How to measure prop pitch?

Joined
Feb 10, 2004
Messages
6
I have a propeller of unknown pitch. Is there a method of measuring, to a reasonable degree of accuracy, the pitch without having sophisticated instrumentation? I understand the definition of pitch, just have not been able to devise a methodology to establish it. Thanks.
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: How to measure prop pitch?

If you can find someone with a few used or rebuilt props on hand, you can usually eyeball them and come pretty close. I don't know of any simple formula.
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: How to measure prop pitch?

Should be stamped on the prop hub. If not, a prop shop will tell you in a heartbeat for nothing.<br /><br />More Reading:<br /><br /> web page
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: How to measure prop pitch?

I have a simple method of estimating, FF, but every time I offer it I get shouted at because it isn't spot-on.<br /><br />Use the above advice. :D
 

Forktail

Ensign
Joined
Feb 11, 2002
Messages
977
Re: How to measure prop pitch?

I posted this a while back in another thread. Hope it helps...<br /><br />If you're truly interested in measuring the propeller's pitch correctly yourself, here is one crude suggestion.<br /><br />Place your prop face-up on a flat surface (aft faces of the blades up). Draw a reference line along the face of one of the prop blades, along its center from hub to tip. Then measure out from the center any convenient distance (preferably 70-75% blade length) and make a tick mark. This will be your radius measurement. Draw a transverse line across the blade face, at right angles to the radius line, through the radius tick mark. Take a straight-edge and lay it on this transverse line so that its bottom edge runs off the prop blade and just touches the flat surface or table top. Place a carpenter's square against the straightedge anywhere along the high side. Note the vertical height from the table top at that point. This will be your height measurement. Measure the base, the distance along the table top from the point of the straightedge, on the table, to the bottom corner of the square. This will be your base measurement. Then use the pitch formula.... Pitch = 2 pi x Radius x Height / Base.<br /><br />This method is hard to measure with, and gets less accurate with more complex blade designs, but it will get you close. After doing it a while you will find ways to refine your measuring techniques.<br /><br />Or, here are some other suggestions....<br /><br /> http://homepages.apci.net/~michalak/15mar03.htm#Propellor Pitch <br /><br /> http://www.soinc.org/wristuff/pgagerh.pdf <br /><br /> http://rcboat.com/febtech.htm <br /><br /> http://marlongofast.tripod.com/models/pitchGtxt.htm <br /><br /><br /><br />Also if you're from South FL, you may want to check out prop shops in the following places. They have a Prop Scan tool, and they can probably tell you exactly what pitch your prop is for free.<br /><br />Ft. Lauderdale, Bradenton, St. Petersburg, Port Canaveral, Jacksonville.
 
Joined
Feb 10, 2004
Messages
6
Re: How to measure prop pitch?

Thanks for all your replies. I will try a couple of the approximate methods, and then take it to one of our prop shops in south Florida for a more precise answer.
 
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