That is correct. I spoke with Rupert Wasey of Hercules Propellers some years ago and can confirm.He had two programs, the newer one was consulting only. The other was for sale and I’m pretty sure Hercules was one of the purchasers. I think both talked about it on HBA. He use to post some screen shots sometimes.
There's no magic in Carlson's program; he just never told us what book he used to derive his method, but he did not hide the fact that it was a method he found in a book. So a survey of the literature might help instead of trying to reverse engineer it. (P.S. It's RAF-6, not RAF-4.)TFF, Good question, I have gotten to the Chord lengths yet it was hard enough to get the Basics of Pitch and Angle (B) at every 15% station.
Remember this is just his basic program, I was going to apply Paul Lipps approach of Elliptical Lift distribution for the Chord Lengths and also look to Jack Norris's approach to compare - but all that is a long slow process. It took me a week of spare time to get this far - like others I had been putting this research off for some considerable time. I had two copies on different computers and when one was corrupted I figured it was about time to understand the basic processes.
JC doesn't use modern airfoils, he used a combination of Clark Y and RAF 4, he did offer up that information. From research, others consider that using Laminar Flow Airfoils to be a waste of time, probably considering bugs and damage to the leading edge.
It is a very interesting exercise and an education in itself for those interested in the how and why. My experience is that most people just want something off the shelf, or professionally made. The local Prop maker (now retired), made a beautiful wooden prop, with an indestructible leading edge and brilliantly copied proven propeller designs, but had absolutely no idea of how to calculate and design one.
Personally I think everyone should know the basics, so I will offer up as much as I lean, when it's available - to those who are interested.
George, are you working from the same reference sources as he was? Can you be more specific about where this discrepancy is showing up?JC's calculations the Angle (B) at 15% is 48.42 - My answer was 48.41832095, one would initially think a simple rounding-up of the number. I did.
However at 100%, my angle (B) is 25.01533069 where JC's is 23.83 - more than 1° difference, down.