SailNet Community banner
  • SailNet is a forum community dedicated to Sailing enthusiasts. Come join the discussion about sailing, modifications, classifieds, troubleshooting, repairs, reviews, maintenance, and more!

3-blade fixed prop recommendations?

18K views 28 replies 15 participants last post by  rikhall 
#1 ·
I'm looking for a 3-blade fixed prop; probably want a sailboat prop but I also need something that will deliver good thrust. The sailboat props seem to have reduced blade width to minimize drag. At times we need to motor against current here on SF Bay and my current prop is just too small for my needs. The prop is a 12" x 14" on a 40hp diesel engine. I did some checking on the prop sizing tables and it looks like it is correct for the 3500 max RPM the engine will deliver; but at normal cruising RPM's of 2500 I don't get up to hull speed (7.5 kts) and I get lots of vibration above 2600 because I suspect the prop is a bit over-pitched and under-bladed which results in cavitation. My ratio is 1.5:1 (I think) which gives shaft speeds about 1/3 lower than engine RPM.

So I was wondering what others have found good results with? I am looking at the Campbell Sailer and the Michigan Wheel Sailer props; are there any others I should be looking at? How do these two compare?
 
#5 ·
On our last boat we went from a 2 blade 18x16 Martec folder to a 3 blade Campbell Sailor prop - and were surprised to have Norm (a great guy, btw) at West By North recommend a 17x11... but the prop worked great for us, much smoother under power, good "brakes" but of course a bit slower under sail.

When the time comes to reprop, if we can't spring for a folder/featherer we'll do the Campbell again... but currently leaning toward the Kiwi prop - also available from West by North.
 
#6 ·
Faster-

Did you go from running at lower RPM with the 18x16 to higher RPM with the Campbell Sailer? What boat did you have and what was the engine HP and reduction? That's a huge change in prop pitch in addition to a smaller diameter.

On the Martec props; I have heard about the pins wearing the bronze at the hinges; how long does a Martec prop typically last before the prop needs repair or replacement? Seems that galvanic corrosion and wear due to thrust on those pin holes is inevitable due to the design.
 
#7 ·
It was a Choate 40, about 17,000 lbs actual, with a 50HP Pathfinder and Hurth V-150 (don't recall the exact reduction but you can look it up I'm sure) What we noticed most about the change was the smoothness, the cruising RPM differed only by a couple of hundred rpm (higher) It's been a few years now but I believe we cruised at 7 knots at around 2400rpm.

On our Martec (non-geared folder) the cheeks into which the blades fit to be pinned had "splayed", opening up a bit allowing extra clearance for some vibration. While we coveted a MAX prop, just couldn't justify the cost for the type of sailing we did then. The Campbell was a good (inexpensive ~$750CDN 10 years ago) compromise.
 
#9 · (Edited)
Re: Campbell Sailor

Here's a review I posted on another forum earlier this fall:

After much research and consternation I decided on a new prop this past winter.

Mechanical vs. Fixed:

As much as I would have liked a feathering prop, Max-Prop was my choice, I decided against it after speaking at length with my local prop shop and a few friends at boat yards. With the tides in Maine we get lots of floating debris, floating line and lobster pots. As was stated to me by more than one prop shop, and more than one boat yard employee, the mechanical props are just not as reliable when you hit something. This happens in Maine. This is not to say they are not durable but when I was staring at a four year old mechanical prop overhaul, on the bench at my local shop, for "$900.00-$1000.00", it made my decision that much easier.

The minimal drag of a feathering prop would be awesome but I don't race my own boat so 3-6 seconds per mile lost out to durability, simplicity and reliability. Folders were not even considered this time around and because I have already owned them in the past it was easy to rule them out this time.

Two blades vs. three:

For me this one is easy. Over the years I have had numerous two blade props and have never found one I liked. When I want to use my motor I want a real motor not the feel of an electric trolling motor.;) With the tidal currents in Maine and the lack of summer winds we often see, having a smooth well balanced three blade prop is a must for us.

I am not one who is afraid to fire up the Japanese genny when the wind dips below 5 knots, especially with an antsy toddler who's ready for some island exploring etc... We also like to venture up some of our many rivers which can have massive currents. Two blade props have never given me a feeling of total confidence, with a small aux motor, in battling head on with these currents.

Which Fixed Prop?:

After lots of research I decided on a Campbell Sailor Prop ("CS" from here forth). I had read many, many, many prop reviews & discussions using the search tool on about 20+ sailing forums, from SBO to SCCA to SailNet, and every one in-between. One thing I noticed was that I had not read much if any negative comments about the CS. So the Campbell Sailor three blade it was.

