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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14
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2answers
813 views

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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2answers
13k views

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, ...
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3answers
3k views

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 ...
6
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2answers
232 views

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-...
5
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1answer
242 views

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 ...
4
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2answers
3k views

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 ...
4
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3answers
2k views

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 ...
4
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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 ...
4
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3answers
7k views

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 ...
4
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4answers
23k 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 ...
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2answers
3k views

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 ...
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2answers
1k views

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 ...
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3answers
712 views

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,...
3
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2answers
92 views

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 ...
3
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2answers
1k 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 ...
3
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2answers
1k views

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 ...
3
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1answer
576 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 ...
3
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1answer
714 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 ...
3
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2answers
258 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 ...
3
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1answer
185 views

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 ...
3
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2answers
12k views

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 ...
3
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1answer
200 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 ...
2
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2answers
2k 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 ...
2
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1answer
193 views

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.
2
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1answer
199 views

Industrial servo motor

How to control an industrial servo motor? The specific motor dive I am looking at is a Delta adsa-a2 series AC Servo Drive. I know that we can connect the motor driver to the software that the ...
2
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1answer
1k views

How do I control a servo using a beaglebone black running ubuntu

I have a BeagleBoneBlack and would like to use it to control a servo for my robot. I'm mostly programming in ros and as such am looking preferably for a c++ solution. Is there an easy way of ...
2
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3answers
615 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 ...
2
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1answer
65 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 ...
2
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1answer
249 views

How do I achieve this? Grid of dowels powered by piston-like movement

I am completely new to this site and robotics, but I have experience in programming, and programming microcontrollers. I would like to create a grid of "pixels", where each "pixel" is a metal or ...
2
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2answers
364 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 ...
2
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1answer
923 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 ...
2
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1answer
280 views

What is the difference between the holding torque and stall torque of a motor?

Do the terms holding torque and stall torque imply the same thing? The information on torque for these stepper motors is given as holding torque. While these servo motors have the torque given as ...
2
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1answer
367 views

Ultra Low Power servo and controller for long usage..? [closed]

So I have an idea which would require the following: 1-4 servos 1 microcontroller some way of communicating with it via smartphone (bluetooth or wifi) Ability to run for 14 days on a small power ...
2
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1answer
57 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 ...
2
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1answer
609 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: ...
2
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1answer
439 views

Connecting two servo motors to drive one shaft [closed]

I need to connect two servo motors (with internal position control) to rotate one shaft (to control its position), is that possible? and how to avoid synchronization problems? the servo motor I am ...
1
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1answer
837 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 ...
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2answers
742 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 ...
1
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1answer
467 views

Which kind of motors and how powerfull should they be for a robotic arm

I am building a robotic arm with these specifications: 1 meter long approx. 1kg weight it is made of 4 motors. (2 at the base. One for rotating the whole arm left and right and another one for ...
1
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2answers
81 views

Powering 6 servomotors requiring 6V and 2A each

The title pretty much says it all. I'm on a team that is currently building a robotic arm for the capstone project of my engineering degree, our design is similar to the Dobot (5 degrees of freedom). ...
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3answers
95 views

I wanna make a raspberry pi car using an RC car. I would like to know if the servo multiplexer is necessary?

So I'm working on a project and it involves making a raspberry pi car, be it from scratch or with the help of can rc car. I chose the latter. Now the problem is I don't really have servo multiplexers ...
1
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1answer
750 views

How should I power my servo motor with the Adafruit PCA9685 chip?

So I have an Adafruit pca9685 controlling an HSB-9380TH servo and a MG-996R servo. I recently began learning about building robot so I apologize if these questions seem dumb. I literally spent a days ...
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1answer
41 views

Kollmorgen S300 drive oscillation

Robotics! We've got a rotation device controlled with Kollmorgen S300 servodrive. The official support is silent as Jesus, so I've decided to ask here instead. When it is given a task to set into a ...
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1answer
887 views

Why are some motor shafts stiff while others spin freely when not powered?

Most servos and steppers I've worked with are able to spin manually when no power is applied, but I've come across a couple which are stuck in their position. I'm not sure if they are just very ...
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2answers
865 views

How to calculate battery size for servo motors?

I am making a robotic device with the following servo motors. How do I go about calculating the battery capacity? It is supposed to run for 10 minutes. I am bit confused as to use the no-load current ...
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1answer
81 views

How to power this servomotor?

I would like to use and test this type of servo motor, significantly stronger than the ones I've been using previously. However the datasheets seem to be limited and I can't exactly tell how to use ...
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1answer
182 views

Granite devices IONI servo drive

The IONI drive can accept a new setpoint using an analog input. How many bits is the ADC on the IONI drive? Is it 12, or 16 bit?
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2answers
236 views

Multiple limbs on small robots

Note: I'm a firmware developer experienced with sensors and networks, but not much with motors. I am trying to build a small hobby robot, like a cat-sized spider. I am thinking of using servo motors ...
1
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1answer
38 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 ...
1
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1answer
62 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 ...