|
|
There seems to be a bit of confusion here. There are basically 4
different types of props with movable blades. All can improve sailing performance to one degree or another. Folding props: Blades with a fixed pitch are pivoted along the axis of the shaft so that they fold back in the fore and aft direction. Blades may be geared together or independent. In forward they are held open by the forward thrust. Most have some camber so they are close to the efficiency of fixed blades in forward but in reverse they are held open by centrifugal force which means that you have to apply more power to get them to perform in reverse. Folding props are preferred when sail performance take preference over powered performance. Feathering props: Blades are pivoted (more or less) perpendicular to the shaft. They remain extended when idle but align themselves with the flow to present the smallest cross section. The blades are geared to the shaft so that they are held open by the torque. Pitch can be adjusted by modifying the stops. In reverse the torque flips the blade over so that you get the same pitch (and performance) in forward and reverse. However, to achieve the lowest drag the blades usually do not have any camber making them slightly less efficient. Feathering props are preferred where a balance must be struck between sail and powered performance. Variable Pitch Props: Blades are assembled similar to feathering props but are geared to a control shaft concentric to the drive shaft. By adjusting the position of the control shaft relative to the drive shaft from inside the hull the pitch can be varied to meet current conditions. Usually the blades are cambered to optimize forward performance. Variable pitch props are preferred where maximum performance under power in all conditions is desired and cost is not a limiting factor. Auto-Prop: Blades are pivoted similar to feathering props but are independent of each other and can rotate a full 360º. The offset geometry of each blade is designed to find its own most efficient pitch by balancing torque against water pressure. Auto-Props can give close to optimum performance in most conditions in forward or reverse. They are not truly feathering however. With no torque water pressure forces the blades back slightly which results in considerably more drag than normal feathering props. Also they have considerably more mass which puts a lot of strain on the drive train when shifting from forward to reverse and back. If left idle for any length of time they require considerably more maintenance than the others to keep the blades rotating freely. Auto-Props are best where powered performance takes precedence over sailing performance. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
On 30 Aug 2004 03:34:57 GMT, (JAXAshby) wrote:
rhys, hate to tell you this, but an Auto-Prop doesn't feather. From www.autoprop.com "In forward the propellor rotates to the correct pitch automatically. This results in increased propulsion efficiency whcih reduces fuel consumption, and extends cruising range. "While under sail the propellor feathers itself to reduce drag by 85% compared to conventional 3-blade propellors. "The Autoprop also self pitches in reverse to give you the same thrust in reverse as you would get in forward. This greatly improves stopping power, backing down, and overall maneuverability." Note the use of the word "feather" as in "feathers itself", a concept with which I believe you would be familiar, JAX, particularly on those lonely Saturday nights. Still, the clown spent $3,500 Cdn, so you gotta expect him to tell you *something* That "clown" has seen more salt water than Mr. Morton during a flash flood, JAX, including the first private yacht transit of Hudson's Bay since...well, Hudson, so let's just say he doesn't quite have the credibility gap you exhibit with most of your bilious, ill-informed, poorly argued and borderline dyslexic posts. Now, punk, go measure a footwell or something. Sailors are speaking here. Really, could the barrel get any smaller or the fish and the cannon any bigger? R. |
On Mon, 30 Aug 2004 09:39:46 -0400, Glenn Ashmore