Ordering:

After consulting with Norm at West By North, the makers of the Campbell Sailor. I ordered a 16"X10X1" RH prop. The prop took about three to four weeks for delivery which was fine due to my off season planning.

Sizing:

Contrary to popular beliefs and misconceptions prop sizing is NOT an exact science. In order to hit max RPM and size the prop to do that without going over or under by much is not easy and often takes two or more attempts to get it spot on. I can remember working with my old friend Brian, a marine surveyor, who always checked the prop sizing against max rated RPM. We found that close to half the boats had the wrong size prop.

The CS prop is EXTREMELY efficient. Norm spec'd mine at 16" diameter X a 10 pitch. I was skeptical at first because my three blade Michigan Wheel was a 16" X 12 pitch which is a lot more aggressive. I could not understand how, with loosing so much surface area, I could also reduce pitch? Norm used the Michigan Wheel prop size calculator, which he tweaks for the CS prop design, and decided on the 16X10. Unfortunately when I got the 16X10 it was still over propped and I was under max rated RPM by about 300 RPM. Not good.. Over propping your engine is never a good idea so I wanted to fix this as soon as possible.

Once I discovered the 16X10 was still to aggressive, despite the blade surface area being MUCH smaller than the Michigan Wheel, I called Norm. Norm decided to drop the pitch to a 9 and remove some of the cupping on the trailing edge of the CS props blade.

The customer service Norm provides is stellar! He actually sent me a brand new replacement prop ahead of time so I could literally change out my prop, with the boat still in the slings, and then send the used 16X10 prop back. The 16X9 prop worked flawlessly and I am now within 30 RPM of max rated with a clean bottom and prop.

If you've been paying attention the Campbell Sailor is a full 3 increments of pitch smaller than the Michigan Wheel prop and has far less surface area for less drag through the water. Efficient does not even begin to describe this props unique design. Pitch is basically the theoretical travel a prop makes in one revolution. For example a 10 pitch will theoretically travel 10" in one full revolution provided there is no "slip", but there is almost always slip..

Vibration / Smoothness:

This prop has proven to be the smoothest prop I have ever used or owned on a sailboat. The drive train exhibits no vibration throughout the entire RPM range even at WOT. My Michigan Wheel was tuned and balanced less than one year ago and still could not compete with the smoothness of the CS even on a brand new shaft.

Prop Walk:


Despite the aggressive design of the CS blades the prop displays considerably less prop walk than did the Michigan Wheel. I can not say it has none, but it is about 70% better than the fixed three blade Michigan was.

Drag:

As some of you may know I conducted my own little prop drag study. The results were rather eye opening. The CS prop has about 13 pounds real of drag at about 4.2-4.4 knots while the three blade Michigan Wheel had about 39 pounds of drag at only 4-4.2 knots. For those of you doing the math that is roughly a 200% increase of drag for the Michigan 16X12 than for the CS 16X10. Yes, this is still more drag than a Max-Prop but nowhere near the drag of the Michigan Wheel..

Speed:

I have always run my boat to put the stern wave right at point where my the hull sides and transom meet but without the water climbing up the transom. This puts me at about 6.6-6.8 knots. I used to be at 2400 RPM to do this with the 16X12 Michigan Wheel and am now consistently at about 2250 to do the exact same thing with the CS 16X9. Both props would hit a WOT max rated throttle of 3000 RPM within +/- 30 RPM.

Fuel Use:

I could not decipher any real measurable difference in fuel consumption perhaps because we also have engine driven refrigeration which tends wreck the mathematics of measuring fuel consumption for moving the vessel through the water.

Conclusion:


If you are looking for a rugged, reliable, smooth and efficient fixed three blade prop with less drag than the typical Michigan Wheels, that come standard on most boats, then the Campbell Sailor certainly fits the bill.

While slightly more expensive than a Michigan Wheel it is certainly considerably less than any of the feathering or folders. I think i paid about $540.00 delivered but I'll need to find my credit card statement to be sure..

I waited until I had nearly a full season of use to post this so it could be more accurate and less impulsive. I find if I write something shortly after I buy it I can be admittedly little more biased, in a pro fashion, towards it, then if I wait and use it more. After nearly a full season of use I find I like it even more now than when I initially bought it, perhaps due to the sizing mishap.

