Questions tagged [torque]
Torque, moment, or moment of force is the tendency of a force to rotate an object around an axis, fulcrum, or pivot.
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Finding torque equation for my robotic arm
I am designing a 5 dof robotic arm, and for that I would like to find a torque equation. However, I am a little confused here:
According to me the torque equation for M1 should be l2m2+l3m3+l4m4+l5m5 (...
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Power pack and servo driver for robotic arm?
I have a robotic arm that uses about eight 7.4 volt volt high torque servos. (https://www.servocity.com/2000-series-dual-mode-servo-25-2/)
I need to know what Kind of battery system I can use to power ...
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I’m not sure how to calculate the torque of a tank chassis what values do I need?
So I plan to build a robot-tank thing. It’s max weight will be 35kg and it’s driving wheel will have a radius of 0.05m. Those are the two values I know for certain and there will be no gears between ...
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How to choose a servo motor for solar tracking mechanism?
I design a solar tracking mechanisim. You can see the very undetailed representation in the pic. For choosing a servo motor how can I calculate the torque etc?
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Calculate Torques & Forces From Jacobian Matrix
Dear Robotics Stack Exchange,
I am trying to calculate the torques and forces for a 2DOF robot.
I’m used the partial differentiation method to find the Jacobian matrix. I managed to find the ...
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84 views
Torque required to rotate arm with mass at end
I have to calculate the required torque to rotate a point mass of 15N on the end of an 1.2m long arm which I have calculated to be 10kg in mass. The rotation must have a constant angular velocity of ...
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51 views
Do hobby servos respond to step inputs with a step in torque?
I'm designing a piston that I need to expand a few cm in <100ms to load energy into a spring-mass system with around a pound of force (as shown below). Based on power specs alone, high-end hobby ...
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26 views
Force-torque sensor reading when a robot is stationary
Let's say I have a robot arm with a force-torque sensor on the wrist, between the final motor and the gripper. If the arm and wrist are stationary, then what would the reading on the sensor be?
I know ...
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Quadrotor dynamics: How is torque created
I'm a software engineer and I've recently engaged into Robotics field. I've started by a course on Coursera which talks about Aerial robotics and thus quad-rotors. I'm trying to understand how quad-...
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59 views
Can I measure torque from this motor by only measuring the current?
I am new to robotics, please forgive/correct any errors.
My Project Plan
I want to use a PID controlled motor in a human-interface device where I need to measure the user's exerted force on an end ...
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36 views
What is the most accurate method to calculate Torque of 5 DOF Robotic arm
I am working for development of a 5 DOF Robotic arm , and I am confused in the Torque calculation
This is a 5 Axis revolute Joints Robotic arm , where Motor for 1st axis will rotate the turning table ...
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66 views
When not to use pseudoinverse?
I know this equation: $\tau = J^T f$. In my case, the Jacobian $J$ is not square. Is it valid to use the pseudoinverse of $J^T$ to calculate end effector forces $f$ based on joint torques $\tau$? I ...
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39 views
Calculate body speed in m/s with weight in the equation?
UPDATE: I have clarified my question for answerers to better understand what I am asking
If I have a flywheel, like the one shown in this image, and I know the torque, weight distribution, and weight. ...
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23 views
How to convert torque in oz-in into the weight it can withstand?
I am looking at servos to make a robot claw, and I want to make sure the one i am getting can turn under a specific amount of weight. The servos specify their torque in oz-in. I am not sure how to ...
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No electric motors can handle being stalled for even short periods of time, even at low power. Is this statement true in all cases?
We were using a regular POLOLU d.c motor whose stall current is 0.36A. We want to use this motor in a robotic hand where the motor will be stalled while holding the object. We are limiting the current ...
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Determining required torque for DC motor
How to determine the required torque while choosing a DC motor?
Here is a simple scenario. Think of a 4WD or 2WD vehicle. The max load the vehicle will have is 100kg.
Q1. How do I determine the ...
