Mailing List flyrotary@lancaironline.net Message #56438
From: Scott Emery <shipchief@aol.com>
Subject: Re: [FlyRotary] Re: Props
Date: Sun, 28 Aug 2011 21:12:27 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Paul Lipps designs some radical props. He has a convincing argument in favor of more blades but less diameter. Less dia. Means less torque arm for tip drag / blade. More blades : more thrust.

Sent from my iPhone

On Aug 25, 2011, at 2:45 PM, Dale_R <dale.rog@gmail.com> wrote:

I can't speak from direct experience - yet - but the reason I'm planning on a Hertzler Silver Bullet is that several people have found that Gary's two blade had outperformed the Catto they had made for the same application.  For example, Marc Zeitlin found he liked his new Silver Bullet better than the three blade that he'd had before.

Problem is, one of those "other factors" is that for any given output, two blade usually has to be longer than a three blade.  Too long on a pusher and it gets trimmed automatically on your first high-angle-of-attack landing.

Dale_R
COZY MkIV #0497


On 8/25/2011 1:53 PM, Tracy wrote:
Most efficient would be 2 blades.   other factors may favor more blades but that's a different question.

Tracy

On Thu, Aug 25, 2011 at 4:25 PM, Samuel Treffinger <samuel.treffinger@gmail.com> wrote:
Hey, what would you recommend? A three or four blade prop? It will be wood, so weight isnt such an issue, but which is more efficient given the same power?
 
Sam



-- 
Dale_R
Cozy MKIV #497
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