Setting pitch on an adjustable prop

[GWTW-000]

What is the best thing to use for setting the pitch for an adjustable prop? I have used a Craftsman protractor to get close. Is there a tolerance that is ok ? Is there something else I can use to check the protractor? I know if I am to far off I will have a lot of vibration.

Thanks

 

[SwampMatt]

ccasion5:

 

[kb27_99]

It depends on the prop but the only way i was able to illiminate the vibration on my 78" power shift was to clamp a 2" piece of aluminim to the transom slightly touching one blade and pitch the other one to that point. It took some time to get it perfect but on my 0540 i have zero vibration.



Kevin

 

[futura]

I bought a digital level called the smart tool it will measure to 1/10 of a degree, It does take some time to get both blades to the same degree when you measure at the same position with the prop level but it takes all the guess work out of the setup, Plus you can use it for other things around the house

 

[Anonymous]

Kevin, there's a lot to be said for that method.

Years ago, when you were tracking the rotor blades on a helicopter, you'd rub a black crayon on the tip of one blade, and a red crayon on the tip of the other ...... then run the airplane up and pull in a little pitch to makes the blades flex upward. A crewman would then take a white cotton flag on a pole and VERY CAREFULLY lean it into the ends of the blades until he got a tap..tap. On the flag you'd have a red and a black mark ..... if they were together, you were good to go. If they were more than an inch apart, you'd adjust the link on the lower blade a little and do it over til they matched.

The method you describe is a great double-check after you've used a prop protractor to get the initial setting, in case one of the blades has a little more twist in it than the other.

Ken

 

[nebraskaairboater]

When setting the pitch on the prop I always use a fixed point on the cage, hull, or engine stand and measure the distance from the leading edge to that spot on both blades. If it is the same distance from the same point on the leading edge it should be the same pitch for each blade. It works good for me with no vibration from the prop.

 

[marshmaster pat]

We use a craftsman protractor and then check the distance from a spot on the cage or transom as well. Guess that is a left over from torqueing wooden props and checking to see if they tracked.

 

[swampjet]

I also use the digital torpedo level from SmartTool. Takes all the guesswork out of it. Measures down to the tenths of a degree. Got it online. Best way to go. Just be sure to level the engine first, before pitching the prop.

 

[basketcase0302]

KJC,

Too much money wrapped up in props these days to chance it!

The digital protractor / Smart Tool that Swampjet speaks of is the cat's meow.

Got mine from Penn Tool online, (cheapest in the U.S.A.). Zero it to a plane on the engine block, take your prop manufactors reccomendations on angle and go from there. Waterthunder and Cntry141 will preach that this is one of the areas where you can really see performance gains out the wazoo! (Or lose performance and / or fuel economy as well)!

Basketcase