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#1
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Angle of prop shaft - theoretical question
In way of stressing something otn is saying.
The major component of thrust for any angle of prop rotation is aft/back. The components for up, down, to the right, to the left, are small. Keep in mind that when we are saying up, down, right or left, we are not saying straight up,down,left or right, but simply modifying the straight back component ....slightly. When going ahead, for most boats, the hull will never really feel or be impacted by that "up" component, for the simple reason that it's up angle will not reach the hull, prior to it clearing the stern. When going astern, the same thing applies. The water is not be so much directed "UP" or "Into" the hull, as it is being directed along the hull and quickly clear of the hull, which allows for the same decreased efficiency of the 090 - 270 arc of the rotation in reverse (RH prop). Steve, I think otn's response basically covered what I would have generally said in my response to your last post to me, so I'll let his stand. Shen |
#2
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Angle of prop shaft - theoretical question
shen, the "down" component is indeed quite noticeable. In fact, it is the
reason outboard runababouts have the steering wheel on the right side of the boat. In way of stressing something otn is saying. The major component of thrust for any angle of prop rotation is aft/back. The components for up, down, to the right, to the left, are small. Keep in mind that when we are saying up, down, right or left, we are not saying straight up,down,left or right, but simply modifying the straight back component ....slightly. When going ahead, for most boats, the hull will never really feel or be impacted by that "up" component, for the simple reason that it's up angle will not reach the hull, prior to it clearing the stern. When going astern, the same thing applies. The water is not be so much directed "UP" or "Into" the hull, as it is being directed along the hull and quickly clear of the hull, which allows for the same decreased efficiency of the 090 - 270 arc of the rotation in reverse (RH prop). Steve, I think otn's response basically covered what I would have generally said in my response to your last post to me, so I'll let his stand. Shen |
#3
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Angle of prop shaft - theoretical question
Subject: Angle of prop shaft - theoretical question
From: (JAXAshby) shen, the "down" component is indeed quite noticeable. In fact, it is the reason outboard runababouts have the steering wheel on the right side of the boat. "THE" reason? No. If it was THE reason and the boat needed that offset weight to counter the "down" component, imagine what might happen when you put the engine in reverse. Is it a possible reason, among a number of reasons - yes - the particular application will dictate it's degree of importance, if any. Shen |
#5
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Angle of prop shaft - theoretical question
On Sun, 13 Jun 2004 17:37:04 GMT, something compelled
(Steven Shelikoff), to say: On 13 Jun 2004 16:18:03 GMT, (Shen44) wrote: Subject: Angle of prop shaft - theoretical question From: (JAXAshby) shen, the "down" component is indeed quite noticeable. In fact, it is the reason outboard runababouts have the steering wheel on the right side of the boat. "THE" reason? No. If it was THE reason and the boat needed that offset weight to counter the "down" component, imagine what might happen when you put the engine in reverse. Is it a possible reason, among a number of reasons - yes - the particular application will dictate it's degree of importance, if any. Do they put the helm on the other side if the prop turns the other way? They put the helm on the right hand side because the traffic approaching you from that direction has the right of way, and it's important that you be able to keep an eye on it. Jeeze. |
#6
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Angle of prop shaft - theoretical question
They put the helm on the right hand side because the traffic
approaching you from that direction has the right of way, and it's important that you be able to keep an eye on it. nah. outboards have had rh turning props since loooooooooooooooooooooooooooong before the Rules of the Road (originally an east coast yacht club's racing rules). Ole Evinrude's engines (built in Milwaukee and sold to and for Midwestern fishermen operating on Midwestern lakes a three or four day train ride from the east coast) turned clockwise (from the top) because most men are right handed (and this made it easier to hand start the engine turning cw) and a cw turning engine could have a cheaper, longer-lived thrust bearing in the lower unit if the prop turned right, thus lifting the right side of the boat from the reaction to the torque of the prop. Therefore, the boat operator sat on the right side of the boat. Still true to this day for outboards. |