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Why aren't my 4x 612 RPM motors driving with only 12 lb load?
I have purchased x4 612 RPM actobotics motors. Every time I try to drive the motors on ground, the motors stall, as if the torque was too low to drive.
The motor model: servocity.com model #: 638284 ...
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Controlling high torque servo motors with Raspberry Pi
I need to control 10 Standard Servo Motors (operating at 4.8-7V/300mA-1A/2.5kg-5kg torque) in my project. I'm using RPi as my processor and I was looking for a servo driver. I came across PCA9685 16-...
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68 views
Counterweight in arm designs
I wonder why most robotic arms use large J2 (shoulder) motors rather than counterweights. What sort of complexity do they add to the design beside increase in overall weight? In fact, rather than ...
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Understanding KGf.CM in Camera Robotic Head Design
I am attempting to design a robotic camera head - however, I am struggling to calculate the torque (in terms of KGf.CM) I will require to rotate the Y (tilt) axis of the head.
The motor I intend to ...
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How to calculate what motor I need to move weight
I'm working on a project trying to make some electric roller curtains.
I can use 2 motors on this curtain, on each side to lift and pull down the curtain. Pulling down the curtain requires not as much ...
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Singular Configuration - Balanced Wrench F?
I've been asked to show that if a manipular is at a singular configuration, then the End Effector wrench can be balanced without any joint torques.
I know that t = J*F where (t = torques, F= end ...
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39 views
How is this torque value arrived?
I'm going through this person's torque calculation of a simple crane setup. the servo used has a max torque of 57oz.in:
At the top, if Mservo is 34.12oz.in, how is ...
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96 views
Rotating a lever with a small servo
I'm trying to rotate a lever link to gently "offload" a load using a servo. Here's a drawing:
Here, the red is a lever, yellow pivot and black is the load. To offload, the lever needs to be turned 90 ...
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How to make a diff robot (2 traction wheels front and 2 castor wheels back) to go straight?
I’m developing a differential robot. My wheeled robot has two castor wheels in the back and two driven wheels in the front. The motor controller I’m using can handle two motors each with 90 cpr. Each ...
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101 views
Sensing torque of stepper motor
I need to sense the torque of a stepper motor at any given time. I'm planning to tension a wire by using a stepper motor, and in order to keep the wire at a fixed tension I would need to know the ...
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1answer
145 views
Servo motor torque
I am confused with the torque ratings of servo motors, or I guess it is general while choosing any motor.
For example a servo's torque is rated as 10kg-cm, so does that mean it can handle a 100N ...
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1answer
770 views
Specification calculation for choosing a proper stepper motor for Ball Lead / Screw system
I'm trying to build a motorized stage which moves in one direction as below picture based on this article.
Desired characteristic properties are:
1. screw length = 150 mm
2. screw diameter = 14mm
...
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1answer
49 views
How can a motor be run at higher voltage for longer?
A 12V windshield wiper motor to run at 24V for more speed but near-equal driving force.
Testing with a variable DC supply between 21.6V & 26.4V showed the current maxes at 3.72 - 3.90A, as ...
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Torque Disturbance Observer for Manipulator Arms
Is there a tutorial/guide apart from the research papers ( paper 1 and paper 2 ), for implementation of torque disturbance observers on multi-DOF robotic manipulators to determine sudden collision ...
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Jacobian of a 6DOF arm
I have a robot with 6 DOF. I read a lot of tutorial on how to compute the Jacobian, but usually all examples are for planar robots with 2DOF.
I don't understand how can I get the Jacobian of a 6 DOF ...
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431 views
How to calculate effort/torque values of a joint
I have a robotic arm with 6 DOF. For each joint, I get get the Joint Wrench, which is composed by the force and torque of the parent and child links of the joints. In other works, for joint 1 I can ...
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907 views
Calculating torque required to rotate a platform
I am trying to spec out a motor's torque required to rotate a platform about an axis.
