The Prop windmilling on RX1/Apex engines

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Pilot-34

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Well I decided that to be fair I should cut a disk of cardboard the size of the propeller.
 

Tiger Tim

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Interesting . How does a stopped prop effect the trim different than freewheeling.
The prop on a rubber model is quite exaggerated compared to what you’d use on pretty well anything else, so they tend to be large diameter with broad blades and coarse pitch. With their prop locked in flight the blades effectively act as ailerons. I’m sure it’s nothing that couldn’t be trimmed out but once a free flight model leaves your hand there’s no way to do that.
 

Pilot-34

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And the results are in!

Using a small RC airCraft propeller

And a carefully calculated arm to measure forces.

I can detect no significant difference between the propeller stalled , or freewheeling and the cardboard disk which bent in half.

My personal biases may have affected the outcome but any of you are more than welcome to repeat the experiment
I suggest larger equipment and a more precisely calculated Measuring device
 

BBerson

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The prop on a rubber model is quite exaggerated compared to what you’d use on pretty well anything else, so they tend to be large diameter with broad blades and coarse pitch. With their prop locked in flight the blades effectively act as ailerons. I’m sure it’s nothing that couldn’t be trimmed out but once a free flight model leaves your hand there’s no way to do that.
Thanks. I thought it might have been a pitch trim issue.
 

Patrick Wehling

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Apr 2, 2020
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There was a review of gliding distances windmilling and prop stopped on several Kitfox airplanes. Think Trent Palmer. They found little difference.
 
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