High Torque Motor - Low RPM
High Torque Motors
High torque motors are practically just a regular, internally commutated brushless DC Motors mounted with additional gear mechanism on top, to either increase the torque or to reduce the RPM (Revolutions per minute). These DC motors are quiet powerful and can be used in several hobbyist and industrial application, also one of the standard motors for most of the robot chassis. We are going to use these motors for our tutorial robots.
Reducing the RPM while maintaining high torque would require adding up more complex gear mechanism hence the cost of these High torque DC motors mostly depends on the RPM, torque and quality of the motors.The motor shaft from the base motor though a transmission connects the small gear box fixed at its front portion, which in turn generates the necessary torque while keeping the RPM low, the entire gears and gear heads are doped with thick viscous grease lubricant.
These High torque Motors come on various RPM's such as, 5 RPM, 10 RPM, 100 RPM, 300 RPM, 1000 RPM and so on. The cost of these geared motors is based on the RPM, usually lesser RPM costs more than those of higher RPM. Most of my motors are from Amazon.
If you are in India then you can buy 3 of such Low RPM dc motors with cost of one stepper motor.
High torque and low rpm DC motors are ideal for robotic and hobby applications, thought the size of the motor is a matter of concern because it is quiet large in size due to additional gear box but still it would save the trouble and cost of adding external gears to the assembly of robots where just the regular DC motors wouldn't do well. The High Torque, Low RPM DC motors comes with inbuilt gearbox mechanism providing necessary torque for your robotic application. Hence these motors would be the most favorable choice for the hobbyist robotic projects and tutorials posted here.
For various automation and robotic projects, where the cost of servo and stepper motor seems a bit expensive, these High torque low rpm DC motors can be used as an alternative where not much degree of controls are required. If you are making a robot where you don’t need complex maneuvering (like the one you can achieve with servos and Stepper motor) then you can you these high torque low RPM DC motors are good alternative because it is quiet cheap or inexpensive then that of the Stepper Motor's and servos.
Pictures below show the internal anatomy of the gear box of a high torque motor. The entire internal gear mechanism is doped with thick viscous grease lubricant.
These High torque Motors can be easily found in any electronic stores and online. The cost of these motors depends on the torque, quality of the base motor, Voltage and RPM (revolutions per minute), the lower the RPM, higher the price.
Most of the robotic application published in this site uses either a 20 RPM or 5 Rpm DC motors, which is not only a cost effective measure but also requires less complex coding as compare to Stepper and Servo motors. These motors can be easily interfaced with L293D motor driver or uln2003 to interface with any kind of microcontroller.
Shown below is a an example of a Simple High torque Motor, 5-RPM.
Also See : Differential Steering Designs
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