Maaate. If you have already bought the folding prop, you are going to be fitting it at your next slipping aren't you???

So, there is no point in saying anything if your old prop works well, other than, "Don't sell it!!" If the new prop is not right, you have a point you can go back to.

If the new prop DOES work well, the yacht can be configured for sailing/racing or cruising motor/sailing. (A valuable selling point.)

I am a cruising sailor and for me simplicity and low maintenance are key factors.

I am a big fan of fixed three blade propellors that have accurate pitching of the blades and are balanced and matched to the hull speed and horsepower of the engine.

Further, when the whips are cracking and the chips are down, (Oh shoot, we just lost the rig!!!) the three blader will get you out of the crap better than anything else, fouled or not.

The only caveat on fixed three blade props is that the prop shaft MUST be able to be locked when sailing only. If it is left to spin when sailing, it will act like a governor on your sailing speed, wear your shaft bearings, seals and gearbox out unnecessarily.

It has been proved that a locked 3 blader induces less drag than a freewheeling one.

But that is not the end of the debate.

An efficient propellor is a precision piece of engineering, made more so if it is folding or feathering. To hang such an item in sea water where it is subject to electrolysis and marine growth severely challenges engineering principles and dictates a strict maintenance program.

If you want to race, fold or feather, but definitely fix on a regular basis.

If you want to cruise, fix once, then just go enjoy that world that is out there.

No I don't have a new prop yet .... I'm looking at the 3 blade feathering Max prop.?...it's $4000 and made in Italy......I chatted to a guy on the cairns slip he said its worth every cent and far more effective than any other type of feathering props......im looking for feed back that's all......

I have a free spinning gearbox which gives me the ****s as I have to lock my prop when sailing from down in the engine room..... For 5 years I have thought about how to solve the problem and the best answer that comes to me is a folding prop. As for wearing a bearing on a free wheeling, what difference does it make if your sailing or motoring when your prop shaft is spinning? How long do bearings last on motor vessels? My bearings are 30 years old and still have life left.
I have decided to slip and antifoul and consider more about the decision futher into the new year

www.pyiinc.com/max-prop.html

southace said...
I have a free spinning gearbox which gives me the ****s as I have to lock my prop when sailing from down in the engine room..... For 5 years I have thought about how to solve the problem and the best answer that comes to me is a folding prop.

Is your gearbox hydraulic (ie has a torque converter like an auto box in a car) or maybe the clutches are controlled hydraulically?

or

Is your gearbox mechanical with cone clutches or similar that are engaged directly by the control lever?? Locking the shaft while sailing with type of box of course is simply a matter of having it in gear while sailing.

I must admit, that did not immediately occur to me when I had my first yacht.

BTW Thanks for the link to Max Prop.

If it is difficult to lock the prop and stop it freewheeling, then the Kiwi is probably your best bet as it performs well with the shaft unlocked. AFAIK most other folders or featherers need to be locked when sailing.

I had a Kiwi in my S&S34 and was very happy with the performance. At least half a knot better speed.

I have just replaced my prop with a 2 bladed folding and it is great. Cost about $1500.
A mate put a Kiwi on his S&S34 with a new Volvo sail drive and it hasn't worked out too well. Can't get the speed he should. Further adjustment might fix it.
A normal fixed prop I reckon is at least a 0.5 kt penalty when sailing, and more thrust under motor so you should get 0.5 kt better under power.
Personally I can't see the value in a $4000 prop.

I have heard very good things from other cruisers about Maxprops, I dont think you will go wrong if you want to spend that much. I just fitted a new 50hp beta to my 43 footer in Langkawi and matched it with a 3 bladed slipstream stainless folder built in aus. I had a 2 blader on my last 29 footer and was also very impressed. Heaps of drive ahead with the 3 blader I am VERY happy with it. Reverse you do have to give a few extra revs but its fine. Cost $2400 for 17" sent to Langkawi and they were very good to deal with. Good luck

cisco said...
Check the article in the latest Cruising Helmsman re antifouling on props and sail drives.

I never buy it. I just skim them in the shop.

Just give us the skinny on it you bastard! Next slipping I'm going to just mirror polish and maybe coat with stove black.

I love my folding 3 blade volvo penta on my saildrive.
Straight after cleaning and greasing it closes no mater what you do,
but depending on the degree of grease vs foul/growth, if it does not close properly it means anywhere between 0.5-0.7 of a knot of boat lost or gained depending on your perspective.
I always pop it in reverse after turning off the motor, sorts it instantly.
Makes a massive difference - Absolute no brainer - folding.

I hear some folding props dont grip well or quickly in reverse - I have no such issue with the volvo 3 blader.

Just read one of your earlier posts about your spinning prop stopping you from sleeping - A word of warning , the folding prop will still spin if not collapsed ie if there is significant growth on the prop teeth there is resistance to collapse.
So if you motor to a mooring , shut down the motor and cant slip the gearbox into reverse you'll eventually have an issue with the folding prop too, spinning in the current if it has not collapsed.

southace, I've got a Kiwiprop (3 blade feathering) on my Dunc 34 - very happy with it.

Can vouch for the extra 0.5 to 1 kn under sail. Selection of reverse stops spinning after shutting off the engine and once its stopped it will happily stay that way in neutral on the box - I can't lock the prop on the saildrive.

Thrust under motor (+25yr old 18hp Volvo saildrive) is completely incomparable to old fixed 2 blader - especially in reverse. It used to always be a concern pulling up in my pen with a stiff seabreeze wanting to ram us into the jetty, now a short burst in reverse has us stationary in the pen in about a quarter of a boat length at worst.

Only downside is, I agree with Ramona that fouling has a more pronounced effect on performance than it did with the fixed prop...but when the clean performace is so much better, the fouling has to be very bad for the benefits to be outweighed.

Interesting that MorningBirds mate had problems with the Kiwi on SS34, which are very similar to the Duncs. Pitch on blades is variable so if you are not getting desried speed it should be possible to adjust to suit. The manufacturer (John Blundell) is a very helpful bloke and will work through those issues with you if you need. In my case, I have never altered his recommended pitch settings as I get my 4 to 5 kn (depending on how strong the wind is that I am punching into) well before the engine starts complaining and getting smoky (no tacho so I don't know what revs that is at, but an happy / unhappy engine is pretty obvious).

Mine cost about $1800, very good value for money in my book.

Yes on 3/4 throttle at 1750 rpm I get about 5.5 knots, I cruise at 1600rpm which gives me 5 knots this is in calm conditions with a clean bum and my stranded fixed prop.

Will up date when I fit the maxiprop in future.