Alt-BEAM Archive
Message #10488
To: beam@sgiblab.sgi.com
From: CIRCITZ@aol.com
Date: Sat, 19 Feb 2000 21:02:53 EST
Subject: [alt-beam] Re: FYI: ANN: fire-fighting robot contest at Penn State (3-25)
Well this actually does sound like it would be fun, and they've only got 4
bots in the competition so far...Are you suggesting we make a team? Cuz I'd
be all for it, although your idea of multi-bots didn't seem like it applied
to this contest on the 25th. I'm right in Philly so it's pretty close for me.
If you or anybody else is honestly interested we better hurry with only a
month left, so you can either keep this on the list or you can email me
directly at
CIRCITZ@AOL.COM
Dan
<< http://www.ecsel.psu.edu/~avanzato/robots/contests/
>>
10489 Sat, 19 Feb 2000 19:43:09 PST [alt-beam] Re: solarbotics pager mtr+fan beam@sgiblab.sgi.com "Timothy Flytch" No Dave... they use counter rotating props on modern aircraft to allow
single engine operation... Trust me I've studied aerodynamics for over
twenty years...
if you would like to discuss this feather lets do it off list. ok?
Timothy...
>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.
>Engine torque is a (counter)useful tool to turn aircraft in one direction
>harder than the other.
>
>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
______________________________________________________
10490 Sat, 19 Feb 2000 22:26:32 -0600 [alt-beam] Re: FYI: ANN: fire-fighting robot contest at Penn State (3-25) alt-beam@egroups.com Ben A Micklin Hey, howabout you have 1 large autonomous robot, and 4 little ones. upon
raching a certain destination, the large robot "launches" all other 4
robots, which are controlled by r/c, and they begin to search out. they
talk to the large 'bot, telling it where the fire is, and when one tiny
'bot does, it immediatly sends out a "distress" call , and all other
robots are immediatly sent to that area to help the one who found it put
out the fire. Does this sound
good?
~ben~
On Sat, 19 Feb 2000 21:02:53 EST CIRCITZ@aol.com writes:
> Well this actually does sound like it would be fun, and they've only
> got 4
> bots in the competition so far...Are you suggesting we make a team?
> Cuz I'd
> be all for it, although your idea of multi-bots didn't seem like it
> applied
> to this contest on the 25th. I'm right in Philly so it's pretty
> close for me.
> If you or anybody else is honestly interested we better hurry with
> only a
> month left, so you can either keep this on the list or you can email
> me
> directly at
> CIRCITZ@AOL.COM
> Dan
> << http://www.ecsel.psu.edu/~avanzato/robots/contests/
> >>
>
>
------------------------------------------------------------------------
> -- 20 megs of disk space in your group's Document Vault
> -- http://www.egroups.com/docvault/alt-beam/?m=1
>
>
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10491 Sat, 19 Feb 2000 20:23:55 PST [alt-beam] Re: electric helicopters are getting close... beam@sgiblab.sgi.com "Timothy Flytch" New World Record!
On August 17th in 1996 Norbert Gr?ntjens established a new world record in
duration flight with primary cells. At the company's own site he landed an
ECO 8 safely after an flight of 63,29 mins. The previous record was 21 mins.
Yes Jim, this blows my mind... I've flown electric planes off and on since
1976... And ...WOW....
Thanks for the links...
Timothy...
> >>but how many "micro piezo
> > >gyros" have you seen for sale?
>TONS AND TONS!
>I get mine for a mear 45 dollars! full control circuitry included.
>http://www.ikarus-modellbau.de/Ikarus/english/index-gyro.html
>
>http://www.ikarus-modellbau.de/Ikarus/english/seite-eco-familie.htm
>
______________________________________________________
10492 Sat, 19 Feb 2000 21:34:33 -0700 [alt-beam] Re: solarbotics pager mtr+fan beam@sgiblab.sgi.com Dave Hrynkiw At 08:43 PM 2/19/00 , Timothy Flytch wrote:
>No Dave... they use counter rotating props on modern aircraft to allow
>single engine operation... Trust me I've studied aerodynamics for over
>twenty years...
>if you would like to discuss this feather lets do it off list. ok?
Ditto, but in an informal sense. Model aircraft enthusiast, started
Aeronautical engineering, finished in Mechanical.
Counter-rotation indeed does help one-engine-out scenarios, but you simply
cannot have a "free lunch" when it comes to torque. One or two motors,
there has to be something counter-acting the force of the prop against the
air, be it a rudder, offset engine thrustline, or another torque source
acting in the opposite rotation (ie: 2nd engine reverse rotation).
That said, if you wish to pursue this further, offline it is....
Regards,
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
10493 Sat, 19 Feb 2000 20:58:02 -0800 [alt-beam] Re: solarbotics pager mtr+fan alt-beam@eGroups.com "Ken Hill" On the original theme - I played with mini (Tyco?) slotcar motor/gear
setups
a while back that did have enough thrust to go vertical (less power
supply).
I just put a rubberband model plane's prop on the axles - mounted one
on each
end of a stick of balsa. It had the thrust, but no control. Thought
I'd rig
a joystick linking the throttles of both motors to one control. Could
go with
4 and RC or even BEAM it? :)
Ken Hill
http://www.acesim.com/
home of the JoyRider Flight Motion Simulator
dave hrynkiw wrote:
original article:http://www.egroups.com/group/alt-beam/?start=10492
> At 08:43 PM 2/19/00 , Timothy Flytch wrote:
> >No Dave... they use counter rotating props on modern aircraft to
allow
> >single engine operation... Trust me I've studied aerodynamics for
over
> >twenty years...
> >if you would like to discuss this feather lets do it off list. ok?
>
> Ditto, but in an informal sense. Model aircraft enthusiast, started
> Aeronautical engineering, finished in Mechanical.
>
> Counter-rotation indeed does help one-engine-out scenarios, but you
simply
> cannot have a "free lunch" when it comes to torque. One or two
motors,
> there has to be something counter-acting the force of the prop
against the
> air, be it a rudder, offset engine thrustline, or another torque
source
> acting in the opposite rotation (ie: 2nd engine reverse rotation).
>
> That said, if you wish to pursue this further, offline it is....
>
> Regards,
> Dave
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