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02-04-2011, 04:02 AM
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#1
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Ensign
Join Date: Jan 2011
Posts: 6
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I have read all the revievvs and been to all the shows, but we all know that actual use is the best way to evaluate a product. I have a 51ft Idylles which will finally be ready this season. Love the security in reverse of the fixed I always had. Prop walk is bad with a fixed prop on a 51 but I have seen some awful scrapes in full marinas by peaple with feather / fold etc. props. The fixed was also nice when current on the nose can be an isssue. This is the last expensive purchase I need to make. Anyone with a similar size s/v who has found a fold/feather they like please feel free to comment. Just so you know as I said I have read it all so I don't need a refresher course. Sorry if that sounded rude, but I really want some hands on lots of blue water advice. Thanks Nelson S
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02-04-2011, 11:13 AM
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#2
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Admiral
Join Date: Oct 2004
Posts: 3,067
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Quote:
Originally Posted by Lazypalm
I have a 51ft Idylles which will finally be ready this season. Love the security in reverse of the fixed I always had. Prop walk is bad with a fixed prop on a 51 Thanks Nelson S
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Hi Nelson,
Good questions! One question back, why would one change from the understanding that a fixed prop delivers more 'OOMTH" than a folding prop?
My experience tells me that the advantage is mainly the 'Less drag factor' when sailing.
The disadvantage on day one,is the price. The folding prop I would like on the 51 Idylle would be the Max Prop, the 22" VP Which can be adjusted without taking it to pieces - can be found for less than $3,852.80.
Richard
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02-04-2011, 12:43 PM
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#3
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Admiral
Join Date: Jul 2004
Posts: 2,098
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Nelson, I know just what you mean. We had an Autoprop on SV Watermelon, and we ran into trouble with it once in Papua New Guinea. It's in our logs Sailing and cruising in Papua New Guinea, but I'll quote the excerpt here.
Quote:
Ron wanted to visit Namoai Bay (Wanatonoli Bay) on the eastern end of Sariba Island because it was the site of an American Catalina Base during WW II and there used to be seaplane moorings here. I can understand why it was chosen, because the bay is totally protected from wind and seas on all sides. If it weren't hideously deep it would be a perfect hurricane hole. The kicker is that to get there we had to go through Sawa Sawaga Pass - a very narrow pass with a current that can run 7 knots at full flood or ebb. Tide tables don't give a time for the slack tides, so we guessed and were wrong. Going with the current to get to the bay wasn't too bad, although surfing through this narrow pass isn't my idea of a thrill. Ron asked me how I liked it, and I asked him if he had heard me yelling "Whoa, horsey" at the top of my lungs as we slip-slided through. As lovely a place as it was, the anchorages weren't good, so we left the next day, going back through the pass. The tide was with us, but to our dismay the current, which should have been with us, wasn't. Now here was terror. We got through the pass, heart in my throat, and Peter said "okay, Jeanne, the worst is over, we're through". Since I had had the engine at almost top revs, I eased off on the throttle a bit, only to see us going backward toward the pass. It took us another 15 or 20 minutes of heart-thumping motoring at almost top revs before we broke the grip of the current and started moving forward again. We got to a lovely anchorage and I announced that it was going to take at least two days for my adrenaline level to go down enough for us to continue.
After much thought, I think that our feathering prop was the problem. Since we were doing fine until I eased the throttle, I think that with the slower revolutions of the prop the extreme current caused it to feather slightly, reducing its effectiveness and bite. I assume that the force of the current flowing over it was greater than the force generated by the revolutions of the prop. Until we increased throttle the prop blades weren’t at their most efficient angle to the water. Something to keep in mind should we ever find ourselves in such a place again.
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We bought the prop in 1988 or '89, and by the time we got to Australia in '93 there was some electrolysis affecting the moving parts. We sent it out for service and when it came back the tail hub was replaced with a special zinc in the cone shape of that hub. Apparently we weren't the only boat that had had problems with electrolysis and so they changed the design. It made a better zinc, but the fellows at the yard installed the blades backwards. Fortunately it was obvious when we tried to back out of our slip the first time. We had to be hauled again to fix the props. Such a nuisance.
Though it did, indeed, reduce drag, learning how to use it was different than using a fixed prop. Simply recognizing that one had to goose the throttle higher with the folding prop was a change in my suite of habits - those actions that bypass the brain and are performed by the muscles with minimal lapses. When we sold the boat we replaced the folding prop with the fixed prop it had come with - the new owner was a rank amateur and we didn't want him to make too many mistakes before he became experienced with sailing and boat handling. After 20 years with the folding prop, I was surprised at how much power the fixed prop had compared to our folding prop.
We had some cruising friends on a boat similar in size to yours, and they extolled the benefits of their variable pitch prop. Very experienced sailors and cruisers.
I hope this helps a bit.
Jeanne
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02-04-2011, 04:25 PM
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#4
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Moderator
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
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This might help:
On our (54 ft 30 Ton boat) we considered a variable pitch prop but didn't have room for it in the tight aperture between rudder and boat. It is such a tight space that to put on or take off a regular Michigan wheel-based fixed prop (most of what you'll find on US boats with fixed props) would require moving the (1500 lb) engine forward off the mounts OR dropping the rudder (not going to happen) unless we did a hub modification to reduce the 5-1/4" hub down to 4". So we went looking at other options.
Lucky us to have these problems! We ended up with a Campbell Sailor fixed prop that reduces prop walk in reverse due to sculpting of the blades, does more with less (smaller diameter for same thrust) and has been a great prop to own. Same price range as a standard fixed prop. Link to vendor.
Our blog post on this LINK
Pic of the prop--
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02-09-2011, 04:55 AM
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#5
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Ensign
Join Date: Jan 2011
Posts: 6
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Quote:
Originally Posted by MMNETSEA
Hi Nelson,
Good questions! One question back, why would one change from the understanding that a fixed prop delivers more 'OOMTH" than a folding prop?
My experience tells me that the advantage is mainly the 'Less drag factor' when sailing.
The disadvantage on day one,is the price. The folding prop I would like on the 51 Idylle would be the Max Prop, the 22" VP Which can be adjusted without taking it to pieces - can be found for less than $3,852.80.
Richard
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Rich thanks for the input. The plan is to take a year or two off, rent out the house and take off for Panama and so on. I just wanted to have the benefit of extra speed when under sail. I also don't want to lock the shaft because that also cavatates wash behind the prop in front of the rudder. The shaft noise and the tranny spin also makes me nuts after awhile. I may wind up with a new fixed after all, but since I do plan on a lot of blue water miles I wanted the few extra knots from the fold Prop.
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