Here's cross sectional comparison of the props unique design comparing the CS to the MW:



Here's a photo of the sheer reduction in surface are which helps result in the 200% reduction in drag between the MW and the CS (13 pounds vs. 39 pounds):
 
#10 ·
Having purchased a Campbell sailer myself I second everything that has been said and will buy another when I need to. But I was not told that I would be charged for repitching and ultimately paid several hundred more to get it right.
Now if they had used my requested pitch (based on Catalina factory recomend) rather than their own ideas initially I would expect it to pay for changes, but they (CS) told me they new best from experience. The final pitch was exactly what I had asked for originally (Catalina did know best)
So I would get it in writing who is paying for repitching and the associated costs. Two repitch's meant pulling the boat three times. Ouch. thanks Norm
TJ
 
#11 ·
Great writeup "poster formerly known as Halekai"! I think that is just the information I was looking for to convince me that if I go with the fixed blade CS prop; it is the right one for the job. Still can't decide between a fixed blade and a possibly new larger Martec for ~200 more; since my prop is offset from centerline of the boat I need all the drag reduction I can get. But the CS prop looks so nice for the reasons you stated about getting the proper pitch and it being an efficient blade design.

I'm afraid that the Martec might increase my shaft vibration problem; as I don't know for sure what the cause of it is. It could be cavitation and 2-blade prop vibration; or it could be alignment or engine bed vibration (fiberglass pan). I suspect that a standard Martec could worsen it; are the Elliptec props any lower in vibration than the older Martec prop design?
 
#12 ·
TJ-

What was the recommended pitch/diameter VS the pitch/diameter combo that West by North set your prop to?

I'm thinking that I want my new prop to be slightly oversized and then just run the engine at lower RPM. 3000 RPM for a Diesel engine is very fast; and most Perkins 4-108 owners tend to run their engines in the 2200-2400 RPM range at hull speed.
 
#13 ·
Maine Sail, mind telling me what make and model your japanese genny is ?
I too have a CS prop. At 3RH 14Dx6P I can do 3300-3500rpm on my 2GM20F. I later repitch it to 14Dx7P and max I got is 2800rpm (slightly higher if prop, shaft and hull is clean). Wonder if I should go back to 6P.
 
#14 ·
How Well does the Campbell Sailor Back Down?

Maine Sail,

Your recommendation has started me thinking about the prop on Tranquility Base. How well does the Campbell Sailor on your boat back down? That's the single gripe I have with my current prop. I get maybe 10% of the acceleration in reverse that I get in forward when I increase engine speed, probably less. It makes backing into the slip on a windy day interesting.

For what it is worth, Tranquility Base has a 2 blade, fixed 13 X 10 right hand prop powered by a Yanmar 2GMF. I don't know who manufactured it, but the blade cross section is close to uniform thickness with a little curve to it. The blade width to length ratio looks very similar to the CS blades in your picture. I don't see much vibration, even at WOT. I can get to max RPM at WOT, and I ran around for 1/2 hour at WOT w/o overheating when I tested the engine last Spring. This prop drives the boat at hull speed around 2800-2900 RPM (depending on how clean the bottom is) so the pitch is good. But it won't back down worth beans. I think I could accelerate the boat faster by poling than this setup does in reverse!
 
#15 ·
Re pitching Campbell Sailor

Tractor John's post back in Nov. 2009 refers to pitching issues with Sailor prop. I'm hoping you can give me some info. regarding your setup before/after to compare. Also what was Catalina's recommendation?
I have a Catalina 36 with a M35B Universal. Michigan Wheel recommends 15" x 9" 3 blade..... Norm says" 14" x 8" 3 blade Sailor.

Thanks,
Mike (MikeSB)
 
#16 ·
FWIW we went from an 18x12 Martec folder to a Campbell 17x11 without issues, smoother operation and good (much better) backing as well. The adjustment Norm is suggesting seems standard when switching to Campbell Sailor props.
 
#17 ·
I sail a Marshall Sanderling (Marshall 18) catboat, equipped with a Yanmar 1GM Diesel which originally drove a generic 2-blade Michigan "Sailor" 12 x 10 prop via a 2.62:1 gear. Though the prop was properly matched (it allowed the engine to just reach its intermittent max rpm of 3600 at wide-open throttle), it produced vibration and noise out of proportion to its power. Norm at West By North Enterprises convinced me that there was no sailing advantage to the 2-blade (simple test: I stopped the prop from windmilling with my hand, and there was no change in drag when I had the prop blades vertical), and talked me into trying the Campbell Sailer 3-blade. Right off the bat I noticed far less vibration at all speeds and GALA VI was much easier to back and maneuver (though I still drop the centerboard a few inches). I also won the Catboat Class race at the 2011 Provincetown Schooner Regatta! Only problem was that the engine now topped out at just shy of 3200 rpm. After corresponding with Norm, I took the prop to a local propeller shop over the winter and had a bit of cupping removed from the trailing edge; voila-the engine now maxes out at 3500 (close enough for rhythm & blues) and I cruise the boat at about 5 kts. at 2600-2800 rpm depending on conditions. This leaves plenty of headroom for punching into strong headwinds/seas if necessary, etc. I couldn't be happier with it.
 
