What prop should I buy
- Thread starter bigtyme805
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ted_reshetiloff
Contributing Partner
I spent 1400 from www.pyacht.com for my 2 blade maxprop feathering prop 15". The 3 blade was going to about 2500. Look here for the best maxprop pricing I have seen.
3 Blade feathering from 12" and up:
http://www.pyacht.net/cgi-local/Sof...ade.htm?L+scstore+pwvc3456ffac85ac+1183113398
2 Blade Feathering from 12" and up:
http://www.pyacht.net/cgi-local/Sof...ade.htm?L+scstore+pwvc3456ffac85ac+1183113398
3 Blade feathering from 12" and up:
http://www.pyacht.net/cgi-local/Sof...ade.htm?L+scstore+pwvc3456ffac85ac+1183113398
2 Blade Feathering from 12" and up:
http://www.pyacht.net/cgi-local/Sof...ade.htm?L+scstore+pwvc3456ffac85ac+1183113398
Thanks for the links, Ted, and once folks look at the hub for the original Maxprop (nowadays called the "classic") they will see why this particular version can have a smaller diameter than its competitors. Thinnest Hub.:nerd:
Downside, and the other reason we went with Martec beside the price difference, is that resetting the pitch on the "classic" Max requires dissassembly and from watching the yard guys actually do this --resembles four-handed dentistry.
If starting over, I would probably buy the Kiwi that Shaun installed. When the difference is over a thou...
And... the Maxprop sellers are coasting on 30 year old amortized-out design and tooling -- I personally believe that they are charging way too much.
Just my opinion, and worth about that much.
Loren
Downside, and the other reason we went with Martec beside the price difference, is that resetting the pitch on the "classic" Max requires dissassembly and from watching the yard guys actually do this --resembles four-handed dentistry.
If starting over, I would probably buy the Kiwi that Shaun installed. When the difference is over a thou...
And... the Maxprop sellers are coasting on 30 year old amortized-out design and tooling -- I personally believe that they are charging way too much.
Just my opinion, and worth about that much.
Loren
Regarding efficiency, I believe the two blade is not more efficient than a three blade. One blade on a two blade is in turbulence, and only one pushes. On a three blade, two are pushing, and one is in turbulence. I'm not an engineer, but have come to this from reading several different sources. Here are a pair of links with some prop 101 info:
http://www.westbynorth.com/Choosing.aspx
and then:
http://www.a1discountprop.com/propinfo.htm
I was very price limited, and ended up going with a fixed three blade. For cruising, this seems to be a good solution.
.
http://www.westbynorth.com/Choosing.aspx
and then:
http://www.a1discountprop.com/propinfo.htm
I was very price limited, and ended up going with a fixed three blade. For cruising, this seems to be a good solution.
.
2 versus 3 blades
I certainly am no engineer; my comment about efficiency came from some reading I had been doing because of this thread. I too am looking for a new prop.
The article I read (can't come up with the link) referred to the turbulence not from the keel back to the prop, but from the distance between the two props. Each prop is turning in the wake of the prop ahead of it. The author said that a single blade would be more efficient, except for the balance issue.
Having no basis to make a judgement on my own, I was merely parroting what I have read.
Interesting how one can find divergent expert opinions.
I certainly am no engineer; my comment about efficiency came from some reading I had been doing because of this thread. I too am looking for a new prop.
The article I read (can't come up with the link) referred to the turbulence not from the keel back to the prop, but from the distance between the two props. Each prop is turning in the wake of the prop ahead of it. The author said that a single blade would be more efficient, except for the balance issue.
Having no basis to make a judgement on my own, I was merely parroting what I have read.
Interesting how one can find divergent expert opinions.
Hi Rod,
prop stuff is a pickle, and I have found it really hard to nail this stuff down. The article you are talking about sounds interesting, and there might not be a single right answer. Back of my head I want to say I also stumbled on something once talking about how the best efficiency is a single blade, but then there are some other problems that keep it from working. Wish I could find the article for grins.
I would have loved to have gone with one of the 3 blade feathering props, as it seems pretty unanimous on the performance/drag benefit. My budget just couldn't, and I ended up picking up a used 3 blade from the marina I haul at. They actually specialize in power boats, and only have a few sailboat customers, but their power boat expertise was helpful. I had a pretty amusing time listening to the owner talking with a big prop shop in the area about repitching my prop and diameter and what the computer models said. The model wanted to put something like a 17 inch wheel on Emerald (she needed a 13x12.5x1). The jist of the conversation between the marina and the prop shop was along the lines of, Marina: "you know that computer model isn't worth a damn, now let's talk about reality", and the response was "yep"
I ultimately pitched if off other folks experiences with the same engine and boat. It works great, but would have taken forever to get there if I didn't have the inside track on my specific installation (thanks Glyn!).
If you really want to stir up a hornet's nest, just get into whether you should let if free wheel or lock it in place while sailing
.
prop stuff is a pickle, and I have found it really hard to nail this stuff down. The article you are talking about sounds interesting, and there might not be a single right answer. Back of my head I want to say I also stumbled on something once talking about how the best efficiency is a single blade, but then there are some other problems that keep it from working. Wish I could find the article for grins.
I would have loved to have gone with one of the 3 blade feathering props, as it seems pretty unanimous on the performance/drag benefit. My budget just couldn't, and I ended up picking up a used 3 blade from the marina I haul at. They actually specialize in power boats, and only have a few sailboat customers, but their power boat expertise was helpful. I had a pretty amusing time listening to the owner talking with a big prop shop in the area about repitching my prop and diameter and what the computer models said. The model wanted to put something like a 17 inch wheel on Emerald (she needed a 13x12.5x1). The jist of the conversation between the marina and the prop shop was along the lines of, Marina: "you know that computer model isn't worth a damn, now let's talk about reality", and the response was "yep"
I ultimately pitched if off other folks experiences with the same engine and boat. It works great, but would have taken forever to get there if I didn't have the inside track on my specific installation (thanks Glyn!).
If you really want to stir up a hornet's nest, just get into whether you should let if free wheel or lock it in place while sailing
.
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