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Help with props?

Old 06-08-2005, 08:16 PM
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Rv7garage
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Default Help with props?

I'm currently running an O.S. 70 fourstroke with a 13x6 prop, and it runs great. I want to put this motor into a different plane, and I will need to go with a smaller diameter prop because of ground clearance issues. What pitch would I use on an 11" prop to get equivalent performance (or at least close to it)? Thanks in advance.
Old 06-08-2005, 08:42 PM
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WS
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Default RE: Help with props?

thats a pretty significant drop in diameter! You'll need close to 12 pitch to keep the rpm down. Another option would be to go to 3 blades. I'm thinking a Graupner 11 x 7 3-blade might be your prop!
Old 06-08-2005, 08:48 PM
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Pilot Chad
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Default RE: Help with props?

3 blade is your best way to go for this..
Old 06-08-2005, 09:03 PM
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Rv7garage
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Default RE: Help with props?

Meh....

Guess I'll just bite the bullet and get that Super Tigre G51 that I've been looking at, and save the fourbanger for another plane. Hell, the G61 is only $5 more, I know this is an aerodynamics forum but I wonder if its actually a good engine for as cheap as it is? Hmm...[8D]
Old 06-08-2005, 10:34 PM
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Default RE: Help with props?

Yes!

[8D]
Old 06-09-2005, 12:41 PM
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DTB
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Default RE: Help with props?


ORIGINAL: flycfii

I'm currently running an O.S. 70 fourstroke with a 13x6 prop, and it runs great. I want to put this motor into a different plane, and I will need to go with a smaller diameter prop because of ground clearance issues. What pitch would I use on an 11" prop to get equivalent performance (or at least close to it)? Thanks in advance.
As far as loading the engine, a 11x10 would put roughly the same load on the engine, but would fly you a lot faster and won't be great for 3D, but for normal flying it should be ok but will be faster than what you have now.

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