Interesting. I think I see now. So, starting at anything much more than 5+ degrees would be a big, slow drag. It would turn slow like a water pumper until a bigger wind finally came along to turn it backward momentarily to a decent angle, then it would go back to a slower drag in a short time.
I was sorta thinking that a coarse 25 degree angle would help in start-offs and 'take-offs'. (getting to the point of cut-in)
But now I see that starting at 4 or 5 degree (blades almost straight up and down) as the other's say would allow the prop to 'coast' (keep spinning a decent rpm) very well when the small wind breezes go down to almost nothing. Which is what you want for low wind performance.
I did not know that at zero degrees the blades can keep going. That is good to know.
So the backward pitching goes from the 'normal set starting point' of 4 or 5 degrees to, say, NEGETIVE 5 degrees to basically 'air brake' when a big wind gust comes.
I am thinking of trying to do this for my small 6 footer. (but at a 700rpm or so since it is small)
- I had one small observation though--
I could be wrong, but I was looking at where the blade pitch axis is on his blades (up near the top upper side of each blade), and it seems to me that that placement would be more suitable for blades that pitch to feather forward.
Could that axis placement actually counter resist pitching backwards??
I would've probably put the pitch axis a little BELOW the center of the blade to pitch backwards easier. (maybe I'm looking at it backwards?/ It turns Counterclockwise right?)
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