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Old Oct 17, 2008, 12:37 PM
still learning
aeroknot's Avatar
west Georgia, USA
Joined Nov 2007
409 Posts
over in the flying wings forum, there was a thread about noise and pushers.

Several posters agreed that cutting out the edge in front of the lateral half of the prop reduced noise significantly. One person had semicircular cutouts on both sides of the motor mount, in front of the outer half of the prop.

I don't know if a micro-sumo is noisy with a 17 g motor, but when I build my micro-sumo, I'll see if I can make the slot wider on the outside than in the middle by cutting the edge in front of the prop at an angle, and leaving the back edge straight for CF support.
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Old Oct 17, 2008, 01:32 PM
still learning
aeroknot's Avatar
west Georgia, USA
Joined Nov 2007
409 Posts
Quote:
Originally Posted by REVKEV6
don't have any first hand experience with prop in slot setups, but the noise issues is due in large part to the two flat edges running parallel to the prop. It creates a pressure wave the causes noise. if you angle the the slot (make it diamond shaped for example) you should see a reduction in noise.
Kindof like what REVKEV6 wrote in post 7, only a bowtie shape, or some variant. I'll probably try the two semicircles along the lateral part of the front edge of the slot....
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Last edited by aeroknot; Oct 17, 2008 at 02:04 PM.
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Old Oct 17, 2008, 09:45 PM
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rich smith's Avatar
New Hampshire (not the old one)
Joined Dec 2006
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Edge beveling had relatively little effect compared to slot size and shape. The "dog bone" version on the right in my photo above was not as good as the "tail-less" one to the rear but was best compromise lift vs thrust.



Quote:
Originally Posted by aeroknot
Kindof like what REVKEV6 wrote in post 7, only a bowtie shape, or some variant. I'll probably try the two semicircles along the lateral part of the front edge of the slot....
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