I have a 1984 Freedom 32 with the usual Yanmar 3GM and what I believe is the original two blade 14" propeller.
I am debating a 14-15" three blade MaxProp, Brunton Autoprop or a Gori to give me better performance, self feathering under sail, and better “in reverse” performance.
All seem to cost something between $2500 and $4000…Does anyone have a recommendation on one of these (or other) props and where to get a really good price
All comments much appreciated
Richard
smith.richard968@gmail.com
Hi, I have a 16 inch kiwi prop. I think you can still get them for under 2k. After 4 years and approx 1000hrs I rate it about a 7/10. Compared to your current prop you will find it makes a huge difference. The pros are it drives Freeform very well. I regularly motor at 6.5k and above. It punchs the boat into a chop very well. I think you would find a big improvement over your current prop. Reverse is excellent when greased well ( more in a minute ). Matched very well to my 3gm30f. And when feathering obviously has the advantages of a feathing prop. John at Kiwi prop is very good to deal with.
The not so goods are: needs regular greasing. If you dont keep the grease up the blades fail to rotate properly when put in reverse and overload the engine (i see they have a newly designed blade trying to solve this problem. )This isnt much of a problem for me as i have a hooka and dive and grease blades regularly. I also find prop will auto rotate if not put in reverse intially to stop it, then back into neutral (often wont feather by its self which is my biggest gripe)Even though the blades are tough they can get pretty beat up im on my second set although 2 of the blades I could have filed to be useable (are now spares) In fairness the Malacca Straits are full of lots of stuff that knock your boat around including the prop. In a way the blades can be sacraficial protecting other parts of the drive chain and are easy to replace underwater I believe this is a good thing as I know a number of people in Asia that have bent propshafts etc.
I have no idea how a kiwi prop compares to other feathing or folding props. Obviously a major part of my decision was it was considerable cheaper than other feathering props.
Overall quite happy but would possibly try flexofold next time sacraficing abit of the the reverse stopping power for better shaped blade providing a little more thrust and better fuel economy ( I think… dont know)
Cheers Dale
Freeform F32.
Freeform.
Have a Kiwi prop on an F35 (UK) cat ketch. It’s a great improvement in every way over the two 2-blade folding props and the fixed (original) 2-blade ones I have used before, most especially in reverse. I’ve only had it one season, so far, so couldn’t say how well it would last, but it is in fine condition after 900 miles this summer. The UK agent is very helpful about fitting and maintenance; but that’s a local thing.
The beautiful Gori folding 2-blade prop was very long and I had to cut a lump off the rudder to get it to close without fouling. It didn’t work well in reverse.
On my Hoyt 32 I have a 3GMD with a KM3-A transmission, 2.61 gear ahead, 3.16 gear astern. The original 2 blade (from the factory) was a 14" diameter 14" pitch right hand (1" tapered shaft.) I replaced that with a solid 3 blade prop that was a wildly large-bladed 14 dia x 15-ish pitch, which was too much, it lugged the engine slightly (I still have it as an emergency backup.) My present 3 blade feathering prop is 14" diameter but pitched a bit less, 13-ish inches maybe, and it seems perfect.
No matter what you get I think that you’ll like the result. I started with the original 2 blade, switched to the overly large 3 blade then to a 3 blade feathering prop (Cruising Designs - no longer made.) The 2 blade was “not good, not bad”, fairly low drag but vibrate-y and not particularly powerful. The big solid 3 blade was fabulous under power, especially in reverse, and perfectly smooth, but under sail it was like dragging a sea anchor. The feathering prop is 90% of the solid 3 blade under power, very smooth, but it has added around 8 to 10% to my speed under sail, sometimes more. I don’t think you’ll get as much sailing improvement going from a 2 blade to a feathering prop as I did going from my giant 3 blade to the feathering prop, but I also doubt there is any other improvement you could add that would get you as much gain. Powering should be better than your 2 blade, much more “punch” and a tiny bit more speed, but reverse should be very noticeably more powerful.
Pricey, yes, but a feathering propeller is a REALLY nice improvement to any sailboat.
Thanks Rick (and the others who have posted). Your info is invaluable…
I was just contacted by the KIWI representative here in Canada and their recommendation is a 16" feathering prop.