wrote: Auto-Prop: Blades are pivoted similar to feathering props but are independent of each other and can rotate a full 360º. The offset geometry of each blade is designed to find its own most efficient pitch by balancing torque against water pressure. Auto-Props can give close to optimum performance in most conditions in forward or reverse. They are not truly feathering however. They are close enough in function to use the term constructively. I don't think Autoprop's self-description of their product as a "feathering prop" constitutes trade fraud in this instance. With no torque water pressure forces the blades back slightly which results in considerably more drag than normal feathering props. Also they have considerably more mass which puts a lot of strain on the drive train when shifting from forward to reverse and back. Agreed. As noted, my friend accepts the wear as adequate pay-off for the motoring performance enhancements he was seeking. I wouldn't put an Autoprop on a J-Boat, for instance, or any racer-cruiser. It's a good compromise if you understand the pros and cons, not a universal panacea for prop drag. If left idle for any length of time they require considerably more maintenance than the others to keep the blades rotating freely. He hauls in a TraveLift once a year (luckily his club possesses one) and inspects and adjusts then as part of his general yearly hull maintenance/cleaning/repainting. He says it's pretty straightforward so far, but he acknowledges that they are complex pieces of machinery for props. Auto-Props are best where powered performance takes precedence over sailing performance. Debatable, if you consider the alternative as being a fixed prop or a folding prop. I think you have to consider hull type, displacement and engine output along with intended use. My friend takes his large steel ketch out alone a great deal, and while he is fine sailing it solo, he appreciates the degree of control his Autoprop gives him in tight situations and in solo docking. Certainly that aspect--the degree of control of a 15 ton boat-- is quite noticeable and is obviously worth it to him in his use of a heavy displacement cruiser. That's why I tried to give both pros and cons, as the Autoprop isn't particularly well-known, being British. Getting one personally would be senseless for my current boat, but seems a good compromise for him and has bought him a few more years out of his 35 HP Volvo, even if he has to rethink transmission isolation and so on. But it's not for everyone. No "marine solution" is, except maybe for those wooden tapered plugs people hang off seacocks. G R. |
On 30 Aug 2004 11:58:56 GMT,
JAXAshby wrote: The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? -- Jim Richardson http://www.eskimo.com/~warlock If Bill Gates had a nickel for every time Windows crashed... Oh wait, he does |
the blades are curved, and rather dramatically so.
The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? -- Jim Richardson http://www.eskimo.com/~warlock If Bill Gates had a nickel for every time Windows crashed... Oh wait, he does |
So,Doodles, what you are saying, is that unless the blades are totally
flat, the term "feathering" can not be used? otn JAXAshby wrote: the blades are curved, and rather dramatically so. The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? |
of course, or very nearly so. That is what the word means. At least to the
professionals. rubber ducky sailors are a different breed, of course. Subject: What are the pros and cons of a folding prop? From: otnmbrd Date: 8/31/2004 10:20 PM Eastern Daylight Time Message-id: . net So,Doodles, what you are saying, is that unless the blades are totally flat, the term "feathering" can not be used? otn JAXAshby wrote: the blades are curved, and rather dramatically so. The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? |
So,Doodles, what you are saying, is that unless the blades are totally
flat, the term "feathering" can not be used? otn let me help improve, over the knee, with your understanding of English words. v. feath·ered, feath·er·ing, feath·ers v. tr. To turn (an oar blade) almost horizontal as it is carried back after each stroke. To alter the pitch of (a propeller) so that the chords of the blades are parallel with the line of flight. |
Well, golly, gee, Doodles, I'm impressed. A simple direct answer to a
simple direct question. Simply stated, for those who live in the real world of boating and propellors, when discussing "Feathering" props with Doodles, keep in mind that if there is any curvature or cupping to the blades, then you will have to determine and use the "Doodles terminology" for this blade and condition, as it does not fully meet the requirements of "Doodles terminology" and is thus unacceptable usage. otn JAXAshby wrote: of course, or very nearly so. That is what the word means. At least to the professionals. rubber ducky sailors are a different breed, of course. Subject: What are the pros and cons of a folding prop? From: otnmbrd Date: 8/31/2004 10:20 PM Eastern Daylight Time Message-id: . net So,Doodles, what you are saying, is that unless the blades are totally flat, the term "feathering" can not be used? otn |
G Isn't it great how easily you can look up these simple definitions,
Doodles? Isn't it a shame that so many people allow these slight variations to the pure and simple definitions of your life to totally corrupt the English language? otn JAXAshby wrote: let me help improve, over the knee, with your understanding of English words. v. feath·ered, feath·er·ing, feath·ers v. tr. To turn (an oar blade) almost horizontal as it is carried back after each stroke. To alter the pitch of (a propeller) so that the chords of the blades are parallel with the line of flight. |
