Why three-blade versus two-blade propellers?
We can supply a two-blade propeller but very seldom recommend them for sailboats. The old adage of hiding the two blades behind the deadwood/keel is the main reason not to go with two blades today. Whether you have a full keel or fin keel, both blades go through the disturbed water off the keel at the same time. You end up with 100% power while in clear water then 100% slip as it passes through the deadwood or disturbed water, on/off/on/off/on/off. This slip decreases efficiency, lack of control and causes harmonics (vibrations) that transfer through the hull. A three-blade propeller only has one blade traversing through the disturbed water at a time. More power, less vibration and more control.
What about increased drag with a three-blade?
Depending on the type of propeller you have, you might have a lot or with a Campbell Sailer you could have that reduced to what could be comparable to dragging a hand in the water or less. Generally the wide two blade propellers, that we replace, have more drag than the three-blade Campbell Sailer propellers.
Why do builders supply two-blade with new boats?
Not all builders do but a lot of production boat builders meet what is a lot of the customer’s expectations and that leads us back to the “old adage”. Unfortunately, a lot of them put on the wide, large blade area, powerboat propellers in both two and three blade configurations. This is done mainly because of costs but it is like towing a bucket when sailing.
Why do your propellers cost more than other fixed blade sailboat propellers?
The Campbell Sailer propeller is built specifically for your installation. They are not machine cast and finished on a production line. Each propeller is cast and bored to your shaft size, pitched, balanced, stamped with size/date, finished and spray coated to reduce growth on prop surfaces and discolouration from handling and shipping. All casting work is done by hand with attention paid to details. It usually costs a little more to have a better product.
Can a Campbell Sailer be re-pitched?
Yes, the manganese bronze in Campbell Sailer props is very ductile, giving the prop an extreme ability for major alterations, if required. You could have a propeller for a gasoline engine and use the same propeller for a new diesel that you may install. Providing the rotation is the same, we could change a CS3RH14x6x1 to a CS3RH14x14x1 to accommodate the new or rebuilt engine.
Do I have to send the propeller back to you for re-pitching or fine-tuning?
You can but we have established an Authorized Campbell Sailer service center in New York so far and are looking at other high propeller populated areas for more. These service centers can service and sell the product. By using this center you can save on the costs of sending the propeller back across the border.
Where are your service centers?
Precision Propeller Repair
78 Bridge Street
Newburgh, NY, 12550,
Ph: (845) 562-3880
Fax: (845) 569-1558
1027 East 26th Street
Haileah, FL, 33013, USA
Can any propeller shop fine tune or re-pitch the Campbell Sailer propeller?
Any propeller shop that uses gauges to pitch a propeller instead of pitch blocks can re-pitch (fine-tune) a Campbell Sailer propeller. This is something that you can ask the local prop shop. We would prefer to discuss it with them but it would not be absolutely necessary unless the modification included cutting down the diameter. In that case, we would like to discuss the method of maintaining the reverse air foil and tip profile. This would be necessary to maintain the performance of the propeller to your expectations.
Why are your propeller size recommendations lower than other manufacturers and propeller shops?
The Campbell Sailer is more efficient than the standard propellers that are available and it loads an engine up more, usually by about two inches of pitch and/or diameter.
What makes a Campbell Sailer more efficient than regular propellers?
Referring to the cross section of the blade in our web page under “The Right Stuff” tab. You can see the reverse air foil in the forward side of the blade. This helps to draw the propeller forward with very little of the blade fighting the water that it is trying to push the boat through. On a standard propeller 50% or more of the blade is fighting the water. There is very little pitch in the first third of the blade near the hub, concentrating the pitch on the outer two thirds. The propeller blade design sheds the air bubbles at the hub. By almost eliminating the bubbles from running across the surface of the blade, we have a propeller that is pushing more solid water, instead of compressing air bubbles. Improved efficiency is the result. The outer two thirds of the propeller have progressive pitch, Jim Campbell called this his “ring of power”.
Why does the Campbell Sailer work so well in reverse?
The reverse air foil on the forward side of the blade, when in reverse acts as a cup. This reduces cavitation in reverse providing more thrust. This is so, even when the reduction ratio in reverse is higher than in forward in most transmissions. The reason that you may have to rev higher in reverse to stop or slow the boat.
Why does the Campbell Sailer have less drag than other fixed blade propellers?
The slim blade design is the primary reason.
How can you get so much forward thrust with so little blade area?
We make up for the low blade area by cupping the trailing edge of the propeller. This adds extra thrust in forward and also eliminates some cavitation. There is very little pitch in the first third of the blade near the hub, concentrating the pitch on the outer two thirds. The propeller blade design sheds the air bubbles at the hub. By almost eliminating the bubbles from running across the surface of the blade, we have a propeller that is pushing more solid water, instead of compressing air bubbles. Improved efficiency is the result. The outer two thirds of the propeller have progressive pitch, Jim Campbell called this his “ring of power”. The average pitch is taken and marked on the propeller hub.
How long does it take to get a propeller?
We can make a propeller in 3 – 7 days after receipt of order and payment. It takes UPS-std 4 – 7 days to deliver. If you request and pay for quicker delivery such as UPS-Expedited or Express which is 3 days and 2 days guaranteed delivery, then we expedite the production and delivery to three days or less. This would apply to all sizes under 20” of which we stock many castings. For sizes over 20”, if we don’t have the castings available then it takes 3 – 4 weeks to make. We stock castings based on demand and as the demand goes up so does the inventory of casting.