#18 · (Edited)
Regarding pitching issues, it seems from my own experience and what I'm seeing here that some tweaking becomes necessary when going to a CS prop; my original 2-blade was a 12" x 10" and was replaced by a 12" x 6" CS-exactly half the pitch! (I forgot to mention the dia./pitch in my previous post). As it turned out, I still had to have some adjustments made at New England Propeller in Plymouth, as the engine would not go above about 3150 rpm. They (and Norm) recommended against any further reduction in pitch, but simply removed some of the cupping. This solved the problem. While I never had any real problems backing or stopping with the old 2-blade, I notice that she's a lot more surefooted now; the only problem I have with propwalk is when I have a decent breeze pushing against my starboard side, and even then, it's more manageable. It's worth noting here that my Yanmar's Hurth/Kanzaki gear-like that on most small Yanmars-has a higher ratio astern than ahead; ahead it's 2.62:1, going astern it's 3.04:1. Even with the lower shaft speed going astern, this prop pulls its weight without overrevving the engine.
 
#19 ·
I too have a 3 blade Campbel Sailor prop, and feel that I should report that I'm considering changing back to a larger bladed prop. I can vouch for all the advantages previously mentioned, and Norm got the size and pitch right the first time.

However, a downside I experience is that even the tiniest bit of seaweed snags on this and kills the thrust. My speed will drop from 5 knots to 2 knots when I pick up some seaweed, and it happens all the time! I've wondered if the reason I have so much trouble with seaweed is that my prop is tucked in behind the deadwood in the rudder aperture of my Alberg 30, so is handicapped from the start.

It doesn't take much seaweed either. It's rare that I can go an hour motoring without having to stop and use reverse to spin some of the seaweed off.

Previous to the CS prop, I had a large bladed Michigan Wheel style prop and it rarely had any trouble with seaweed.

-PK
 
#20 ·
I'm doing a gasoline to diesel repower and am working on the same issue. I think what matters in performance is having the correct pitch/diameter/blade area combination. If you want to get into this the ultimate reference for us amatures is Gerr's "Propeller Handbook". Besides all the basic info it gives the info so you can make your own calculations. I went to Michigan Wheel and they entered thier data into thier computer and were failly close in pitch however thier blade area was too low for the cavitation curve calculations so it was good to have done them. You may find the book at the library.
 
#21 ·
It's been a long time since I sailed in Maine-unfortunately-so I can't remember what kind of seaweed you encounter up there. Here on the outer Cape, we have quite a bit of a type of seaweed which looks like big clumps of sawgrass floating just below the surface; only once have I had a problem with it. Not long after I first installed the new prop, I was running from the mooring to the town dock and suddenly all hell broke loose; all kinds of vibration and noise, and the boat slowed down to a crawl. Of course the first thing I thought of was the prop was coming off, the shaft was bent, etc. etc. I went to neutral and looked over the transom, and saw a huge bunch of this weed trailing from the screw. I reversed a couple of times and it came off. Knock on wood, hasn't happened again. I can't say that this wheel is more susceptible to fouling than what I had before-the only thing that ever fouled my 2-blade was a length of 5/8" nylon line, leading to my first working experience with a scuba tank! I should note that my prop is also in an aperture, cut into the deadwood ahead of my barn door-style rudder.
 
#22 ·
It's been a long time since I sailed in Maine-unfortunately-so I can't remember what kind of seaweed you encounter up there. Here on the outer Cape, we have quite a bit of a type of seaweed which looks like big clumps of sawgrass floating just below the surface; only once have I had a problem with it. Not long after I first installed the new prop, I was running from the mooring to the town dock and suddenly all hell broke loose; all kinds of vibration and noise, and the boat slowed down to a crawl. Of course the first thing I thought of was the prop was coming off, the shaft was bent, etc. etc.
This is exactly what I experience, except it happens all the time! I often end up getting in the dinghy at the end of the day to pull seaweed from the prop.

I wonder why my setup is such a seaweed magnet?



Could it be the gap between the and of the bearing and the start of the prop?? Perhaps I should try a shaft zinc in front of the prop to take up the space. ?
 
#24 ·
I see you have an external bearing support, thus the prop is much farther away from the deadwood; on my boat it's very close to the deadwood as the cutless bearing is pressed into the deadwood itself. In fact, there's no room for a zinc ahead of my prop; I use a "doughnut" zinc clamped to the propeller nut. You might try a doughnut zinc ahead of the prop and see if it helps.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top