We also have a problem with the numbers that're written on the props. There actually is no accepted standard throughout our model prop industry. Of course, the diameter number is going to be reliable for comparison, but the pitch number isn't even close.

Some years back, there were a couple of pitch gauges on the market. Back then a good percentage of the modelers in the hobby did a lot of things themselves. And reworking props, although not done by a lot of guys, was done by enough that the sale of pitch gauges was worth mfg'ing and selling them. Those gauges tell an interesting story. Turns out that a 10x6 from one mfg didn't have the same pitch (as measured by the gauge) as another mfg's 10x6 had. That actually isn't proof that one or the other mfg was wrong. It did prove however what a lot of knowledgeable modelers knew. There is more than one airfoil and AOA that'll produce a given performance.

Unfortunately, knowing that there are different ways to get six inches worth of performance out of a 10" prop doesn't stand as proof that one mfg or the other IS GETTING six inches of pitch results. It actually only shows that they're trying different ways. But sometimes it helped explain why one 10x6 didn't fly like a 6" pitch prop. Because we very often found that the mfg's printed pitch number really was not giving what it should, nor what other props of that pitch gave.

After all those words........ what's my point?
The guys who were seriously interested in pitch discovered that you could not bet on the advertised number. Truth is, to us it wasn't a biggie. We had learned to test and go with what worked and if the numbers were good, good for them.

Now, was there any value to all this "setup"? Hope so..............

contd.................