This diagram makes it better to understand(it's like a rotisserie):
Dimensions are in cm:
I have an arbitrary ...
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1answer
105 views
Practically implementing a torque controller
I'm currently working on a robotics project where i have to build a quadruped. i have somewhat finished the designing for the time being and now moving into simulations. I have followed a inverse ...
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What servos are suitable for a robot like Boston Dynamics’ Atlas?
I have seen Boston Dynamics’ robot Atlas do some pretty impressive things, like a backflip, which must put quite large torques on the servomotors.
What servos are there that can generate torques like ...
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263 views
DJI E310 Thrust Coefficient
I am reading Denis M. Filatov et al.'s paper "Parameters identification of thrust generation subsystem for small unmanned aerial vehicles" (https://www.semanticscholar.org/paper/Parameters-...
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97 views
Calculate torque required to rotate and hold a platform
I wish to rotate a rectangular platform about its length. It is attached to a shaft that runs through the length of the platform at width/2. How can I compute the torque of the motor required to ...
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513 views
How can I measure the torque a servo motor is applying very precisely?
Is there any cheap way to measure how hard a servo is turning?
I am looking to measure changes of about 0.1 oz-in.
What are the common ways to measure servo torque, how much do they cost, and how ...
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851 views
Increasing Torque by either doubling servos or building a gear box
I'm looking here for suggestions.
I have a HS-805BB with Torque (Kg-cm/Oz-in): 24.7/343 @ 6.0 V to rotate a robot body up and down from one side. It seems to me that this servo is always running at ...
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73 views
Torque commands for velocity reference motor
I have a controller board for a motor, where I can read the motor current (to transform to torque), the position, the velocity and I can give a velocity command. There is not really a torque mode on ...
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389 views
How to maximize stall torque of a motor
I'm looking to use 3-phase motor without gearbox for robotics application. It will always work at near stall situation never rotating more than 360deg. I'm looking for arrangement that will produce ...
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Measuring torque of Vex gear shaft - highest accuracy for lowest price [closed]
I am seeking to collect data for my IB Physics IA (internal assessment). My question seeks to establish the relationship between speed and torque by adjusting gear ratios. (I am aware that gear ratios ...
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Transforming position to torque
first question in this forum :D
so i started creating a 2 link robotic arm in SIMULINK and made a function that builds its trajectory (cubic spline) and used it as an input for my joint.
so my input ...
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How to calculate the pull force of scissors?
i want to use a stepper motor to move a brush to a industrial scissor machine to cut material of brushes.
The stepper motor will use a worm gear box to increase torque and smooth movement. The ...
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1answer
38 views
Help with DC Gearmotor Specs
I need help understanding the specs of this RS Pro DC Geared Motor, Brushed, (RS: 238-9670). It has an operating range of 4.5-15V and a nominal voltage of 12V, so does that mean that it provides 0....
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From a linear force actuator that spans multiple links and joints to the equivalent motor torque
I am programming/using a rigid body joint-space dynamics solver for robots in which I want to implement linear force actuators between links with their equivalent torque sources that are 'spanned' by ...
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Using brushless motors for very high torque
I'm currently building an robotic arm and I want the elbow joint to be comparable to a human one
But here's the problem, electric linear actuators are too slow and have low torque, same goes with ...
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703 views
How do I choose the stepper motor torque for my robotic arm
I'm a communication engineer so my knowledge about robotics is very little.
I know the basic formula of torque T=mgL
in my project I have 2 arms & 2 motors
i used a torque calculator online ...
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2answers
4k views
Robotic arm select servo motors
Hi i´m designing a robotic arm based on this idea of the NOVABOT I only want to change its structural parts by aluminum tubes. In this design 3D model it use the servo hs-311 wish have a max torque of ...
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1answer
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cable-controlled flexion and extension
I'm new, please be gentle :-)
I'd like to control the position of a single-axis joint using one cable for flexion and another for extension.
In many of the anthropomorphic designs I've seen each of ...
