Questions tagged [servomotor]

A servomotor is a closed-loop servomechanism, typically used in industrial applications. It usually consists of a motor coupled to a sensor (e.g. encoder) for precision position feedback, typically using a low ratio gearbox or direct drive.

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What is the best way to power a large number (27) servos at 5 V?

I apologize if this question may sound a little vague. I am working on a robotics project that will contain 27 servos of various sizes and I am having trouble figuring out how they should be powered. ...
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13 votes
2 answers
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Should I switch my servo system from brushed to brushless motors?

I have a robot that uses brushed motors in its servo system. These are Maxon 3W motors, with 131:1 planetary gearboxes. The motors are controlled by a PIC microcontroller, running a 1kHz PID ...
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8 votes
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How to use Arduino for ESC control?

I am using an Arduino Uno to control an ESC for my (in progress) quadrocopter. I am currently using the servo library to control the ESC, which works great. Except.. A count of 100 is max speed, ...
Toozinger's user avatar
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2 answers
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Do servo motor specifications take into account the gear ratio inside?

I am looking at buying a servo motor for a an application that must be able to lift 4-5 lb at a rotational speed of approximately 1rpm. The servo motor listed here http://www.robotshop.com/ca/en/hitec-...
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5 votes
1 answer
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Servo horn dimensions - What is 25T?

I wonder that horns for servos are marked in some T units. Example: 25T Please help me getting out, what does it mean.
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2DOF arm with quick movement: Stepper, servo, or DC motor?

To make a two degree of freedom arm capable of speeds needed to play air hockey, how should the arm be controlled? I'm wondering about speed vs accuracy. The following image is from a project ...
Bort's user avatar
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1 answer
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Finding a light load high precision servo motor

I have a project that requires me to be able to accurately and repeatedly rotate an object 120 degrees. The object is small and lightweight (let's say several grams). The axis does not necessarily ...
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For robot wheel control : Brushless DC motor or Servo Motor?

Simply, when to use brushless dc motor and when to use Servo Motor ? what are the differences , specially when adding an encoder to the dc motor you can have the position and it will be similar to ...
RoboMan's user avatar
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2 answers
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Lifting robotic leg with only one servo

Note before I start: I have not actually put anything together yet, i'm still just planning, so any changes that require a shape change or anything like that are accepted. I'm working on making a ...
ruckus's user avatar
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3 answers
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Is a thrift store a good place to get a servo motor?

I'm trying to learn about a very basic motor, the servo motor. Can these be found a thrift stores like Goodwill in old toys? Are these "robotic" quality? What toys or other kinds of things would I ...
johnny's user avatar
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2 answers
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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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Controlling digital servos

Many websites say that analog servo motors work on 50Hz and digital servo motors work on 300Hz. My question is, does this difference apply only to the inner control loop of the servo or does the user ...
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4 votes
2 answers
3k views

Up to what force is a servo motor a reasonable choice as an actuator?

I'm working on an application where I need to apply a linear or angular force to operate a linkage mechanism, but I don't (yet) know what amount of force I will need. I anticipate that it will be less ...
JYelton's user avatar
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2 answers
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Can I control more than 18 servo motor with a Raspberry Pi

I'm trying to make an hexapod with 18 servo motors and i'm asking how to control them with a Raspberry Pi. (Never used it). I saw lot's of stuff to control 1, but 18, 20... Currently I'm working on ...
Arthur's user avatar
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Can we simulate a actuator with a very strong torque with a PID controller

I use gazebo to simulate a robot arm. To control its joints, I use PID controllers. As you might know, PID are sometimes pretty hard to tune and this is the case for a robotic arm. To avoid any tuning,...
Robin's user avatar
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Should the therotical parameters match the physical setup constraints when modeling a robot?

I'm working on modeling and simulation of robotic arm, after I obtained the mathematical model of the robot, I used that to implement some control techniques, to control the motion of the robot. The ...
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4 answers
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How Can I Measure the torque applied by a servo motor?

