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Old Oct 30, 2010, 05:07 AM
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Nominal prop pitch is generally measured at 75% of the blade so the nominal pitch will certainly increase.

The problem is that a prop blade is also doing most of the work between 50-80% of the blade. The blade camber and thickness will have been optimised at this point.

The tip 20% of the blade, however will be optimised for best efficiency in spite of tip losses.

Chop off 25% and you will have the wrong shaped camber and too much thickness in the new 'tip' so you'll lose alot of efficiency. In other words the bit that was doing the work before is now the tip, with all the losses that means.

By chopping off the tip you obviously lose the lift from the bit you cut off, but you also mess up the efficiency of the part that made all the thrust.

That said, it will still make thrust, but the lack of efficiency will quite possibly obviate any other gains.

By all means try it, but be prepared to bin it!
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