On my 1982 Oday 39 ( universal M50 engine, 44 hp), the original 18" x 13 " 2 blade prop is quite noisy ( high pitch ). Would a 3 blade prop lower the noise level? How about a MaxProp, 2 blade vs 3 blade, and how about their noise level? Thanks
You probably find that a certain rpm's, the prop "squeels". This is because to blades have too sharp of an edge. Take it to a prop shop and tell then to flatten the ends. Roc
Dear Mr. Bernard Maille: Thank you for your questions. It is very common for a two-blade unit to create more noise then the three blade. This noise can result from the lack of surface area on the two blade and its 30% reduction of efficiency when we compare it to the three. We would also want to check the obvious things like propeller tip clearance and is the two blade fixed properly balanced. We would also try to confirm that the propellers diameter and pitch are not overloading the engine minimizing the motors capability. Because the propeller shaft and propeller operate at a 7+ degree angle, as the propeller passes a 12:00 position it begins to build in force until it reaches the 6:00 position. As the blade then begins to rise back towards the 12:00 it then reduces in force. Thus if we follow two blades we will see that as one enters it’s maximum force range the other is just entering it’s weakest point. When we increase the propellers blades to three we then reduce the potential difference between the blades creating a quieter environment. So in most cases when we replace a two blade with a three, we will reduce the noise levels of the running gear. These facts will hold true for Max-Prop whether a two or three blade. This will also hold true for any fixed or low drag propeller. Thanks for your questions. Sincerely Kevin L. Woody
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