I believe that there must be a tool that can measure $oz-in$ of torque. I do not trust what the servo manufacturers state on their site for torque values, so I want to test them for myself. Can ...
RC Hobbyist's user avatar
3 votes
2 answers
522 views

Best way to estimate velocity of motor with encoder

I'm designing a PMSM controller with the motor has an optical encoder, so I can get position information from the motor. But how to measure the velocity of the motor. Now, my design is to calculate ...
Hyz Yuzhou's user avatar
3 votes
5 answers
35k views

How to program a continuous servo motor? (Arduino)

I need to use continuously rotating servo for a camera stabilization system. My professor bought servos that have already been modified for continuous motion--there's no stop in the gears, and the ...
user153129's user avatar
3 votes
1 answer
215 views

How to attach plate to stepper motor?

Total noob here (never touched Arduino before today), & have pretty much no hands-on technical experience (although with lack of experience, I make up in enthusiasm to learn!) Question: How do you ...
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2 answers
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Electronic Speed Control Concepts

I am a programmer who has never worked with electronics before. I am learning the concepts and hoping to build a quadcopter, with the control software entirely written by me. Motor control seems to be ...
necromancer's user avatar
3 votes
1 answer
617 views

High Res Rotary Encoders [closed]

As part of a project I need an encoder to determine the angle that this, Continuous Rotation Servo - FeeTech FS5103R, has rotated through. The resolution needs to be fairly high as I will be using it ...
M Russell's user avatar
3 votes
1 answer
1k views

Choice of a motor for robotic arm

This is my first post here, so hello all. I really hope I can learn a lot from you guys. I am trying to build a robotic arm to carry an object and put it inside of different boxes that are placed in ...
Almog Boanos's user avatar
3 votes
1 answer
598 views

How does the "rated torque" for a gear relate to the maximum torque?

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
arennuit's user avatar
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3 votes
1 answer
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Stated power for a motor does not equal nominal voltage x current?

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
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3 votes
2 answers
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Choosing DC motor: max needed torque vs nominal torque

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
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2 votes
1 answer
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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 ...
HelloGoodbye's user avatar
2 votes
2 answers
3k views

Steering using different speeds in DC motors or using a servo?

I am trying to assess the pros and cons of steering a robot car using different speeds of 2 or more DC motors versus using a servo and a steering mechanism? From your experience which is better in ...
Kalaji's user avatar
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2 votes
1 answer
1k views

Measure weight of an object using a servo

Assuming a quality industrial servo, would it possible to calculate the weight/resistance of a load? Maybe by comparing current draw in a holding position, or by the time it takes to lift/lower an ...
skibulk's user avatar
  • 125
2 votes
2 answers
361 views

Servo Starts Oscillating Under Disturbance

I'm using MG996R servos to control a 6-axis desktop robot arm. When no disturbance (like a gentle push to the robot), the servos are fine and can hold their places. But under a gentle disturbance, ...
Ruotong Jia's user avatar
2 votes
2 answers
224 views

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?
HollyPolly's user avatar
2 votes
1 answer
158 views

How to control the position of a load shared between two (servo)motors?

I want to position-control an axis combining the action of two DC servomotors - one of them alone is not powerful enough; I had those available and preferred not to buy a new one. I have not the ...
temporary_pigeon's user avatar
2 votes
1 answer
147 views

Encoder attached to output of gearbox of stepper motor

I'm building a SCARA robot controlled with stepper motors and want to use an encoder to close the loop. The main reason for this is I am using an experimental gearbox with nonlinearities and zero ...
henradrie's user avatar
2 votes
1 answer
2k views

18 MG996R servo motors control and power

I am currently working an a personal hexapod robot project. I am building it using 18 MG996R 4.8 to 7.2 V servo motors. I would like to use a Raspberry Pi 3 B+ to control it. I purchased a 7.4&...
RayB's user avatar
  • 21
2 votes
1 answer
7k views

Calculating screw breakaway torque

I'm trying to use motor-sizing tool developed by oriental motor to choose good servo motor for my cnc The tool requires breakaway torque of my screw as input, I searched online but I got people ...
Ammar Hussein's user avatar
2 votes
2 answers
438 views

Why does it require more force to turn a servo if it is electronically connected to another servo?

