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keep in mind that props don't drag all that much anyway. according to
the MIT data, even a fixed 3 blade only pulled 170# on a boat at 5 knots, or about the equivelent of 2-1/2 hp. Not relevent to the issue. It may mean that the autoprop wouldn't be worth the cost, don't know, haven't bought one, don't plan to. Although we will be replacing WindWalker's prop this next year, it's likely going to be a fixed prop, simply because of cost. Some possibility of a maxprop, but that's only if we think the cost is affordable. but, it very much was the question asked in the beginning of this tread. an auto-prop is NOT a folding prop -- which gives the least drag as compared to a fixed prop -- and is NOT a feathering prop in any sense in which the word feathering is used. an auto-prop is a variable speed transmission. in addition, in the context of the title of this thread, NO a folding prop is not much use except to racers. The drag of a fixed three blade prop ain't all that much, the drag of a fixed two blade prop is much less than a three, and a fixed two blade aligned behind the keel has even less drag. the difference in drag between a fixed two blade prop aligned behind the keel and a folding prop is like picking up nickles on the street. -- Jim Richardson http://www.eskimo.com/~warlock Does Emacs have the Buddha nature? Why not? It has bloody well everything else |
JAX, Just to get something clear, are you talking about the prop shown under "Diagram" on the Autoprop website- http://www.autoprop.com/ ? JAXAshby wrote: Fact remains, the blades on the autoprop swivel to be inline a corkscrew surface can not be "inline" with anything except another corkscrew surface with the shaft, and present less drag than in the forward or reverse direction, how is that not feathering? |
Subject: What are the pros and cons of a folding prop?
From: Jim Richardson Date: 09/03/2004 19:51 Pacific Standard Time Message-id: On 03 Sep 2004 11:58:59 GMT, JAXAshby wrote: oh, jim, it has been explained in terms even a 10 year kid could understand. get your older sister to explain it to you. Well, I don't have an older sister JAXAshy, so perhaps you can try again. How is the autoprop not feathering? The blades swivel to be inline with the axis of the shaft, and present less drag than in the forward or reverse config. How is that not feathering? Jim, the issue is not whether the autoprop can be called a feathering prop. The issue is, how long can Doodles keep you arguing the point. Shen |
On 04 Sep 2004 13:06:10 GMT,
JAXAshby wrote: Why do you insist on claiming I bought an autoprop? because no one but someone who threw $2,200 on the table for such a tiny improvement in forward speed would write the junk you write. an auto-prop is a variable speed transmission, not a feathering prop. the prop is a *transmission*? OK, that's funny. But given your accuracy in other areas, I guess that kind of claim is to be expected. -- Jim Richardson http://www.eskimo.com/~warlock "$HOME is where your dotfiles are" - Gym Quirk |
On 04 Sep 2004 13:08:18 GMT,
JAXAshby wrote: Then why did you post a definition of feathering, which fit the autoprop? it does not fit. not even close. and if you had not blown $2,200 on a prop hoping against hope you could make your boat *sail* faster you would know the difference. Did the dealer tell you you could pass Island Packets and Westsail 32 if you bought an auto-prop? I didn't buy one JAXAshby. I simply wanted to know what you meant by calling it a non-feathering prop. Alas, I should have known better than to expect rational discourse from you. -- Jim Richardson http://www.eskimo.com/~warlock 'Windows' really does make a fine swear word, representing all that's taboo and awful - just like '****', '****', etc." -- Mark Hughes, sdm |
On 04 Sep 2004 17:15:55 GMT,
Shen44 wrote: Subject: What are the pros and cons of a folding prop? From: Jim Richardson Date: 09/03/2004 19:51 Pacific Standard Time Message-id: On 03 Sep 2004 11:58:59 GMT, JAXAshby wrote: oh, jim, it has been explained in terms even a 10 year kid could understand. get your older sister to explain it to you. Well, I don't have an older sister JAXAshy, so perhaps you can try again. How is the autoprop not feathering? The blades swivel to be inline with the axis of the shaft, and present less drag than in the forward or reverse config. How is that not feathering? Jim, the issue is not whether the autoprop can be called a feathering prop. The issue is, how long can Doodles keep you arguing the point. Yeah, the old adage about mud wrestling with a pig springs to mind... -- Jim Richardson http://www.eskimo.com/~warlock Windows XP... now runs all your favorite viruses. |
jim, the word transmission was used a metaphor. the auto-prop changes its
pitch to match engine power with boat speed. kinda. Why do you insist on claiming I bought an autoprop? because no one but someone who threw $2,200 on the table for such a tiny improvement in forward speed would write the junk you write. an auto-prop is a variable speed transmission, not a feathering prop. the prop is a *transmission*? OK, that's funny. But given your accuracy in other areas, I guess that kind of claim is to be expected. -- Jim Richardson http://www.eskimo.com/~warlock "$HOME is where your dotfiles are" - Gym Quirk |
that's okay, jimmy. I think of you as a fourth year sophomore failing in his
fifth major on his 12th cup of coffee in the student union cutting yet another three classes. From: Jim Richardson Date: 9/4/2004 3:00 PM Eastern Daylight Time Message-id: On 04 Sep 2004 17:15:55 GMT, Shen44 wrote: Subject: What are the pros and cons of a folding prop? From: Jim Richardson Date: 09/03/2004 19:51 Pacific Standard Time Message-id: On 03 Sep 2004 11:58:59 GMT, JAXAshby wrote: oh, jim, it has been explained in terms even a 10 year kid could understand. get your older sister to explain it to you. Well, I don't have an older sister JAXAshy, so perhaps you can try again. How is the autoprop not feathering? The blades swivel to be inline with the axis of the shaft, and present less drag than in the forward or reverse config. How is that not feathering? Jim, the issue is not whether the autoprop can be called a feathering prop. The issue is, how long can Doodles keep you arguing the point. Yeah, the old adage about mud wrestling with a pig springs to mind... -- Jim Richardson http://www.eskimo.com/~warlock Windows XP... now runs all your favorite viruses. |
If you insist on calling the Autoprop "feathering" then you have to admit its a
pretty poor one, having 5 to 10 times the drag of other feathering props. For example, in the MIT/Practical Sailor test, at about 7 knots the Autoprop had 10 pounds of drag, while the 2 and 3 blade Maxprop feathering props had about 1 and 2 pounds respectively. The folding props were so low they weren't shown. 10 pounds of drag is pretty good, compared to the 25 to 35 pounds for many of the props in the test, but it isn't the same as feathering. The Autoprop has some interesting properties, like very good performance in reverse, if you rev it up. "Jim Richardson" wrote in message ... On 04 Sep 2004 13:08:18 GMT, JAXAshby wrote: Then why did you post a definition of feathering, which fit the autoprop? it does not fit. not even close. and if you had not blown $2,200 on a prop hoping against hope you could make your boat *sail* faster you would know the difference. Did the dealer tell you you could pass Island Packets and Westsail 32 if you bought an auto-prop? I didn't buy one JAXAshby. I simply wanted to know what you meant by calling it a non-feathering prop. Alas, I should have known better than to expect rational discourse from you. -- Jim Richardson http://www.eskimo.com/~warlock 'Windows' really does make a fine swear word, representing all that's taboo and awful - just like '****', '****', etc." -- Mark Hughes, sdm |
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