This tutorial is intended to complement the Robot Arm Torque Calculator found in the Dynamic Tools section of GoRobotics. The equations used in the calculator to determine the torque required at any given lifting joint (raising the arm vertically) in a robotic arm are presented h…

Hi @cbenson . First off, thanks for this article. Your response in this post ( Sum of moments ) is quite close to what I’ve been looking through the forum for (as is this article itself). I wonder if you could expand a bit more to help me out with something. Without getting too en…

Like you said, the sum of the torque equals the (sum of) moments of inertia multiplied by the angular acceleration. Keep in mind the moment of inertia of a point is different when it’s at a distance from the axis of rotation (where you’re taking the torque). You need to factor in…

@cbenson All sounds good. Thanks for taking the time to reply - much appreciated.

Hi, thanks very much for this tutorial – extremely helpful. I’m designing a final arm segment joint (the one that rotates the end effector) to be implemented with an RC style servo which allows attachment of a C clamp across the servo body (as you recommended here: Building robot…

@Robo_Matt To confirm, you’re worried about the axial load on the servo’s output shaft (i.e. the direction which would otherwise remove the servo’s horn)? Unfortunately most RC servos are either supported along the z-axis using plastic, plastic ball bearings or metal radial ball …

Hello, can anyone provide some insight on the following. when some of joints are required to hold its position, the resulting velocity and acceleration will be zero: How is the controller model estimating the required torque to hold the position? It would be really helpful, i…

@aashish05 Welcome to the RobotShop Community. The equations used here are purely static situations (as you describe) and don’t factor in acceleration or deceleration. It calculates a “worst case” torque at each joint where the arm is horizontal, holding a load at full reach. How…

Hi @cbenson . First off, thanks for this article. How can I determine the angular acceleration of each rotating joint with the problem that the acceleration of the ending effectors is always set to 1.2 m / s ^ 2? I do not really understand the factor of safety that you default to…

@NMC Welcome to the RobotShop Community. How can I determine the angular acceleration of each rotating joint with the problem that the acceleration of the ending effectors is always set to 1.2 m / s ^ 2? Can you explain a bit more? The 1.2m/s^2 is your own requirement? If so,…

Robot Arm Torque Tutorial

Let's Make Robots Tutorials

Robo_Matt May 3, 2019, 11:20pm 78

Thanks for your help cbenson! As suggested I’ve created a new forum post:

( Perpendicular Gravity Torque on Horizontal Rotating Arm Servo)