Jere Lull wrote:
In article , (MLapla4120) wrote: I'm going to re-power soon and am also going to get new shaft and prop. It seems that in my boat class (Westsail 32), some people are going to folding props to help speed under sail. I'm for increased speed, but also want reliability. My current bronze propeller is pitted and old. Every time I turn around and look at it, it is full of sea growth. That makes me think I'm getting poor performance. So, I'm for an improvement, but I am unsure of what kind. Any opinions from boaters that have encountered this situation would be appreciated. Thanks, Mark , "Belle" Westsail 32 ANY modern prop will improve your performance under power, forward and reverse. Technology has improved in 30 years. A feathering prop can drastically improve sailing enjoyment if you don't bother to park your prop behind the keel. Your Westsail may not get the improvements we get as we're lighter and cleaner, but we pick up .5 to .8 knots when I remember to stop the prop, which has us sailing more than we used to. Windward performance improved, allowing us to get a bit closer to the wind. We also get more comfortable sailing past hull speed, but the "wetsnail" doesn't have a hullform that allows much of that. We don't have a Westsail of course, but with enough wind, we've gone faster than hull speed a couple of times. What do you mean by getting more comfortable? grandma Rosalie |
On 01 Sep 2004 02:03:35 GMT,
JAXAshby wrote: the blades are curved, and rather dramatically so. So what? feathering a prop doesn't require that there be *no* drag, it's a way to reduce drag, not eliminate it. The autoprop blades rotate to parallel to the axis of the shaft, how is that not feathering? The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? -- Jim Richardson http://www.eskimo.com/~warlock If Bill Gates had a nickel for every time Windows crashed... Oh wait, he does -- Jim Richardson http://www.eskimo.com/~warlock Never be in the company of anyone with whom you would not want to die. -- Fremen Saying |
On 01 Sep 2004 02:28:28 GMT,
JAXAshby wrote: So,Doodles, what you are saying, is that unless the blades are totally flat, the term "feathering" can not be used? otn let me help improve, over the knee, with your understanding of English words. v. feath·ered, feath·er·ing, feath·ers v. tr. To turn (an oar blade) almost horizontal as it is carried back after each stroke. To alter the pitch of (a propeller) so that the chords of the blades are parallel with the line of flight. Well, that fits the autoprop, thanks. -- Jim Richardson http://www.eskimo.com/~warlock It's psychosomatic. You need a lobotomy. I'll get a saw. -- Calvin |
over the knee, English was not your first or second language. please stay out
of discussions on any subject in English. From: otnmbrd Date: 8/31/2004 11:54 PM Eastern Daylight Time Message-id: .net Well, golly, gee, Doodles, I'm impressed. A simple direct answer to a simple direct question. Simply stated, for those who live in the real world of boating and propellors, when discussing "Feathering" props with Doodles, keep in mind that if there is any curvature or cupping to the blades, then you will have to determine and use the "Doodles terminology" for this blade and condition, as it does not fully meet the requirements of "Doodles terminology" and is thus unacceptable usage. otn JAXAshby wrote: of course, or very nearly so. That is what the word means. At least to the professionals. rubber ducky sailors are a different breed, of course. Subject: What are the pros and cons of a folding prop? From: otnmbrd Date: 8/31/2004 10:20 PM Eastern Daylight Time Message-id: . net So,Doodles, what you are saying, is that unless the blades are totally flat, the term "feathering" can not be used? otn |
over the knee. the definition was for your ignorant sake. I knew the term
correctly a long bit ago. From: otnmbrd Date: 9/1/2004 12:11 AM Eastern Daylight Time Message-id: .net G Isn't it great how easily you can look up these simple definitions, Doodles? Isn't it a shame that so many people allow these slight variations to the pure and simple definitions of your life to totally corrupt the English language? otn JAXAshby wrote: let me help improve, over the knee, with your understanding of English words. v. feath·ered, feath·er·ing, feath·ers v. tr. To turn (an oar blade) almost horizontal as it is carried back after each stroke. To alter the pitch of (a propeller) so that the chords of the blades are parallel with the line of flight. |
no it doesn't. take a look at those blades and you will understand, probably.