#7
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Angle of prop shaft - theoretical question
On Sun, 13 Jun 2004 14:34:38 -0700, "Steve Daniels, Seek of Spam"
wrote: On Sun, 13 Jun 2004 17:37:04 GMT, something compelled (Steven Shelikoff), to say: On 13 Jun 2004 16:18:03 GMT, (Shen44) wrote: Subject: Angle of prop shaft - theoretical question From: (JAXAshby) shen, the "down" component is indeed quite noticeable. In fact, it is the reason outboard runababouts have the steering wheel on the right side of the boat. "THE" reason? No. If it was THE reason and the boat needed that offset weight to counter the "down" component, imagine what might happen when you put the engine in reverse. Is it a possible reason, among a number of reasons - yes - the particular application will dictate it's degree of importance, if any. Do they put the helm on the other side if the prop turns the other way? They put the helm on the right hand side because the traffic approaching you from that direction has the right of way, and it's important that you be able to keep an eye on it. Jeeze. I was hoping it was obvious that it was a fecetious question. Guess not. Steve |
#8
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Angle of prop shaft - theoretical question
Subject: Angle of prop shaft - theoretical question
From: (Steven Shelikoff) Date: 06/13/2004 10:37 Pacific Standard Time Message-id: On 13 Jun 2004 16:18:03 GMT, (Shen44) wrote: Subject: Angle of prop shaft - theoretical question From: (JAXAshby) shen, the "down" component is indeed quite noticeable. In fact, it is the reason outboard runababouts have the steering wheel on the right side of the boat. "THE" reason? No. If it was THE reason and the boat needed that offset weight to counter the "down" component, imagine what might happen when you put the engine in reverse. Is it a possible reason, among a number of reasons - yes - the particular application will dictate it's degree of importance, if any. Do they put the helm on the other side if the prop turns the other way? Steve Depends on the quality of construction. A well constructed boat will have the steering station mounted on a pivot, held in place by brass wingnuts, so's you can shift it port or stbd, depending on prop rotation. Shen .... the occassional troller |
#9
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Angle of prop shaft - theoretical question
Steven Shelikoff wrote:
On 13 Jun 2004 16:18:03 GMT, (Shen44) wrote: Subject: Angle of prop shaft - theoretical question From: (JAXAshby) shen, the "down" component is indeed quite noticeable. In fact, it is the reason outboard runababouts have the steering wheel on the right side of the boat. "THE" reason? No. If it was THE reason and the boat needed that offset weight to counter the "down" component, imagine what might happen when you put the engine in reverse. Is it a possible reason, among a number of reasons - yes - the particular application will dictate it's degree of importance, if any. Do they put the helm on the other side if the prop turns the other way? Steve YES, our 1954 Feathercraft with the 30/33hp Scott, and later 40hp McCulloch, had the steering on the left from the factory. When we switched to a 50hp Johnson in 1975, the steering & all controls were moved to the right. Our 5hp Scott was a LH prop job too... Rob |
#10
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Angle of prop shaft - theoretical question
Subject: Angle of prop shaft - theoretical question
From: "Steve Daniels, Seek of Spam" Date: 06/13/2004 14:34 Pacific Standard Time Message-id: On Sun, 13 Jun 2004 17:37:04 GMT, something compelled (Steven Shelikoff), to say: On 13 Jun 2004 16:18:03 GMT, (Shen44) wrote: Subject: Angle of prop shaft - theoretical question From: (JAXAshby) shen, the "down" component is indeed quite noticeable. In fact, it is the reason outboard runababouts have the steering wheel on the right side of the boat. "THE" reason? No. If it was THE reason and the boat needed that offset weight to counter the "down" component, imagine what might happen when you put the engine in reverse. Is it a possible reason, among a number of reasons - yes - the particular application will dictate it's degree of importance, if any. Do they put the helm on the other side if the prop turns the other way? They put the helm on the right hand side because the traffic approaching you from that direction has the right of way, and it's important that you be able to keep an eye on it. Jeeze. ....... or they put it on the left, so's you can watch the traffic which is s'posed to be gettin outa your way, depending on which you feel is more important ..... course, for them what don't know the "Rules" and could care less .... they puts it in the middle. |
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