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toekh
03-01-2010, 03:29 PM
I have bought an Sensenich ground adjustable composite propeller. It is meant to my Kitfox II with Jabiru 2200. I bought it because I need more static rpm to optimize start performance. My field is only 800 ft with a few obstacles in the end of the strip so it is a question about safety. I haven’t flown it yet and will return with a review.

http://www.wingman.se/archives/bilder/20091229_1.jpg

DesertFox4
03-01-2010, 03:39 PM
Great looking prop. Will look nice on your great looking Kitfox Tomas. Hope it works for you.

toekh
07-15-2010, 02:27 AM
At last I have tested my new propeller out for about 25 hours. As somebody say, it is a great looking prop, but I am a little bit disappointed on the result of testing.
Mounting and adjusting the prop is a piece of cake. You don’t need any instruments to adjust the angels of the blades. When you rotate one blade, the other follow to the same angel. This part of the test is very satisfying.
My reference in this test is a Jabiru wood propeller, 64" x 30", to a cost of one third of the Sensenich. I have flown the wood propeller for about 45 hours and was quite pleased with it. My reason to change was that I could only have 2.800 rpm from my Jabiru 2200 when I start and that means that I lost 15% of power according to the curves in the engine manual. I am operating from short fields and want to optimize my Kitfox for STOL performance.
The Sensenich propeller is 62" long and ground adjustable. I have tried all possible positions on my new prop and I can’t have the kitfox pop of the ground faster or even as fast as with my old prop... I have tried all angels given me from 2700 rpm to 3300 rpm at start. It doesn’t help. Best performance I can get is with an angel allowing the engine rotate 3000 rpm at full throttle when lifting off.

Same thing when test climbing. With the Sensenich prop my Kitfox climb out with 1000 ft/min at 3000 rpm, exactly the same as with my old prop at 2800.

The prop looks great and perform OK but I have expected more from a prop 15 years younger and 3 times more expensive than my old...

After 15 hours of flying I heard some noise from one of the propeller blades when I rotate it by hand. You could clearly hear that there were loose parts rattling inside the blade... I took contact with my local propeller dealer and he asked the Sensenich factory. They said that the symptoms I have described probably depends on that Sensenich inject drops of epoxy inside one of the blade when they weighing them together and that the drops can shake loose when using the prop. They told me not to worry and that the drops cannot do any harm.
So I keep on flying to end of season. When autumn start to be too windy for flying I send my propeller blades back to Sensenich in the states. I wonder what it will cost…

I have asked myself if the fact that the prop are 2 inches shorter than my old one could have a negative effect. Sensenich have a 64” prop for Jabiru but they only recommend it to the 3300 engine..? I wonder why? Jabiru 2200 are limited to 3300 rpm which means there are large marginal’s to 0,98 mach speed for propeller tips even with an 64” prop.

Thanks Tomas

N82HB
07-17-2010, 09:23 AM
I believe it is the blade design and not the length causing you problems. The RPM limitation on the longer prop could be due to stresses imposed on the hub and not a mach issue.

I have a warp drive 3-blade on my Kitfox IV with a 912S. I disappoints me on appearance, but excels everywhere else. Great performance and very cheap and seems to be very strong. It has not had any issues with rain like so many others do.