if not, ask any passing yardworker or dockboy to explain it to you. From: Jim Richardson Date: 9/1/2004 5:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 02:28:28 GMT, JAXAshby wrote: So,Doodles, what you are saying, is that unless the blades are totally flat, the term "feathering" can not be used? otn let me help improve, over the knee, with your understanding of English words. v. feath·ered, feath·er·ing, feath·ers v. tr. To turn (an oar blade) almost horizontal as it is carried back after each stroke. To alter the pitch of (a propeller) so that the chords of the blades are parallel with the line of flight. Well, that fits the autoprop, thanks. -- Jim Richardson http://www.eskimo.com/~warlock It's psychosomatic. You need a lobotomy. I'll get a saw. -- Calvin |
jimmy, look at the blades. if you can't see what they look like and what they
do, look at a prop that feathers and you **should** see the difference. if still not, ask a dockboy to explain it to you. From: Jim Richardson Date: 9/1/2004 5:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 02:03:35 GMT, JAXAshby wrote: the blades are curved, and rather dramatically so. So what? feathering a prop doesn't require that there be *no* drag, it's a way to reduce drag, not eliminate it. The autoprop blades rotate to parallel to the axis of the shaft, how is that not feathering? The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? -- Jim Richardson http://www.eskimo.com/~warlock If Bill Gates had a nickel for every time Windows crashed... Oh wait, he does -- Jim Richardson http://www.eskimo.com/~warlock Never be in the company of anyone with whom you would not want to die. -- Fremen Saying |
JAXAshby wrote: over the knee. the definition was for your ignorant sake. I knew the term correctly a long bit ago. G Knowing the "term" correctly, is one thing. Being able to apply the term to various situations seems to be beyond your abilities. I'd hate to see what you'd do if I sent you to stand by the "forward spring". otn |
|
Yup, Doodles, "various" ..... course now we have to wait and see which
definition ( the simple, complex, or interpretive) you will use to create this argument BG Btw Which line WOULD you go to, to "stand by the fwd spring"? otn JAXAshby wrote: "various", eh? From: otnmbrd Date: 9/1/2004 12:03 PM Eastern Daylight Time Message-id: JAXAshby wrote: over the knee. the definition was for your ignorant sake. I knew the term correctly a long bit ago. G Knowing the "term" correctly, is one thing. Being able to apply the term to various situations seems to be beyond your abilities. I'd hate to see what you'd do if I sent you to stand by the "forward spring". otn |
On 01 Sep 2004 11:41:09 GMT,
JAXAshby wrote: jimmy, look at the blades. if you can't see what they look like and what they do, look at a prop that feathers and you **should** see the difference. if still not, ask a dockboy to explain it to you. I had hoped you would have a point, and debate it, rather than simply sliding into insults. I guess I was hoping for too much. From: Jim Richardson Date: 9/1/2004 5:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 02:03:35 GMT, JAXAshby wrote: the blades are curved, and rather dramatically so. So what? feathering a prop doesn't require that there be *no* drag, it's a way to reduce drag, not eliminate it. The autoprop blades rotate to parallel to the axis of the shaft, how is that not feathering? The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? -- Jim Richardson http://www.eskimo.com/~warlock If Bill Gates had a nickel for every time Windows crashed... Oh wait, he does -- Jim Richardson http://www.eskimo.com/~warlock Never be in the company of anyone with whom you would not want to die. -- Fremen Saying -- Jim Richardson http://www.eskimo.com/~warlock Contrary to popular belief, Unix is user friendly. It just happens to be very selective about who its friends are. -- Kyle Hearn |
