For Sale: Campbell Sailor Propeller

[malbert73]

Almost new-
13 inch diameter, 13 inch pitch 3 blade bronze

I used it for a season, and it was great, especially compared to the 2 blade prop that came with it. I have put back the original michigan propeller MP3 which hinders sailing performance comparatively, but gives slightly better punch upwind. Have carried the Campbell prop as a spare for 1 year but am unlikely to use it again and want to recoup some of my costs- as I can swap underwater for 2 blade for sailing performance, or the 3 blade for powering.
Would like $150, but will consider offers! Pix available on request

[malbert73]

Whoops
forgot some key info:

7/8 inch bore, RH prop

[ring8266]

If your 13" campbell sailor prop is still for sale, I would like to buy it. Would like to spend $125.00 for it, because I will need to send it back to Campbell and have it changed to a 1" shaft and a 9" pitch for my 30' Hunter. Hope your willing? Ray in Valdosta, Ga.

[Blue Stocking]

Am thinking of changing the 3 blade 17 x 13 Michigan on my boat to a Campbell sailor, after reading advantagious Campbell data and feedback. You indicate the Campbell didn't seem to have the forward punch of the Michigan. Hmm!! interesting--any further opinion would be appreciated. Thanks.

[roverhi]

I would like the prop for $150 if it's still available. Let me know how to send the money.

[malbert73]

Thanks for the replies. I sold to highest bidder.

For those interested- the Campbell prop is a really nice prop, but blade area always wins out despite feedback to the contrary. So no matter what they do to the blades, you'll never get quite the performance from small bladed props as from large bladed props like the MP3. If you want a fraction more sailing performance at the cost of a fraction of powering performance, then the Campbell is a great choice...

[Maine Sail]

Originally Posted by malbert73

Thanks for the replies. I sold to highest bidder.

For those interested- the Campbell prop is a really nice prop, but blade area always wins out despite feedback to the contrary. So no matter what they do to the blades, you'll never get quite the performance from small bladed props as from large bladed props like the MP3. If you want a fraction more sailing performance at the cost of a fraction of powering performance, then the Campbell is a great choice...

This statement is 100% out of phase with my experience doing the exact same conversion, Michigan to CS. My guess is that your CS was not properly pitched or cupped for your application? Mine was shipped back once to get it spot on. The first round it was over pitched and could not attain max rated engine RPM. Second round she is within 30 RPM of max rated as measured with a digital photo tachometer.

I removed a 16X12 Michigan MP and replaced it with a 16X9 Campbell Sailor. There is NO comparison. The CS has more punch through chop, less prop walk, less vibration and more speed under sail. The only thing it does not do niticibly better is stopping the boat but that performance measure is at least equal to the Michigan MP, just not what I would call technically "better".

Prop efficiency does not totally have to come from blade surface area. Dave Gerr talks about this in his prop book. My properly sized CS has proven that to me as it performs every aspect better, other than putting on the brakes, than the Michigan Wheel did, although putting on the brakes is at the least equal to the Michigan.


Here's my take on the CS based on my experience:

Sizing A CS:

Sadly prop sizing is not such an exact science, despite all the science in Gerr's book and in the Michigan Wheel prop calculator software. 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 and the vast majority of owners had no idea they were over or under propped.

The CS prop is extremely efficient. Norm spec'd mine at 16" diameter by 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. Not good, and I consulted at length with the engineers at Westerbeke over this 300 RPM discrepancy. Over propping your engine is not a great 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. It is important to accurately know your motors RPM and often the alternator driven tachs can be off by some degree. I used a digital photo tach for RPM confirmation

If you've been reading carefully the Campbell Sailor is a full 3 increments of pitch smaller than the Michigan Wheel, for the same diameter, and has far less surface area for less drag through the water. Efficient, is a good way to describe this prop. 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:

My CS 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. 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. The CS does this with ease and I notice better head wind and chop performance than I did with the Michigan Wheel. We also motor against some very strong tidal currents and the CS has performed flawlessly and tackled these currents with ease and smoothness.
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.

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


Here's a photo of the sheer reduction in surface are which helps result in the large reductions in drag between the MW and the CS (13 pounds vs. 39 pounds):



Before you sell your prop I would call Norm and explain what you are seeing. I am sure he will help you out. It would be good to know your engines max rated RPM and what the actual RPM is at WOT with a clean bottom and prop with no current. This information can help Norm get your prop sized nearly perfectly. I find it very hard to believe that the CS performed poorly compared to a Michigan Wheel. My experience with a 36 footer of about 17k displacement is 180 degrees out of phase with yours?

[malbert73]

I appreciate your feedback on this--

Very helpful- but I already went through the repitching process once. The problem I have with my boat is that I am limited to a 13-14 inch prop by my aperture, while the ideal prop size for my engine is a 16-17 inch prop. I think there is only so much you can do with short skinny blades compared to short fat blades. I had the prop pitched so I could get within 50 RPM of max with both props, but I still get 0.3-0.4 knots more boatspeed with the MP3. Go figure....
Truth is, I finally got the right prop from Norm, but I must have caught him on an off week because first he shipped the wrong bore prop, and then he shipped a lower pitch than I had wanted....