Does anyone else have a campbell sailor prop on their boat? If you do have one have you had any trouble backing your boat up? Does your boat have a severe tendency to back -to-port? Mine does and I am trying to figure out why. Does anybody have this problem with other brands of propeller? I thought that it was the way I was steering the boat but the guys at the yard where I store my boat had the same results as I didwhen they tried to back up. I have tried to contact campbell but they haven't answered as of today. Anybody have any ideas? I want add that I am well aware of prop walk and this problem goes well beyond what would be concidered normal.
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John Coleman
Backing an H37C
Mike I don't know which prop is on my cutter, I believe it is the original two blade, but it has more than a tendancy to go to port in reverse. It is due to porp-walk. All single screw boats do this to some degree. The 37C seems to do it very well. Bay Ship and Yacht Company are reported to have a modification to a regular two bladed prop the reduces prop-walk and consequently the tendancy to go to port. See link. Let us all know if you find a solution. John S/V Slainte 1983 H37C
Mike I don't know which prop is on my cutter, I believe it is the original two blade, but it has more than a tendancy to go to port in reverse. It is due to porp-walk. All single screw boats do this to some degree. The 37C seems to do it very well. Bay Ship and Yacht Company are reported to have a modification to a regular two bladed prop the reduces prop-walk and consequently the tendancy to go to port. See link. Let us all know if you find a solution. John S/V Slainte 1983 H37C
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Pat McCartin
Prop walk...
What is realy going on is called P factor. The same dillema occures in aviation, a single engine airplane will tend to pull left on the ground. The reason is because the prop takes a "stronger bite" on the downward stroke than the upward. This causes unballanced thrust and the walk or yaw. There is realy no way to correct the problem as is is exacerbated by the increased inclination of the prop shaft angle vs. horizontal, Talk to a good prop shop they may have a "special" bend or cup for the prop to help. I've heard the 3 blade props will also help, I have a 2 blade so I can't comment. Pat McCartin
What is realy going on is called P factor. The same dillema occures in aviation, a single engine airplane will tend to pull left on the ground. The reason is because the prop takes a "stronger bite" on the downward stroke than the upward. This causes unballanced thrust and the walk or yaw. There is realy no way to correct the problem as is is exacerbated by the increased inclination of the prop shaft angle vs. horizontal, Talk to a good prop shop they may have a "special" bend or cup for the prop to help. I've heard the 3 blade props will also help, I have a 2 blade so I can't comment. Pat McCartin
Did not know that they had that graphic.
Pat: It is funny but Bob Kilan they inventor of the NO-SLIP-TIP says that a three blade prop is actually worse than a two blade prop when it comes to prop walk. It has something to do with the water pushing against the hull. There are mix responses about the ability of these props to perform as advertised. Most of the comments are positive. I would speak with Bob Kilan at Bay Props and explain about any specifics. He will explain what one should expect with the modification. One think to keep in mind that you should have about 15% of the props diameter as clearance between the prop tip and the hull. If you put a new prop on a boat and incure more prop walk, the distance between the tip and the hull is probably too small. Putting a non-slip-tip will obviously help because it reduces this distance by about 1/2 inch.
Pat: It is funny but Bob Kilan they inventor of the NO-SLIP-TIP says that a three blade prop is actually worse than a two blade prop when it comes to prop walk. It has something to do with the water pushing against the hull. There are mix responses about the ability of these props to perform as advertised. Most of the comments are positive. I would speak with Bob Kilan at Bay Props and explain about any specifics. He will explain what one should expect with the modification. One think to keep in mind that you should have about 15% of the props diameter as clearance between the prop tip and the hull. If you put a new prop on a boat and incure more prop walk, the distance between the tip and the hull is probably too small. Putting a non-slip-tip will obviously help because it reduces this distance by about 1/2 inch.
