 70+ foot sportfish boat, I missed it by maybe 1/2". So the reverse capability saved me from paying for one **very** expensive Awlgrip job. It turns out the boat had just been sprayed and the owner who was on board watching thought it was game over. This may be a rare case, but the cost of the Maxprop was paid back in spades in that one moment.

3) A good friend bought a Kiwi prop 2 years ago and loves it, except for one thing: when the engine is cold, he has no reverse, reverse just stalls his cold engine. When the engine is warm, he has no problem but when its cold, its stalls 100% of the time. He tells me there is no adjustment for reverse pitch, so he has to really warm his motor up before he sets off. Since hes on a mooring, its mostly not a big deal, but its something that I know would bug me. Other than that, he loves the thing, he went from a 2 blade fixed prop to a 3 blade Kiwi, and since hes got it, he's won his PHRF class 2 years running, well worth the 9 sec. hit in NE.

4) The Gori's are excellent props. I did a delivery 2 years ago on a big cat that had them, and the low speed was tremendous. We had a 24+ hr motor and the low gear worked great.

If I had to do it over, I would probably consider the Flexofold, but my experience with Maxprop would probably give the nod to them.

Just my limited observations...

#13 Mark M

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Posted 02 July 2010 - 02:21 PM

Old boat had a maxprop, and had head to head compared with identical boats with flexofolds, autoprops, gori (that was a stretch), marec, and of course fixed. Knew I wanted a maxprop on the new boat becuase the maxprop was the best choice for me. If I was more a motorsailor I'd have gone autoprop, and if I kept the boat on a mooring and not in a marina where I needed to back down, maybe a flexofold, but for me, a marina based sailor with a burnished baltoplate bottom done in the intest of trying to race, the maxprop was the solution.

New boat was to come with a flex-o-fold. I wanted a maxprop. Arranged with factory for paying the difference in price, no problem.

Boat shows up with flex-o-fold. they offer to refund difference, because "the flexofold is a good prop". Articles and references. It is a good prop, but I consider the maxprop to be a GREAT prop. No deal. got the maxprop ans switched.

Yes, the flexofold is very good under sail. It is good under power. No question on either of those, perhaps it might or might not have an edge and is cheaper. but then, you go into reverse, and all bets are off.

No prop anywhere backs down like a maxprop. They stop a boat faster than a fixed prop. Those duckbill style folders are trying to collapse themselves when backing down. If you're an all-out raceboat, get a duckbill folder and have ultimate low drag. But if you want to be sure you can stop your boat when you want to stop your boat, get a maxprop. Consider it a piece of modern art you put under your boat and accept that the price is because they know they can get that price; the props are worth it.

#14 crash

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Posted 02 July 2010 - 03:11 PM

If I had a sailboat...I'd want a prop that made it a better sailboat, not a better motorboat. After all the engine is an "auxiallary" power system, not the primary one....

I can attest to the great customer service Rockhead provides for Flexofold. I had a 2 blader installed on my J-109 (an early 2003 model that originally came with a different prop - that didn't always open!) after Rockhead helped me sort out what hull no. J-Boats made the switch on (hull after mine!)performance both under sail and under power was great. No issues backing down or stopping. Always opened...everytime. It was a great prop, and if I every re-prop my current boat (sold the 109) I'd buy another Flexofold in a heartbeat.

Crash

#15 RockHead

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Posted 02 July 2010 - 03:27 PM

Here's the efficiency curves per the Univ of Berlin study:
Attached File  Univ of Berlin Graph.jpg   977.3K   169 downloads

And the drag results:
Attached File  Berlin test summary NP.pdf   33.95K   89 downloads

#16 jerryj2me

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Posted 02 July 2010 - 04:07 PM

All useful information -
I see we got a lot of opinions coming from MA,
I hail from the South Shore (Norwell & Weymouth)
but am in S CA (Sandy Eggo) these days.

That aside - my old boat had a 2 blade flexofold and backing
was a minor issue. About the only time it might be an issue is killing speed
coming into the slip, and I can adapt to a new prop personality.

I see that the feathering props make more sense on a Saildrive, because they
align with the shaft, which is great forr the horizontal shaft of a saildrive.

Since I am conventional motor and shaft in the water to a prop strut I see the sense of a folder instead.

Hmmmm..
Any other suggestions here?
These things all take a prop zinc without any pain?
Anybody know a San Diego prop shop that deals with this sort of thing?