On 01 Sep 2004 11:38:55 GMT,
JAXAshby wrote: no it doesn't. take a look at those blades and you will understand, probably. if not, ask any passing yardworker or dockboy to explain it to you. Even the definition of feathering that you yourself brought into this discussion fits the autoprop. From: Jim Richardson Date: 9/1/2004 5:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 02:28:28 GMT, JAXAshby wrote: So,Doodles, what you are saying, is that unless the blades are totally flat, the term "feathering" can not be used? otn let me help improve, over the knee, with your understanding of English words. v. feath·ered, feath·er·ing, feath·ers v. tr. To turn (an oar blade) almost horizontal as it is carried back after each stroke. To alter the pitch of (a propeller) so that the chords of the blades are parallel with the line of flight. Well, that fits the autoprop, thanks. -- Jim Richardson http://www.eskimo.com/~warlock It's psychosomatic. You need a lobotomy. I'll get a saw. -- Calvin -- Jim Richardson http://www.eskimo.com/~warlock Instrument of Darwin |
jim, if you choose to redefine every English word to suit your fancy, there is
no debate possible. green is carrots, rum is gravel, curved prop blades are straight. makes no room for discussion. you bought one and are trying to convince yourself it was a wise "investment". Just like gold will reach $2,000 an ounce six weeks after the election. you are a true-believer, jim, and you pushed the English language around to form it to your convictions. who could debate that? From: Jim Richardson Date: 9/2/2004 4:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 11:41:09 GMT, JAXAshby wrote: jimmy, look at the blades. if you can't see what they look like and what they do, look at a prop that feathers and you **should** see the difference. if still not, ask a dockboy to explain it to you. I had hoped you would have a point, and debate it, rather than simply sliding into insults. I guess I was hoping for too much. From: Jim Richardson Date: 9/1/2004 5:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 02:03:35 GMT, JAXAshby wrote: the blades are curved, and rather dramatically so. So what? feathering a prop doesn't require that there be *no* drag, it's a way to reduce drag, not eliminate it. The autoprop blades rotate to parallel to the axis of the shaft, how is that not feathering? The blades rotate until they are inline with the shaft axis, how is this not feathering? take a look at the blades. they rotate and thus *reduce* drag, but they certainly don't "feather". I have, the blades rotate to line up with the axis of the shaft, how is that *not* feathering? -- Jim Richardson http://www.eskimo.com/~warlock If Bill Gates had a nickel for every time Windows crashed... Oh wait, he does -- Jim Richardson http://www.eskimo.com/~warlock Never be in the company of anyone with whom you would not want to die. -- Fremen Saying -- Jim Richardson http://www.eskimo.com/~warlock Contrary to popular belief, Unix is user friendly. It just happens to be very selective about who its friends are. -- Kyle Hearn |
and green is lollipops to a true-believer, jim.
