180 deg servo?

Knut Eldhuset wrote in news:d1lvir$il4$ snipped-for-privacy@orkan.itea.ntnu.no:

I thought they all go at least 180 deg..?

I've done some experiments with an hitec hs-325hb ($14) and I got 180 degrees, no problems.

Padu

Nope, some do only 80 deg, and almost none are advertised as 180 deg. What you can achieve by controlling the servo with a microcontroller is another thing, which is why I ask :)

regards,

Often you will be restricted to 180 degrees when you hook it up to an R/C receiver, but when it's hooked up to a microcontroller there shouldn't be any limits short of the potentiometer's ones.

No, he's right. Most of the servos I've used (Hitec, Futaba, even Ace) can easily rotate 180 degrees, and these are the cheap ones, between $10-$15. Of course, this is the maximum range. The functional range depends on the controller, which typically limit rotation to 90 degrees.

Chris

I get about 190 deg rotation from a standard tower hobbies servo. My servo controller can operate it from hard stop to hard stop.

Thanks for that info. I'll try using one of my existing servos then. I have not tried hooking it up to the micro yet because of the small range I got with my RC gear.

regards,

possible

robotics,

money).

I've used 6-8 different servos from Cirrus, Futaba, Hitec, etc, and they all rotate over 180 deg. However, it seems that most R/C receivers will limit the rotation to only 90 deg or so. Also, if you use a servo controller chip to run the servos over the full 180 deg range, you'll find the angle-vs-pulsewidth relationship is not quite linear. You normally get 90 deg rotation with pulses over 1000-2000 usec, but typically the full 180 deg comes over a pulsewidth range of about

- dan michaels