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David Foster
Bay Prop worked on my h27
The tips can be worked onto an existing prop. It cost about $150 to have our two blade original prop modified. The results were: 5 to 10% more speed in the same conditions. (We cruise at 4.5 versus 4.0 knots at easy RPM's.) Reduction in noise an vibration. Slight reduction in prop walk - but it's still definite. The theory is a reduction in tip vortexes that carry energy away from the stream pushed back by the prop (in forward.) For the same reason, modern jets have winglets on the end of their wings. The improvements were slight but definite. The 10% improvement in cruising speed is actually a big deal! David Lady Lillie
The tips can be worked onto an existing prop. It cost about $150 to have our two blade original prop modified. The results were: 5 to 10% more speed in the same conditions. (We cruise at 4.5 versus 4.0 knots at easy RPM's.) Reduction in noise an vibration. Slight reduction in prop walk - but it's still definite. The theory is a reduction in tip vortexes that carry energy away from the stream pushed back by the prop (in forward.) For the same reason, modern jets have winglets on the end of their wings. The improvements were slight but definite. The 10% improvement in cruising speed is actually a big deal! David Lady Lillie
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Ed Allen
learn to use it to your advantage.
for me the prop walk is a major help. the prop walk problem is a great advantage when you want to back to port. you are not going to eliminate it. on my 37c i find that it is worse if i go in reverse and put on a lot of power. so i slow the boat almost to a stop before i use reverse. no big deal in most situations. i use the prop walk to my advantage in close situations. the boat will turn a lot quicker to port in reverse so backing in a slip is easier when it is to port. once the boat in moving aft it is greatly reduced because the rudder starts to work. not as well as it does in forward because the water flow over the rudder is much slower in reverse. so dont over steer in reverse till the boat gets moving then use the rudder to guide you where you want to go.
for me the prop walk is a major help. the prop walk problem is a great advantage when you want to back to port. you are not going to eliminate it. on my 37c i find that it is worse if i go in reverse and put on a lot of power. so i slow the boat almost to a stop before i use reverse. no big deal in most situations. i use the prop walk to my advantage in close situations. the boat will turn a lot quicker to port in reverse so backing in a slip is easier when it is to port. once the boat in moving aft it is greatly reduced because the rudder starts to work. not as well as it does in forward because the water flow over the rudder is much slower in reverse. so dont over steer in reverse till the boat gets moving then use the rudder to guide you where you want to go.
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richard shelby
prop walk good
Ditto Ed's comment. I couldn't get out my corner slip without prop-walk. My H37C has a big 3-blade. The only exit is off the port quarter.I leave the bow tied on, walk in reverse to port about 30 degrees, then throw off the bow line. After a few feet of reverse headway I then have steerage. Also you can back off a starboardside pier without scraping the topsides by backing to port easier than you can turn to port going forward.
Ditto Ed's comment. I couldn't get out my corner slip without prop-walk. My H37C has a big 3-blade. The only exit is off the port quarter.I leave the bow tied on, walk in reverse to port about 30 degrees, then throw off the bow line. After a few feet of reverse headway I then have steerage. Also you can back off a starboardside pier without scraping the topsides by backing to port easier than you can turn to port going forward.
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scott wilson
Mike, different prop same result
I have a two blade geared folding Gori prop. I have severe prop walk to port in reverse. My slip configuration reguires a backing turn to starboard to leave the dock. First I put on about 1/3 throttle for about 3 seconds and the stern goes 30 degrees in the "wrong" direction with the rudder not quite full over to starboard. When half way out of the slip I go to neutral and the boat starts to recover its stearageway. When the stern is a few feet from the boats across the fairway, I'm still pretty much straigh out from my slip, maybe the stern moved a few decrees past recovering from the intial turn to port. But when I shift to forward and put the rudder hard over to port and "goose" the thottle a couple of seconds, there is severe prop walk to starboard and I make the 90 degree turn in forward that I wasn't able to do in reverse. So my experience tells me to get the boat moving in reverse, and then "drift" in neutral without prop walk to get the stern around to starboard.
