I have been using the Hughey Propeller Measuring Gauge for 15 years and have never thought much about it. I have recently started getting more serious about the finer points of propeller measurement and the ability to duplicate my efforts with propellers. I can analyze the pitch and the efficiency of propellers VERY WELL with this gauge. I have developed a system which I will describe. I made up a simple spreadsheet in Quattro Pro and Excel to keep the records and do some of the mathematical calculations. I will describe how I measure a prop with this gauge and if you find it informative and a necessary tool, GREAT! First, you can get the Hughey Propeller Measuring Gauge by calling Ed Hughey at 317-299-3303 during regular business hours.

If you are interested in prop measurement and documentation, you should download the FREE spreadsheet before you analyze this tech article. If you use Quattro Pro - Click Here to Download. If you use Excel - Click Here to Download. If you have an older version of either and it won't read this you will want to download the older versions. For Quattro Pro Older Versions - Click Here, for Excel Older Versions - Click Here. After you download, AND unzip, move the file PROPDOC.XLS or PROPDOC.WB2 to your directory for Quattro Pro or Excel.

Here We Go!

You will want to describe the prop, the date, and your estimated engine RPM. Take calipers and measure the total diameter of the prop and input this in decimal measurement in the column "Measured Prop Diameter Inches". This will output the conversion into Millimeters. The next column is the MOST IMPORTANT setup measurement outputted. This represents the distance you will want to set with your calipers BETWEEN THE TWO POSTS OF THE MEASURING GAUGE. This figure adjusts for the centerline of each of the posts and calculates 70% outward from the center of the propeller shaft hole. Why do I move out 70%? I believe that this is the area on the propeller that does MOST of the work. ALL my measurements are taken at this 70% point. You will want to use 2 of the pitch gauges supplied with the Hughey gauge. I use the first step .126" and the .250" gauge. You will input the degrees you read in these columns where it says Hughey Degrees .1275" and Hughey Degrees .250". How do you measure the prop? The prop is placed on the shaft upside down and the sharp pointer is positioned using the calipers BETWEEN the large shaft and the small shaft as outputted in the .70 from hub Measurement. Then adjust the prop so the small pointer just hits the Far Trailing Edge of the prop (it almost drops off the back). Set the pointer at 0 degrees and rotate the pointer and set the .1275" or .250" gauge under the center of the stem. Read the degrees of rotation and input this amount in the column Hughey Degrees. The pitch will automatically be outputted. You will need to input the MPH that the prop actually runs on your boat and the amount of slippage is automatically outputted in the column Percent Prop % Slippage. This is helpful to find the best and most efficient prop for your application. There are a few props shown as information. I might tell you that the 1450 is the one I used at the IMPBA nats this year and the S-30 is the one I used to run 18.8 sec on the oval. The others are good props from some FAST friends of mine. After you get used to the Hughey Propeller Measuring Gauge, I know it will become one of your most valuable tools! Let me know if you have any interesting props which don't seem to fit any mold, and we can try to figure out why it is better than anything else. Until Next Month……….

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