The only caveat was that if there were any clearance issues, the prop size could be stepped down to 15" or 15.5" but on the F32 (Hoyt) there is an enormous amount of clearance between the prop and the keel.
The price of the KIWI is $1500 which is by FAR the best price I have found…
Richard
Prop Update:
I recently found a comparision study of virtually all the feathering and folding props that are on the market in the US and Canada.
The study was sent to me by FLEXOFOLD along with their recommendations for the Freedom 32… They suggest a 16" two blade folding prop. Its performance is IDENTICAL to the 3 blade unit and better, its price is $1200 delivered to my door from the manufacturer in Holland.
The comparison study did compare the Maxiprop, Gori, Kiwi and Variprop among others: I’ll post a link to the study shortly
I’m going to go with the Flexofold and that said, prop walk is minimal and performance in reverse is exceptional. Thanks all for your help.
Richard
TEST, Yachting Monthly (UK), May 2009 - pdf
Hi Audiguy,
Old thread I know, but the subject matter is current for me. I am wondering if you ended up purchasing the Flexofold 2-bladed folding prop? If yes, what is your opinion of it?
I purchased one last year, mounted it without issue but upon running it the boat almost vibrated apart. That sounds extreme I know, but it was really that bad. The manufacturer immediately said the key was causing the issue that it certainly could not be their prop, despite the fact that the engine and coupler were realigned after an engine rebuild just a couple of years prior and the fixed 3-blade prop did not have any vibration whatsoever. As a matter of fact, it’s the smoothest set up I’ve ever had. I switched back to the 3-blade prop for the remainder of last year.
Two weeks ago, since the marina got their hoist strap caught in my 3-blade prop and bent it, I modified the keyway and remounted the flexofold prop. The key was easily a half inch away from the radius and the hub went back to the mark as it should, as it did the prior year. Once again I move the boat from the launch and the boat is vibrating like crazy.
My engine mounts are solid, feeler guages prove the coupler alignment to be within .001, the total runout of the prop shaft is under .002. The stut is very solid and the cutless bearing is snug, and I have no clear reason there is anything wrong with the prop itself. I cannot find any issues so that leads me to beleive that I am getting shaft whip.
Odd about the vibration. If it doesn’t happen with your previous prop, but does with the Flexfold, then either there are two components of the old system which are individually out of balance, but together are perfectly balanced (unlikely), or else there is something unbalanced about the Flexfold. The key would have to be pretty large to cause noticeable imbalance. So probably it’s the propeller, whatever the manufacturer says. Does it unfold symmetrically? If one blade didn’t unfold fully, that would certainly cause your problem. Another possibility is differences in the two blades, either pitch or weight. Personally, I would return it for a check on the balance, as there is little likelihood of any other cause.
Hi Castaway, thank you for your thoughts!
I agree with you, but I have found them (flex-o-fold) less than helpful. Any question asked that can be misconstrued as a prop issue I receive an answer about things I’ve already eliminated and informed them about, it’s an endless loop. They did offer to rebalance the prop at no cost, but of course it’s currently under water on the boat. By the time I haul out, have my old prop fixed and remounted, ship the flexofold back at my expense, have it returned at my expense, haul the boat again to remount it, I’ll almost be at the cost of the prop. This is one of those no-win scenarious I’m afraid.
In reality, while I agree with your logic (they’re the same thought’s I’ve had), when in reverse it is as smooth as can be (conflicts with: “Personally, I would return it for a check on the balance”), odd. My only thought on that is that maybe in reverse the rpm’s aren’t such that the prop blades are resting on the shock absorbers which would tell me that one shock absorber may be thicker than the other leading to the shaft whip when in forward. In essence I’m thinking it may have one blade not exactly on the same plane as the other in forward causing the shaft whip (indirectly may confirm your question: “or else there is something unbalanced about the Flexfold”). I have no way to test for that however without hauling the boat out, nor do I know for certain that the result of that would be a vibration anyway. I know, there are contradictions in this paragraph thus the dilema.