I have a two blade geared folding Gori prop. I have severe prop walk to port in reverse. My slip configuration reguires a backing turn to starboard to leave the dock. First I put on about 1/3 throttle for about 3 seconds and the stern goes 30 degrees in the "wrong" direction with the rudder not quite full over to starboard. When half way out of the slip I go to neutral and the boat starts to recover its stearageway. When the stern is a few feet from the boats across the fairway, I'm still pretty much straigh out from my slip, maybe the stern moved a few decrees past recovering from the intial turn to port. But when I shift to forward and put the rudder hard over to port and "goose" the thottle a couple of seconds, there is severe prop walk to starboard and I make the 90 degree turn in forward that I wasn't able to do in reverse. So my experience tells me to get the boat moving in reverse, and then "drift" in neutral without prop walk to get the stern around to starboard.
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Ed Allen
Did some asking arround
my friend has an Erickson 29. he had a three blade on it and went to a campbell 3 blade. this is a radically different prop. they sized it for him and i came right on. works great. better speed at mid range throttle and much faster backing. he still has about the same prop walk. they are quit unusual but im thinking of going to one on my 37c. also they claim much less drag than a conventional prop.
my friend has an Erickson 29. he had a three blade on it and went to a campbell 3 blade. this is a radically different prop. they sized it for him and i came right on. works great. better speed at mid range throttle and much faster backing. he still has about the same prop walk. they are quit unusual but im thinking of going to one on my 37c. also they claim much less drag than a conventional prop.
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Fred G
Another prop walk technique
As you have probably figured out from all these responses, prop walk occurs in all of our boats regardless of which propeller you have. I originally had factory 2 blade, but have since switched to a 3 blade in search of more thrust to help me fight local tides. The technique I use to over come propwalk is to put the boat at an angle that will compensate for the prop walk. I know that my 3 blade will rotate my 81' H 30 more than the old 2 blade did, so I simply point the bow to port about 50 degrees off my intended reverse course before I start, then put the boat in reverse and throttle up hard. The boat stops and the stern rotates hard to port (about 50 degrees), and eventually gains speed in reverse. Once I have speed I regain steerage, and I can throttle back and steer normally the rest of the way.
As you have probably figured out from all these responses, prop walk occurs in all of our boats regardless of which propeller you have. I originally had factory 2 blade, but have since switched to a 3 blade in search of more thrust to help me fight local tides. The technique I use to over come propwalk is to put the boat at an angle that will compensate for the prop walk. I know that my 3 blade will rotate my 81' H 30 more than the old 2 blade did, so I simply point the bow to port about 50 degrees off my intended reverse course before I start, then put the boat in reverse and throttle up hard. The boat stops and the stern rotates hard to port (about 50 degrees), and eventually gains speed in reverse. Once I have speed I regain steerage, and I can throttle back and steer normally the rest of the way.
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mike alge
I talked to a rep from West By North this afternoon and he said I should take some measurements and call him back. It seems there is a certain distance between the bottom of the boat and the blade tips that must be maintained. This clearance or rather the lack of it is the main cause of excessive prop walk. I will keep you informed of what I find and what I have done to correct it. He informed me that excessive prop walk is not normal and should be corrected.
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chet p
campbell prop
i put one of the 3 blade props on my 37c when i repowered 2 years ago and i don't have anything to compare it to but it seems to work great. prop walk is ALWAYS a problem, but you learn to live with it. next year when i have the boat hauled i will most likely have it repitched as i can't quiet get it up to max rpm's of 3000 but at 2600-2700 i get full 7+ knots and no smoke. i am spinning a 15x13- 3 blade on a 3 cyl westerbeke 31 Hp engine....
i put one of the 3 blade props on my 37c when i repowered 2 years ago and i don't have anything to compare it to but it seems to work great. prop walk is ALWAYS a problem, but you learn to live with it. next year when i have the boat hauled i will most likely have it repitched as i can't quiet get it up to max rpm's of 3000 but at 2600-2700 i get full 7+ knots and no smoke. i am spinning a 15x13- 3 blade on a 3 cyl westerbeke 31 Hp engine....
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