campbell prop

[soul searcher]

was just curious if any one has any expieriance with a Campbell sailer propeller? The good the bad and it's definatley ugly.

I found the info at west by north.


Thanks
Matt.

[Rick]

Matt, I'm very interested in reading any respondes to your query as well. My last cruising boat had (still has) a prop made by the Japanese. I have tried to get info as to where to get a similar one because it was the best compromise for a fixed (as opposed to feathering) three-blade prop that I have experienced.

The Campbell sailer prop looks similar yet I cannot tell without a side view. That Japanese prop has thinner longer blades like the Campbell and, when viewed from the side, you could see that the blades are swept back. so, in addition to the usual pitch and diamater one needs to be concerned about the cord length in proportion to the total "wing" length as a ratio along with the amount of sweep back (similar to dihedral on a wing?) angle.

The overall result was a much lower drag as compared to the same pitch and diameter of the usual power boat prop, and great power upwind and against the seas and a good bite going in reverse. I cannot truly say that the prop walk was a lot less because it is on a heavy boat with a very good rudder and underbody which facilitated turning in both directions very well anyway and I would need to put the usual powerboat prop on to make a comparison.

I did play with letting the prop rotate under sail versus stopping the shaft. For sure the drag was less at high hull speeds when the prop was not allowed to rotate, just like most predictions made by the engineers. It was more difficult to tell under two or three knots yet the engineering predictions say that the drag is still higher all the way until the stiction causes the shaft to stop.

[Alan Wheeler]

Rick, I do know that there was a Japenese prop made by Nakamichi. Now don't go with that spelling as being correct. I believe it is how you pronounce it, but I think the spelling may be a little different. There is a sound company called Nakamichi and I was pretty sure the prop company has a slightly different spelling. But anyways, it could help you get started with a search. When I get home tonight, I will try a search around for some info. I came across it just recently somewhere. I will try and find it again.

[colemj]

Hi Matt,

I had one on my previous boat. I once posted on another board about it:
http://cruising.sailboatowners.com/f...35056,campbell

Mark

[soul searcher]

Thanks Mark,
How were they cost wise. I put in a request but havent herd back from them yet.

Rick,
If you go to http://westbynorth.com and click on the Cambell and then on faqs. It has alot of info basicaly its a progressive pitch propeller. wich oddley enough was going to be my next question. and its cupped so they get more pull/push with less actual pitch. sounds good I spoke with the guys at PyI the other day and even with a OEM price break the max is just to much if I could free up a half knot under sail with a fixed prop and still be able to change it out underwater that would be great. I would pay a little more for that. and I want a back up prop anyway. curious how much more they are than a new michigan.

Thanks again
Matt

[colemj]

Hi Matt,

I paid $360 + shipping in 2001. At the time, this was only ~$30 more than the cheapest price I could get on an equivalent Michigan Wheel prop. Norm at West by North was great to work with and spent a lot of time doing an analysis of my needs and answering questions. He was one of the best people in the marine industry I have ever worked with. One caution is that he will probably recommend a pitch that seems too low. He will probably be right. I didn't heed his advice and increased the pitch (the MW prop I was replacing was 14x12 and he recommended 14x7 - I chose 14x9). I ended up sending it back to be repitched lower after it wouldn't allow my engine to reach 2/3 max rev. They look small and thin, and seem like they would just spin froth in the water, but they are very efficient and bite well. Especially in reverse. Removed almost all prop walk also. I was very happy with it.

Mark

[soul searcher]

Thanks Mark, Ill get in touch with them.


Matt

[Raven RawsonPH]

Originally Posted by Alan Wheeler

Rick, I do know that there was a Japenese prop made by Nakamichi. Now don't go with that spelling as being correct. I believe it is how you pronounce it, but I think the spelling may be a little different.

Alan, I searched and found two Japanese propeller makers: Mikado and Nakashima. Maybe it was Nakashima you were thinking of. In case you remembered more, or anyone has more experience with Campbell Sailer props, I'm hoping to re-energize this discussion before plunking down another 400 bucks for a prop that might turn out to be the wrong size.
Anyone?
Where I've come from is that my Rawson 30 had a 12x6 prop when I bought it. It looked waay puny, and the Perkins had to be revved up to 2300 to get close to its hull speed of 6.2 knots. So, I ordered a Michigan Machine Pitch (much wider blades than the DynaFlo style that was on it, but recommended by Michigan for sailboats). The size is 14x9. I had a 12x9 on my last Rawson, so thought this was going to be much better. Well, after rebuilding the Velvet Drive 1:1, I did a test, and found I'm at hull speed at 1700, but the engine won't go over 2000 to the 3200 the chart says I should do, so I guess I've overpropped. I could have the prop man take some pitch out, but I'm thinking this Campbell Sailer might be a quantum leap better, and maybe I won't have such extreme prop walk.
Any reactions/experiences you might share out there?
Thanks,
...Tom