look up the term "cognitive dissidense" (pardon the terbil spelink, but you ain't gonna look the psychological underpinnings to your behavior anyway) From: Jim Richardson Date: 9/2/2004 4:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 11:38:55 GMT, JAXAshby wrote: no it doesn't. take a look at those blades and you will understand, probably. if not, ask any passing yardworker or dockboy to explain it to you. Even the definition of feathering that you yourself brought into this discussion fits the autoprop. From: Jim Richardson Date: 9/1/2004 5:30 AM Eastern Daylight Time Message-id: On 01 Sep 2004 02:28:28 GMT, JAXAshby wrote: So,Doodles, what you are saying, is that unless the blades are totally flat, the term "feathering" can not be used? otn let me help improve, over the knee, with your understanding of English words. v. feath·ered, feath·er·ing, feath·ers v. tr. To turn (an oar blade) almost horizontal as it is carried back after each stroke. To alter the pitch of (a propeller) so that the chords of the blades are parallel with the line of flight. Well, that fits the autoprop, thanks. -- Jim Richardson http://www.eskimo.com/~warlock It's psychosomatic. You need a lobotomy. I'll get a saw. -- Calvin -- Jim Richardson http://www.eskimo.com/~warlock Instrument of Darwin |
On 02 Sep 2004 12:14:22 GMT,
JAXAshby wrote: jim, if you choose to redefine every English word to suit your fancy, there is no debate possible. green is carrots, rum is gravel, curved prop blades are straight. makes no room for discussion. The definition you yourself provided for feathering, fits the autoprop. The blades rotate to inline with the fluid flow. How is that not feathering? you bought one and are trying to convince yourself it was a wise "investment". Just like gold will reach $2,000 an ounce six weeks after the election. you are a true-believer, jim, and you pushed the English language around to form it to your convictions. who could debate that? Well, given that your assumption that I bought one, is in error, the rest of your "logic" proceding from that error, is equally flawed. -- Jim Richardson http://www.eskimo.com/~warlock Linux: There is no conspiracy... yet -- Matthew Adair |
On 02 Sep 2004 12:17:42 GMT,
JAXAshby wrote: and green is lollipops to a true-believer, jim. look up the term "cognitive dissidense" (pardon the terbil spelink, but you ain't gonna look the psychological underpinnings to your behavior anyway) There's a trend here, When JAXAshby loses a debate on the technical issues, he starts flinging insults. noted. -- Jim Richardson http://www.eskimo.com/~warlock Instruction ends in the schoolroom -- but education ends only with life. -- Publilius Syrus. |
Subject: What are the pros and cons of a folding prop?
From: Jim Richardson I had hoped you would have a point, and debate it, rather than simply sliding into insults. I guess I was hoping for too much. He had neither a point to make nor the ability or interest to debate it. As per usual, Doodles was just trying to "stir the pot". He probably has less experience with feathering props than I do, and I have none .... only used to "zero pitch" type props. Shen |
no, the chord does. which word don't you understand?
From: Jim Richardson Date: 9/2/2004 1:30 PM Eastern Daylight Time Message-id: On 02 Sep 2004 12:14:22 GMT, JAXAshby wrote: jim, if you choose to redefine every English word to suit your fancy, there is no debate possible. green is carrots, rum is gravel, curved prop blades are straight. makes no room for discussion. The definition you yourself provided for feathering, fits the autoprop. The blades rotate to inline with the fluid flow. How is that not feathering? you bought one and are trying to convince yourself it was a wise "investment". Just like gold will reach $2,000 an ounce six weeks after the election. you are a true-believer, jim, and you pushed the English language around to form it to your convictions. who could debate that? Well, given that your assumption that I bought one, is in error, the rest of your "logic" proceding from that error, is equally flawed. -- Jim Richardson http://www.eskimo.com/~warlock Linux: There is no conspiracy... yet -- Matthew Adair |
jim, it is you who lost the debate two days ago when you told one and all you
didn't even understand that terms, let alone the principles involved. even when I explained the terms to you, you still couldn't keep up. From: Jim Richardson Date: 9/2/2004 2:00 PM Eastern Daylight Time Message-id: On 02 Sep 2004 12:17:42 GMT, JAXAshby wrote: and green is lollipops to a true-believer, jim. look up the term "cognitive dissidense" (pardon the terbil spelink, but you ain't gonna look the psychological underpinnings to your behavior anyway) There's a trend here, When JAXAshby loses a debate on the technical issues, he starts flinging insults. noted. -- Jim Richardson http://www.eskimo.com/~warlock Instruction ends in the schoolroom -- but education ends only with life. -- Publilius Syrus. |
