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ASM
04-10-2011, 07:50 PM
Hi
I have a ranging sensor mounted on a HiTec HS-311 servo. I have done some programming to take readings every 5 degrees using Arduino's Servo library. My question is, does the servo precisely orient to 15 deg when i ask it to? Because from what i've seen, 0 deg doesn't at all seem like 0 deg. Also 180 deg doesn't at all seem like 180 deg. Only 90deg seems precise.

vikas
04-11-2011, 01:07 PM
The precision of a servo depends on it's electronics. Most servo's use a simple potentiometer for feedback, so they are not usually completely linear. Most also have a certain amount of play in the gears, and accuracy goes down with age.Also the driving PWM plays a factor too. And repeated twice the same angle will not be the same exactly due to errors due the above mentioned factors.

You can improve it though

http://www.geology.smu.edu/~dpa-www/robo/servo/servohac.htm
Or adding other form of external feedback.