Arduino Forum

Products => The Arduino Starter Kit and Basic Kit => Topic started by: longstaff on Jan 27, 2013, 04:03 pm

Title: Servo motor range only 90 degrees?
Post by: longstaff on Jan 27, 2013, 04:03 pm
In the text the servo motor is supposed to give 180 degree of motion, even suggesting cutting out a "half circle" to make the dial on.
My servo is only giving me 90 degree motion, which is supported by the picture on page 69 giving only a quarter circle for the dial.

Anyone know which one is supposed to be correct? or which is working for you?
Title: Re: Servo motor range only 90 degrees?
Post by: retrolefty on Jan 27, 2013, 04:22 pm

In the text the servo motor is supposed to give 180 degree of motion, even suggesting cutting out a "half circle" to make the dial on.
My servo is only giving me 90 degree motion, which is supported by the picture on page 69 giving only a quarter circle for the dial.

Anyone know which one is supposed to be correct? or which is working for you?


Not all servos can actually move a full 180 degrees, that is just an assumption the arduino servo library uses. Perhaps a link to your specific servo may shed light on the topic?

Lefty
Title: Re: Servo motor range only 90 degrees?
Post by: longstaff on Jan 27, 2013, 04:29 pm
the servo is the one that is included in the starter kit.

on further study there is an obvious number on it that is a product code (SM-S2309S) that states movement of about 60 degrees on the data sheets, so its just incorrectly stated in the book.
next time I might actually look at the component...

Thanks
Title: Re: Servo motor range only 90 degrees?
Post by: retrolefty on Jan 27, 2013, 04:45 pm

the servo is the one that is included in the starter kit.

on further study there is an obvious number on it that is a product code (SM-S2309S) that states movement of about 60 degrees on the data sheets, so its just incorrectly stated in the book.
next time I might actually look at the component...

Thanks


Well the datasheet I found doesn't give the total travel range. http://www.servodatabase.com/servo/springrc/sm-s2309s

The spec listed:
Quote
4.8V: 0.12 sec/60°
6.0V: 0.10 sec/60°


Is a speed specification telling how many degrees it can move in so much time at what operating voltage.

The total range specification is shown as:

Quote
Rotational Range:   ? (add)


Lefty
Title: Re: Servo motor range only 90 degrees?
Post by: JohnClavis on Apr 27, 2013, 04:34 am
That's the exact model # of the servo listed on the arduino website (arduino.cc)! You can read the # on the sticker on the photo of the servo! Just look up "servo" -- there's only a couple! They list the range of movement as 180 degrees! It's right there on their site! I'm about to order one based on the assumption that it's accurate! I hope it is!
Title: Re: Servo motor range only 90 degrees?
Post by: Stefano2800 on Feb 07, 2015, 03:35 pm
I have found this datasheet: http://descargas.cetronic.es/microservo.pdf
apparently total range is 120°
Title: Re: Servo motor range only 90 degrees?
Post by: Stefano2800 on Feb 12, 2015, 02:35 pm
I tried my sevo, from the Starter Kit, it moves almost 180°
But I was thinking that, if you reference the movement of your servo to a voltage, like in the Project05, when you map the voltage values and angles you assume that the output of the pot will be 0 to 5Vdc.
Well make sure it happens, maybe for some reasons you have lower maximum output and so you will never get to 180°, in this case you have to remap using the max voltage you can  get...
Probably it is not your case, but it may help someone else in future...
Title: Re: Servo motor range only 90 degrees?
Post by: JoseSolanoCR on Feb 27, 2015, 05:45 am
may be i am a little late with this... but i was at the same point with the servo of my arduino kit.... "almost" 180 degrees.... after a short (long) reading and testing... used this on my code...


void setup()
{

  servo1.attach(7);
  servo1.writeMicroseconds(2300);
 

}

this  function actually make my servo turn 180 degrees....