Tham khảo tài liệu 'mcgraw-hill - the robot builder's bonanza part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | TYPICAL SERVO SPECS 301 Typical Servo Specs R C servo motors enjoy some standardization. This sameness applies primarily to standardsized servos which measure approximately inches by inch by inches. For other servo types the size varies somewhat between makers as these are designed for specialized tasks. Table outlines typical specifications for several types of servos including dimensions weight torque and transit time. Of course except for the size of standard servos these specifications can vary between brand and model. A few of the terms used in the specs require extra discussion. As explained in Chapter 17 Choosing the Right Motor for the Job the torque of the motor is the amount of force it exerts . The standard torque unit of measure for R C servos is expressed in ounce-inches or the number of ounces the servo can lift when the weight is extended one inch from the shaft of the motor. Servos exhibit very high torque thanks to their speed reduction gear trains. The transit time also called slew rate is the approximate time it takes for the servo to rotate the shaft X usually specified as 60 . Small servos turn at about a quarter of a second per 60 while larger servos tend to be a bit slower. The faster the transit time the faster acting the servo will be. You can calculate equivalent RPM by multiplying the 60 transit time by 6 to get full 360 rotation then dividing the result into 60. For example if a servo motor has a 60 transit time of seconds that s one revolution in seconds .2 X 6 or 50 RPM 60 50 . Bear in mind that there are variations on the standard themes for all R C servo classes. For example standard servos are available in more expensive high-speed and high-torque versions. Servo manufacturers list the specifications for each model so you can compare and make the best choice based on your particular needs. Many R C servos are designed for use in special applications and these applications can be adapted to robots. .