On 03 Sep 2004 04:01:46 GMT,
JAXAshby wrote: no, the chord does. which word don't you understand? The "chord does" What JAXAshby ? -- Jim Richardson http://www.eskimo.com/~warlock "Human beings can always be counted on to assert with vigor their God-given right to be stupid." -- Dean Koontz |
On 03 Sep 2004 04:04:08 GMT,
JAXAshby wrote: jim, it is you who lost the debate two days ago when you told one and all you didn't even understand that terms, let alone the principles involved. even when I explained the terms to you, you still couldn't keep up. You haven't explained anything yet. But I am still hopeful. So how is the autoprop not a feathering propellor JAXAshby? -- Jim Richardson http://www.eskimo.com/~warlock Remember - if all you have is an axe, every problem looks like hours of fun. Frossie |
jim, redefine any and all words you can to "prove" (to yourself and any
doubters out there) that your spending $2,200 for a prop to make your boat go 1/10th knot faster was one hell of a smart "investment". the word "feathering" can not be used in the context of a corkscrew prop such as an auto-prop. except by "investers" mentioned above. an auto-prop is an auto-prop. the blades twist a little under high power/low speed, twist a little differently under low power/low speed, and twist something differently under no power/any speed. the drag on the prop is still very high indeed (as a percentage) compared to a genuine feathering prop. auto-props are sold (by the manufacturer at least, if not always by the dealer) as a variable speed transmission. 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. From: Jim Richardson Date: 9/3/2004 4:00 AM Eastern Daylight Time Message-id: On 03 Sep 2004 04:01:46 GMT, JAXAshby wrote: no, the chord does. which word don't you understand? The "chord does" What JAXAshby ? -- Jim Richardson http://www.eskimo.com/~warlock "Human beings can always be counted on to assert with vigor their God-given right to be stupid." -- Dean Koontz |
oh, jim, it has been explained in terms even a 10 year kid could understand.
get your older sister to explain it to you. From: Jim Richardson Date: 9/3/2004 4:00 AM Eastern Daylight Time Message-id: On 03 Sep 2004 04:04:08 GMT, JAXAshby wrote: jim, it is you who lost the debate two days ago when you told one and all you didn't even understand that terms, let alone the principles involved. even when I explained the terms to you, you still couldn't keep up. You haven't explained anything yet. But I am still hopeful. So how is the autoprop not a feathering propellor JAXAshby? -- Jim Richardson http://www.eskimo.com/~warlock Remember - if all you have is an axe, every problem looks like hours of fun. Frossie |
On 03 Sep 2004 11:57:24 GMT,
JAXAshby wrote: jim, redefine any and all words you can to "prove" (to yourself and any doubters out there) that your spending $2,200 for a prop to make your boat go 1/10th knot faster was one hell of a smart "investment". Why do you insist on claiming I bought an autoprop? the word "feathering" can not be used in the context of a corkscrew prop such as an auto-prop. except by "investers" mentioned above. Then why did you post a definition of feathering, which fit the autoprop? an auto-prop is an auto-prop. the blades twist a little under high power/low speed, twist a little differently under low power/low speed, and twist something differently under no power/any speed. the drag on the prop is still very high indeed (as a percentage) compared to a genuine feathering prop. auto-props are sold (by the manufacturer at least, if not always by the dealer) as a variable speed transmission. Fact remains, the blades on the autoprop swivel to be inline with the shaft, and present less drag than in the forward or reverse direction, how is that not feathering? 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. -- Jim Richardson http://www.eskimo.com/~warlock Does Emacs have the Buddha nature? Why not? It has bloody well everything else |
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 Richardson http://www.eskimo.com/~warlock "We have to go forth and crush every world view that doesn't believe in tolerance and free speech," - David Brin |
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. |
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? |
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? |
| All times are GMT +1. The time now is 04:43 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com