The prop itself is a beautiful piece of work, with a fantastic gearing design which always keeps the blades in unison (answers: “Does it unfold symmetrically?”). While on the hard, when I open the blades manually, they always have a gentle steady movement closing themselves back up, It’s quite pleaseing lol (sorry, having a machining background I appreciate stuff like that). All in all vibration aside, the prop moves the boat very well under power forward and reverse, with virtually no noticable prop walk. In flat water at 2000 rpm I’m cruising at 6.1 knots, 3000 rpm 7.2 (into the wind on my only test at that rpm). Surprisingly there is minimal vibration at 3000 rpm but I don’t like to run at that rpm for long, the engine sounds best at 2800 but vibration is unacceptable there. Under sail, I feel like I’m sailing downhill compared the the fixed 3 blade I was using.
I am hoping someone will confirm that yes, a folding 2-blade prop can run smoothly, but in re-reading Ricks post above he may have already implied that. I guess I’m going to bear with it for the summer since I’ll mostly be sailing locally and go over everything in the fall or spring and change out the cutless bearing too just to be further certain.
Sorry for my babbling post! Good thing I like a challenge.
Have you checked the minimum tip clearance, which might be different for the two propellers?
Or they might be different overall diameters so one has a reduced clearance.
A fixed prop might not like too small a clearance, but being solid would not vibrate, whereas a flex
prop might be flexed by some sort of back pressure effects each time a tip passes too close to the
hull, leading to vibration.
Just a thought.
Hi Rodent, great thought, I appreciate it. Since the blades on the folding props actually sit about 4" more astern than the fixed prop blades, I have almost 4" between the blade tip and the hull.
I looked into a flexifold prop last year. This is what they recommended for my F32.
With a Yanmar 3GM ( max. rated 22 hp / 3600 rpm, gear reduction ratio 1:2,61 ) we would recommend a 2-blade 16x12R propeller for your Freedom 32 Sail.
The price for a complete 2-blade 16x12R Flexofold with hub for ISO / SAE standard shaft is USD 1.215
Is this the same as they recommended for you?
Yes that is the same they quoted and I purchased. I love how the boat moves with it, I just can’t stand the vibration that started after mounting it. The same thing occurred last year. I installed the prop and there was much vibration so I had the marina haul me back out a few days later, removed the prop, double checked that it was mounted as per instructions, I also checked run out of the prop shaft, there was none, the cutless bearing was snug. I remounted the prop per their instructions, went back in the water but there was the same vibration so I had them pull me out again and put the fixed 3-blade back on for the remainder of the season. When the marina was taking me out for the winter their strap was caught in the 3-blade prop and bent it. I did not have it fixed so this spring I went through looking for issues related to vibrations again but everything checks out properly, so for now I have to live with the vibration. I’m not saying that you avoid their props, but I am saying that you may want to consider the action. Flex-O-Fold will not entertain the idea that any of their props could have some sort of manufacturing issues, even incidental issues.
I’m pretty happy with the Maxprop on our F32. Seems very well engineered and has worked flawlessly.
I do grease it annually. Very simple.
When getting ready to lift in spring and fall i put florescent zip ties in the toe rails marking the lift points. So far so good.
I will be looking at propellor options for my Freedom since I have to repower.
I reviewed suggestions here.
Seems like there were issues with the flexfold.
Did those get resolved?
Also, which Maxprop did anyone end up using.
Thx
FWIW,
I got a slipstream stainless 2 bladed folding prop recently. I had a fixed 2 blade prop. I like the new one better seems in my limited experince it does seem to back better. I can not really discern a difference in forward. Seems to work fine in my limited experience.
Regarding other low cost options, I am a big fan of the Campbell sailor propeller and have purchased my second after I bought my Freedom 35’ which came with a worn out factory Max prop. Practical sailor’s testing reflects my experience with these Campbell Sailors which is that they have a high thrust under forward power, improved reverse thrust (but not as good as a Max prop) and low drag under sail. For me, having the reliability and durability of a fixed prop with NO moving parts underwater to wear out is more important that a small amount of drag under sail (which I can barely notice).
It is surprising how much more forward and reverse thrust the Campbell has compared to a Michigan Wheel of the same diameter and pitch.
If you decide to go with a folding prop I would shy away from the Max prop which has gaps between the leading edge of the blade and the hub which make them vulnerable to catching and dragging seaweed and fishing line in the gap.
If anyone on this list would like to look at my set up I am hauled out for the winter in Salem, MA.
Mark K
S/V Encore
Freedom 35’