Specification and Motor Type of a Servo

Posted on 04 Dec 2012 by RC-Fever.com  

 

How to choose a suitable servo? What critrea we need to take care on? What different between servos? After reading this post you must know much more.

Digital and Analog Servo: Digital servo's processor transmits about 300 pulses per second while analog servo's transmits about 60 pulses per second. In the post of "Information about Analog Servo and Digital Servo" you can see digital is not a must as digital servo consumes more power and need to see which type of RC toys that you are playing.

Weight and Dimension: This is the physical criteria of servo. You need a suitable size and weight servo to match your RC toys, not too big and not too heavy.

Torque: It means the maximum force the servo can provide, the unit of the servo's torque is kg/cm, bigger means stronger. But what this unit means? It means when you using a 1cm long servo arm on this servo and it can provide that much kg of force. Then how about when I use a 0.5cm servo arm? The force will double of course.

Speed: It means the rotating speed of the servo, the unit of the servo's speed is sec/ 60°. Take a 0.1 sec/ 60° servo as an example, it only need 0.1 second to rotate for 60°. acrifice Some helicopter flight tricks need a very fast servo to achieve.

Motor Type: 3 or 5 Pole Motors - This refers to the commutator in the motor. The commutator is where the brushes make contact with the armature. The more motor poles the smoother and more accurate the servo will operate. Most servos have either 3 or 5 pole commutators. Brushless Servo Motors – Just as it's name, it use a small brushless motor in the servo, as brushless motors are more efficient, provide more power, speed, and acceleration.

Rotation and Gear material: Servos use a few methods for rotation platform: single bearing, dual bearing and some use bushing. Gear material has a few to choose for example plastic, metal and titanium, where plastic may not a bad choice as its sacrifice may protect the electronic parts of servo. The hard gear can use fragile servo horn to protect the servo.

I found a good website showing many data of servos and you can use as a reference and buy a suitable servo from RC-FEVER.