#17 Blackbeard

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Posted 02 July 2010 - 06:52 PM

All useful information -
I see we got a lot of opinions coming from MA,
I hail from the South Shore (Norwell & Weymouth)
but am in S CA (Sandy Eggo) these days.

That aside - my old boat had a 2 blade flexofold and backing
was a minor issue. About the only time it might be an issue is killing speed
coming into the slip, and I can adapt to a new prop personality.

I see that the feathering props make more sense on a Saildrive, because they
align with the shaft, which is great forr the horizontal shaft of a saildrive.

Since I am conventional motor and shaft in the water to a prop strut I see the sense of a folder instead.

Hmmmm..
Any other suggestions here?
These things all take a prop zinc without any pain?
Anybody know a San Diego prop shop that deals with this sort of thing?



I've owned 3 boats with 3-blade MAX Props over the last 26 years and have done multiple offshore passages (Hawaii, west coast, Tonga/New Zealand) on boats with Max Props.

Keeping a zinc on the prop is the most important maintenance item. For the last 5 years I have been using Petit's Barnacle Barrier zinc paint on the prop. The zinc based paint has extended my zinc life 2X. Changing the Max Prop zinc is easy enough if you are used to changing shaft zincs. I will be diving on Calypso this weekend to change both shaft and prop zincs. The only trick is not dropping the allen head zinc bolt. They are hard to find on the bottom.

Blackbeard

#18 owlslick

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Posted 02 July 2010 - 08:34 PM

The best bang for the buck is a two blade folding prop. Performance under sail goes way up, while not giving up any real performance under power.

Feathering props with 2 blades are approximately twice the cost of a 2 blade folding prop. The 3rd blade ups the price by another 50% over the 2 blades. The 3rd blade can have some advantage over a 2 blade which mostly comes into play in maxing out the capabilities. In general use a 2 blade does not give up much if anything to a 3 blade. In most cases a 2 blade feathering will get you the best value over a 3 blade.

One can make an argument for spending more if special circumstances require that prop performance under power be maxed out. I would pick a prop that best suits your expecations and your wallet. All the available props are good performers especially over a fixed prop. All the mentioned props have their virtues. I have used them all, each has its' niche, pick one that meets your expectations. I have some customer service issues with Gori. They had no interest in dealing with a failed prop. Any of the other brands mentioned have a history of good customer service through personal experience or heard about good responce about the customer service. Gori ( short version ) told me "f....k off and get a new prop", both here and their home office ( Denmark ). Gori gets a premium price ( good performance ), but had no interest in helping ( at my expense ).

#19 jerryj2me

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Posted 03 July 2010 - 05:59 PM

Based on what I am reading,
the folding prop seems to be where I am heading.

Feathering seems to make more sense on Sail Drive,
and since I am shaft & strut configuration folding seems to be
the path of choice.

Gori is out due to product support issues.

Now - 2 blade or 3 blade? Price difference is not
a big deal one way or the other.

If balance and vibration are a big issues, then 3 blade folder sounds right

Your thoughts?

#20 owlslick

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Posted 03 July 2010 - 07:11 PM

Based on what I am reading,
the folding prop seems to be where I am heading.

Feathering seems to make more sense on Sail Drive,
and since I am shaft & strut configuration folding seems to be
the path of choice.

Gori is out due to product support issues.

Now - 2 blade or 3 blade? Price difference is not
a big deal one way or the other.

If balance and vibration are a big issues, then 3 blade folder sounds right

Your thoughts?


2 blade folding props have no drag ( almost... not enough to measure ), make sure blades are geared ( a very good feature at minimal cost ), folding prop should not snag on anything Vibration not an issue when new, may creep in as parts wear, most mfg will rebush when excessive wear causes vibration ( check w/mfg )

3 blade folding prop... more complex in design, no real point unless there is an issue with hull clearance where a 3 blade would have a smaller radius for better clearance

2/3 blade feathering if serious motoring is expected and budget is not an issue, no real drag under sail, open blade design can snag lines etc

they all work nicely, read the fine print, you will not be disapointed

#21 FastBottoms

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Posted 04 July 2010 - 12:07 AM

Today I took the 3-blade Max Prop off Hula Girl and put the Martec 2-blade folder on. Hope they can find someone in Hawaii to swap 'em back. I told Wayne I was available and would even fly coach. :P

