2.5kg/cm torque means that the motor can pull a weight of 2.5kg when it is suspended at a distance of 1cm. So if you suspend the load at 0.5cm then the motor can pull a load of 5kg similarly if you suspend the load at 2cm then can pull only 1.25k.g
Tower Pro SG90 Servo Motor – 9g Mini/Micro Servo Motor
The Tower Pro SG90 9g mini servo motor�is the most commonly used servo motor in RC applications.
The servo motors are used for control applications which require precision control like robot arm positioning, tool position in machining equipment.
The servo motors usually provide control over 180° range. This angular position control is performed by PWM technique so by varying its duty cycle you can control the angular position of the motor.
This servo motor can lift a maximum of 1.6 kg when suspended at 1cm distance from the shaft. It can also be used in robotic arm, CNC machine, Steering systems on RC cars and other robotic or automation applications as well.
2.5kg/cm torque means that the motor can pull a weight of 2.5kg when it is suspended at a distance of 1cm. So if you suspend the load at 0.5cm then the motor can pull a load of 5kg similarly if you suspend the load at 2cm then can pull only 1.25
To make this motor rotate, we have to power the motor with 5V using the Red and Brown wire and send PWM signals to the Orange colour wire. Hence we need something that could generate PWM signals to make this motor work, this something could be anything like a 555 Timer or other Microcontroller platforms like Arduino, PIC, ARM or even a microprocessor like Raspberry Pie.
The PWM signal produced should have a frequency of 50Hz that is the PWM period should be 20ms. Out of which the On-Time can vary from 1ms to 2ms. So when the on-time is 1ms the motor will be in 0° and when 1.5ms the motor will be 90°, similarly when it is 2ms it will be 180°. So, by varying the on-time from 1ms to 2ms the motor can be controlled from 0° to 180°.
Applications
Used as actuators in many robots like Biped Robot, Hexapod, robotic arm etc..
Commonly used for steering system in RC toys
Robots where position control is required without feedback
Less weight hence used in multi DOF robots like humanoid robots
