Originally Posted by
riot3d
Test flown the 185 this morning, first flight with a 20.5 x 10 PN, about 7,000 on the ground with slightly rich setting. Changed to a 20 x 10.5 PN from the second flight on to put in more flight & break in time before switching back to the bigger prop. First impression, very effortless for up line & good, slow down line. After about a 9 minute flight on P-15 & a few F maneuvers, it still has slightly less than half a tank of fuel left on a 600cc tank. Since the whole morning was pretty calm, it will be interesting to see how much fuel it'll consume on a windy day. Will fly again tomorrow for more evaluation.
Adrian
Adrian, I've been using the same prop on the OS GT33 gas engine. I get practically the same numbers as you indicate with the 33 also brand new.
It's a terrific prop except for its weight. 175 grams is a bunch. I made a wood carbon hybrid which weighs about 77 grams and similar in size.... 20 1/4"x12". I narrowed the blades 1/16" compared to the APC and thinned them compared to the APC, but otherwise the planform of the blades is identical to the APC. Paid very close attention to the trailing edge of the new prop, making is as sharp as the APC. The results are outstanding. Picked up rpm and the thrust from the 12 pitch is noticeable.
If you want to tackle the project, lets talk in private