At 07:30 AM 3/14/97 -0800, you wrote:
>I must be misunderstanding how these servos are supposed to work.

They are only intended for 90 degree rotation.  The fact that they produce
270 degrees is due to the travel limits of the internal potentiometer.  If
you stay within 180 degrees, and away from a limit, you'll probably do fine.

Keep in mind, however, that not all brands, nor all models of Futaba, nor
even individual units, may provide the same performance when you are
running out-of-spec.  If you're only doing a one-off, you'll be just fine.

>I also figured the "center" was the middle of the shaft's output range,
>but you're saying that the center is wherever the shaft is when you're
>feeding the servo 1500uS pulses (which, since the output is linear in
>the 1000uS-2000uS range, is the midpoint of the linear range).

That's correct.  It shold be pretty close - how far off is it?

>[*] For what it's worth, my application is a camera platform with two
>servos mounted at 90 degrees to each other (left-right and up-down).  I
>can put the camera against a wall so that there's nothing behind it,
>but I still want it to be able to look all the way to the left and
>right, so I need a full 180 degree range of motion.

Interesting.  I had to do a pan and tilt for a video camera once, but it
had to be able to go round-and-round at whatever speed the operator wanted.
 Now THAT was fun!

Andy

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Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
          Hardware & Software for Industry & R/C Hobbies
        "Go fast, turn right, and keep the wet side down!"
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