#22 JL92S

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Posted 05 July 2010 - 06:14 PM

we had a hanse 400 with a flex o fold 3 blade folding prop, good sailing performance and good speed ahead but bad prop walk and poor stopping and also some vibration but a pretty prop all the same. the GS54 i sail on has just aquired a 3 blade gori and the owner got gori to take measurements of the shaft because it was an odd size and make a prop special 3 blade prop that will fit the boat, i call that good customer service. it gives the boat 8.6kts+ in ahead and will stop the boat from 6kts to stop in a boat lengh with very little prop walk. from an IRC point of view the boat's handicap went down 4 points, a good optimisation as the prop is the lowest drag 3 blade folding prop. only issue is the price :(

#23 K38BOB

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Posted 05 July 2010 - 06:28 PM

Kiwi prop

http://www.kiwiprop.com/

been using one for about 2 years now and haven't had any issues



http://forums.sailin...1



any other input/experince with Kiwi prop?

#24 soling2003

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Posted 05 July 2010 - 11:02 PM

I personally like the max prop for reverse and when you put it in fwd, you don't have that "clunk" of the blades opening.
If you go with a folder, just remember, the best reverse action is when it is as square as possible, ie 17x17, 16x16, etc.

#25 allpiss&wind

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Posted 06 July 2010 - 07:10 AM


Kiwi prop

http://www.kiwiprop.com/

been using one for about 2 years now and haven't had any issues



http://forums.sailin...1



any other input/experince with Kiwi prop?

We've had one for 18 months now, love it. On a 34 foot boat, displacement about 4.5 tonnes, Volvo 2030 engine w prop shaft.

About a month after we got it, I hit a lump of floating timber. Prop seemed fine, so didn't see the need to check it (not unbalanced or anything). Had the boat slipped a couple of weeks back, and no slime or barnacles on the blades at all (just a tiny chip in one from hitting that lump of wood) -- but if we had damaged it, replacement blades are about $A100. In between slippings, we had a diver who was amazed at the lack of weed and growth on the prop compared with the rest of the boat.

Everything else about it is great. Stops us very quickly, great reversing power, and minimal prop walk -- just enough to get us into the dock neatly.

Other nice thing is no need for prop anodes (still need one for the shaft, of course). Our previous Volvo 3 blader was only about 3 years old, and a year overdue for replacement. And it had horrible prop walk. Saved $1000 on going for the Kiwi Prop too.

#26 allpiss&wind

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Posted 06 July 2010 - 07:10 AM


Kiwi prop

http://www.kiwiprop.com/

been using one for about 2 years now and haven't had any issues



http://forums.sailin...1



any other input/experince with Kiwi prop?

We've had one for 18 months now, love it. On a 34 foot boat, displacement about 4.5 tonnes, Volvo 2030 engine w prop shaft.

About a month after we got it, I hit a lump of floating timber. Prop seemed fine, so didn't see the need to check it (not unbalanced or anything). Had the boat slipped a couple of weeks back, and no slime or barnacles on the blades at all (just a tiny chip in one from hitting that lump of wood) -- but if we had damaged it, replacement blades are about $A100. In between slippings, we had a diver who was amazed at the lack of weed and growth on the prop compared with the rest of the boat.

Everything else about it is great. Stops us very quickly, great reversing power, and minimal prop walk -- just enough to get us into the dock neatly.

Other nice thing is no need for prop anodes (still need one for the shaft, of course). Our previous Volvo 3 blader was only about 3 years old, and a year overdue for replacement. And it had horrible prop walk. Saved $1000 on going for the Kiwi Prop too.

#27 DDW

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Posted 06 July 2010 - 01:06 PM

Since it hasn't been mentioned so far, I suggest you look at Autostream by Seahawk. They make folders and featherers. I just put an Autostream feathering on to replace the Variprop feathering. I have had Maxprop feathering, a CDI feathering (similar to Kiwiprop but 2 blade) on other boats.

I would not buy a Maxprop - fine product but dated and expensive, difficult to assemble. The Autostream is all duplex and 316 stainless steel, has replaceable bushings, can be adjusted for pitch over a wide range with a screw independently in forward and reverse, can be assembled RH or LH pitch, is easy to fit or remove, and costs significantly less than a Maxprop. In the size I bought, over $1000 less than a Maxprop, $1500 less than a Variprop, and at least as nicely made as either.

