On Tue, 23 Jul 2002 12:35:53 -0400, Sean H. Breheny wrote:

>I've been looking at electric motors for use in small=
 autonomous
>flying vehicles (I do research in these at Cornell University)=
 for
>some time. I have been using the ratio of maximum rated output=
 power

>I am an RC hobbyist myself and I have a great respect for what=
 is
>achieved in the hobby world, but I do find it hard to believe=
 that
>the hobby world is able to achieve motors that outperform the=
 best
>industrial motors by a factor of 10 in some regard. I'd like to=
 find
>out if perhaps there is some other drawback to the hobby motors=
 or
>if perhaps they arrive at their maximum rated power spec=
 differently
>which would explain part of the factor of 10.

The high end motors built for RC use (Aveox, Astroflight, MaxCim,=
 etc.)
are not rated for 100% duty cycle at their stated capacity. Most=
 are
designed with flights of 3-7 minutes at full power in mind. They=

sometimes go to extremes to reduce weight, knowing that the=
 battery
system can only deliver a certain amount of energy before a=
 mandatory
cooling off period. Some of the really high end motors for racing=
 use
don't even have full metal cans, they use molded Kevlar, etc.=
 which
makes them light.

Tim

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