Alt-BEAM Archive
Message #10461
To: beam@sgiblab.sgi.com
From: Bob Shannon bshannon@tiac.net
Date: Sat, 19 Feb 2000 11:07:47 -0500
Subject: [alt-beam] Re: solarbotics pager mtr+fan
Dave Hrynkiw wrote:
> At 11:38 PM 2/18/00 , Timothy Flytch wrote:
> >Only if the axels or coaxial... if you separate the blades then you do not
> >have to use counter rotating blades to counter act tork... you use an
> >offset or tilt of the blade disk to counter tork...
>
> I disagree. If this were true, then many twin engine aircraft wouldn't be
> going through so much effort to have props spinning in opposite directions.
Ahhh, twin engine aricraft most often have props spinning in the same
direction.
In General Avation (I'm a pilot) the only light twin that does not have props
spinning
in the same direction is the Cessna 336/337, with a pusher and puller in-line
configuration.
If you get your twin engine certification in this type of plane, you get a
special
restriction, called center-line thrust only on your licensse.
> Engine torque is a (counter)useful tool to turn aircraft in one direction
> harder than the other.
Which is why the engine is not mounted parallel to the centerline!
But its very true, prop driven aircraft LOVE to turn left, but are reluctant to
turn right
(for US made engines that is).
> Just like in any other physics system, the sum of the forces must be zero;
> if there isn't an equal and opposite torque from the motors, it's going to
> come from with resistance with the surrounding air, and produce rotation
> effect.
>
> -Dave
>
> ---------------------------------------------------------------
> "Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
> that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
> 2 vowels. Pronounciation? _SMITH_".
> http://www.solarbotics.com
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