#28 Jono

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Posted 07 July 2010 - 06:03 AM

Per Joakim
I am in NZ. My Farr 1104 is old school with a small deadwood and skeg
Value - I priced Maxprop and Gori at the time and Volvo was way cheaper. At the time there were a couple of complaints locally with Kiwiprop (blades flexing?)and I couldn't be bothered.
Drag. I wanted a 3 blade for performance motoring with a young family when I needed to. I don't change props for races. The Farr is relatively easy driven and I keep it clean. I have had a fixed 2 blade prop on a previous boat. It is low drag enough for me.
Maintenance. I have had a Maxprop 2 blade prop on another previous boat and have some idea of mainetenance issues. The Volvo prop is way less.
So as a summary, I am very happy with the 3 blade Volvo prop on my shaft drive boat.

#29 jerryj2me

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Posted 17 July 2010 - 07:31 PM

OK, so I went with a 3 blade Flex-o-Fold prop.

Just arrived on the UPS truck yesterday.
My diver will go down Monday to install it.

Inspection of the shipped goods looks like a well
built prop - very sturdy and well cast-machined.

Stay tuned,will see how it performs shortly.

#30 jarcher

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Posted 21 July 2010 - 04:37 PM

Do any of these props have the ability to fold automagically, so that the crew does not have to manually turn the engine shaft to make sure they stay folded?

#31 RockHead

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Posted 26 July 2010 - 05:37 PM

Do any of these props have the ability to fold automagically, so that the crew does not have to manually turn the engine shaft to make sure they stay folded?


Geared folders do, as do featherers. Only old school ungeared folders need assistance.

#32 DEAD MONEY

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Posted 26 July 2010 - 06:01 PM

Go w/Geared folding/feathering and you won't be sorry. Older Martecs have NO gears and wear out w/too much "slopp". I have put Vari-Fold on 2 boats and have been extremly satisfied. Reverse is NO issue because it is Geared.

#33 Becalmed

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Posted 27 July 2010 - 05:26 PM

I currently have my Martec on and it pushes the boat fine and will push the boat fast enough for the kids to skim along on a wakeboard. It works a bit better than the Gori that was on before, but I believe that is because the smaller blades give some more revs and don't kick on the rudder as much. I have a fixed 2 blade that may go on if we go on a canal trip since it has a bit more brakes than either of the others. I've noticed some props work better on some boats than others, and finding the right one is 50/50 good luck and good planning. I've played with some of the newer auto/vari/flexo props and don't see enough advantage for the cost, and most owners have commented that they're happy but....
If you have a big enough motor, it doesn't matter so much, but if you had a marginal motor they would likely be a better deal than a repower.

#34 George Sessions

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Posted 10 February 2011 - 05:39 AM

I have an Autoprop. ABMarine had rebuilt the prop in 2007. In May of 2009 and 225 hours later a bladecame off. I sent it to AB Marine who sent it Buntons Marine in England. BuntonsMarine replaced the blade for $1500. I had the prop lubricated every sixmonths. I am always in deep water. It never touched anything but saltwater. Ionly go to Catalina and back. Other than the lost blade there was not anyevidence of damage or distress.

At the time Steve Armitageof AB Marine told me that losing a blade was a “rare occurrence” and that hedid not have an explanation for why the blade fell off. David Sheppard of Brunton'sPropellers Ltd, told me losing a blade is an [font=&#26032]
[font=Arial]an exceptional case”. Contrary totheir comments the prop has been subject to a recall for lost blades. If yousearch other support groups and blogs you will find many others that have lostAutoprop blades. It demeans their credibility to say otherwise.[/font]

[font=Arial]Although I enjoy the performance of my Autoprop myexperience with AB Marine and Brunton's Propellers has been extremelydisappointing. They are unwilling to stand behind their expensive product. Inall their replies I feel like I am hearing from a politician trying to avoidgiving a straight answer. I would stay away from anything that might need to beserviced by AB Marine or Buntons Marine (Varifold, Autoprop, Gori).[/font][/font]



#35 sailman

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Posted 17 February 2011 - 01:07 PM


Kiwi prop

http://www.kiwiprop.com/

been using one for about 2 years now and haven't had any issues



http://forums.sailin...1



any other input/experince with Kiwi prop?

I have had mine for two seasons now and have zero complaints. I did experience the reverse stall that another post mentioned, fixed it by moving the idle speed up about 100 RPM.




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