I have two servo motors that I rigged up to use as a telescope remote focuser. The idea is to turn one servo by hand and use the power generated to turn the other, which is geared to a telescope ...
LiberaVeritas's user avatar
2 votes
3 answers
834 views

Sun tracking with +/- 0.1degree accuracy?

For a school project I am looking to track the sun with +/- 0.1 degree accuracy for use with a parabolic dish reflector. Say we need a final output torque of about 20Nm, what kind of gearing/motors ...
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2 votes
1 answer
141 views

I've got a few servo motor questions

How can I measure the amount of voltage I'm giving a servo motor? How can I give a servo motor the correct amount of power it needs to run at it's full potential? Say I had this motor: ANNIMOS 60KG ...
Anonymous's user avatar
2 votes
1 answer
233 views

Is it possible to calculate the gear reduction based on datasheet of SG90?

is it possible to calculate gear reduction based on the datasheet of SG90 servo motor? Because I wanted to do some modeling in Simulink and RC servo ask for gear reduction, but I can't find any ...
Geddoe's user avatar
  • 21
2 votes
1 answer
1k views

Torque control and monitoring of servo

I am trying to control the servo motor operation by torque control by interfacing the sensor to an avr , which will continuously monitor the torque value from the sensor and control the torque ...
Soumya's user avatar
  • 21
2 votes
1 answer
209 views

Why are the IRB 1410's servos running even when the joints are not moving?

I was jogging the ABB IRB1410 and I noticed that the servo motors are humming even when the joints are not moving. The motor cuts off only when the guard switch in the flex pendant is released. What ...
atree's user avatar
  • 149
2 votes
0 answers
21 views

Coordinating long-running actions with independent threads [closed]

Basically, some things have real-world durations that need to be accommodated. For example, moving a servo arm 180° will take a significant number of milliseconds. What is the best practice for ...
RoUS's user avatar
  • 121
2 votes
0 answers
76 views

Floppy fish mechanism design

I've bought a floppy fish toy (crab version) for my kid. The toy looks like: Unfortunately, the toy mechanism inside jams when grabbed and the battery lasts for a short time: I tried to do my own ...
Kuba's user avatar
  • 21
2 votes
1 answer
69 views

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 ...
user2081488's user avatar
2 votes
1 answer
834 views

Driving Rhino DC servo motor using Arduino through commands sending from MATLAB

I have a servo motor (http://robokits.download/documentation/RMCS220x_DCServo_Driver.pdf). I wrote a code in Arduino to rotate it in some defined angles and position. Code is given below: ...
Naseeb Gill's user avatar
2 votes
3 answers
503 views

Selecting a gear reduction: torque vs speed

I have just sized the DC motors I want to use (corresponding to my robot and its intended applications - my figures include a 50% uncertainty factor to account for friction in reducers and other ...
arennuit's user avatar
  • 609
1 vote
2 answers
275 views

How to avoid oscillations caused by backlash in position control?

I am working with a ball screw mechanism driven by a brushless dc motor with an encoder mounted on the load side. We are using a PID position controller with tuning settings by optimization however ...
controlsHeaven's user avatar
1 vote
2 answers
807 views

Building industrial-like robotic arm

I would like to build a 70cm articulated robotic arm (not a scara one) that can lift between 10kg and 15kg (10kg would be awesome already, this payload includes the weight of the arm+gripper) and ...
LiohAu's user avatar
  • 161
1 vote
1 answer
496 views

How to calculate the right needed Power?

Me and my team are building a robot and I need to calculate the Power of the motors. Through my research I found that I must know the needed torque for every motor and then convert it to electrical ...
MichaelDuth's user avatar
1 vote
2 answers
2k views

Which motors are used in boston spot robot

I want to know which motors or smart servos are used in boston dynamics spot robot. Where can i read its spicification and is it possible to buy the motor?
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