Picture of Easy and Simple Arduino Robot Arm
robot arm 1.png
Hello fellow iblers!

This is to serve as a small guide to replicating my most recent project; an Arduino based robotic arm.

First off I would like to acknowledge the help of Instructables user steveastrouk for getting me started on the programming, and my good friend Sean Ulrich for spending 6 hours debugging this thing with me.

Do to a technology failure I don't have any of the progress pictures otherwise this would be a full ible, I apologize for the inconvenience and hope that I supply enough information here to help get you on your way. So let's get started!

Here is a list of parts I used:

1x Arduino Uno
4x Large Servo
1x Medium Servo
1x Robotic Claw
1x Small Breadboard
4x Potentiometer
2x Toggle Switch
1x Battery Case for 4 D-cells (6v)
1x Arduino Battery Clip
~2 square feet of birch plywood 1/8' thickness
1/2 inch diameter basswood dowels
2x 1'x1'x3' blocks of basswood
~2.5 lbs of lead beads
5x servo wire extensions
Some decent compression spring to keep the load off of the servos when fully extended
Some kind of enclosure (I used tin boxes I bought at Michael's)

And an absolute buttload of hot glue.

The Code is attached as a txt file.

Please take not of the footnotes on the pictures for more details.

EDIT: Here is a video-

robot arm.txt970 bytes
bakhosrahme3 months ago
Can you use stepper motors instead?
bakhosrahme3 months ago
Can you use stepper motors instead?
andrea_senz4 months ago

Hi Sir, i can't understand some things...

In the picture you posted there is 4 potenziometer while in the diagram circuit you use 5 potenziometer and also in source code you declaire 5 potenziometer!

Also , in the diagram circuit you attach the signal of the servos in digital pin 1,2,3,4 and 5 while in the code source you attach the servo in 3,5,6,9,12

Can you make me understood, please?

thank you

yoppo4 months ago

hello, excuse me but what are the specs of the servos? are they continuous rotation?

martzsam (author)  yoppo4 months ago
They are just size large 180 degree servos. NOT continuous.
thecrazylol5 months ago

did the same setup, but only 3 servos and 3 potentiometers. everything else is the same. deleted the 4th and 5th servo in the code and also deleted the 4th and 5th potentiometer. I have an external power source of 5v. the servos are working, but don't respond as i turn the potentiometer. what did go wrong?

martzsam (author)  thecrazylol5 months ago
If you post a picture of your setup i will be able to help you better.

Maybe you didn't attach the wires to the approriate pins?

servo1 is attached to pin3, servo2 to pin5, servo3 to pin6. potentiometer1 to analog pin A1, potentiometer2 to analog pin A2 and potentiometer3 to analog pin A3. like it is described in the code, but then with two less.

martzsam (author)  thecrazylol5 months ago

It looks like you are sharing a power source between the potentiometers and the servos. I your source doesn't have the ability to supply enough amps your pots could starve out.

Here is a quick checklist of things to try.

1. Run the servos on a separate source from the arduino board.

2. Run the pots on the 5v out port from the arduino and ground properly.

3. Make sure the arduino is receiving 9v and

4. Make sure your servos are getting the optimal amount of voltage for them to function. (5v may be a bit low.)

5. Double check the code to make sure all your pins are correct.

srishti b8 months ago

cn i hv its circuit diagram

martzsam (author)  srishti b8 months ago
A diagram of it's wiring is already available in the instructable :)
spyrossan11 months ago

which arduino could I use for it??

Arduino Uno R3 Microcontroller - Atmel ATmega328 or Arduino Uno - Atmel Atmega 328-PU

martzsam (author)  spyrossan10 months ago
I used the Arduino Uno R3.
ovydyu1 year ago

Hi,can you please tell me the specifications for the servomotors.I have found many large servos with different specifications and i don't know exactly what to buy.

It will be of big help if you putt the links from where you buy it. Thank you.

rosman11 year ago

about the wrist servo, this is just a idea, but maybe it is because there is something wrong with the servo. does it work by itself?? Thanks

aaggarwal71 year ago
Can u mail me the PDF on
Thank you very much!!!
martzsam (author)  aaggarwal71 year ago

this is a link that should take you directly to the PDF.
msafwan1 year ago
Sir can i make it work wirelessly
jlim341 year ago
Hey sir, I am doing similar project, is there any way make the robotic arm work like this when we do a colour sorting project? means that the robot will grab the object and run in a predesigned path and allocated it into different colour station along the path
martzsam (author)  jlim341 year ago
Hi! This is a manually controlled robot, meaning their is no autonomous function. A robot that performs a set of predefined tasks would require a bit more programming effort and a different set of hardware. Although it wouldn't be too hard to adapt this robot for your purposes. Do you have access to some kind of color sensor?

Hey sir, yes I have, I have bought Arduino servos all those plus the TSC 3200D colour sensor. here is the image below... Can we contact at email? or facebook? here is my fb.

Here is the picture on some of the material

aminerobo1 year ago
Hey sir, I am want similar project , but with Remote Control
anyone want to help
thank you
keena981 year ago
how exactly did you construct the hand?
yurekang1 year ago
what i can't download the pdf?
martzsam (author)  yurekang1 year ago
Only pro users can download the PDF.
sir im going to do the same project.please can i know the specifications of the servo motors.and can u please give the comments for the code lines
DeVid3aN1 year ago
hey what OHM potentiometers? probably a dumb question but I'm going to try construct something like this and noticed there was a massive range of them. im a newbie to this kind of thing

martzsam (author)  DeVid3aN1 year ago
10k. They are pretty much the best for this project. Don't limit yourself to knobs though! These come in all kinds like sliders too.
henryg461 year ago
Nice job

I'm going to attempt to make something similar and had a few questions.

The Pot controlling the servo's at the shoulder. Are you using a splitter wire and controlling both servo's with just one potentiometer?
Also are you using standard servo's or some type of high torque servo?
Lastly are you running batteries simply for portability. Is that why you aren't powering everything off the arduino connected from an AC power source.

thanks in advance
martzsam (author)  henryg461 year ago
Yes, no, and yes. The servos at the shoulder are connected just like the others excepting a shared signal wire. (The yellow one.) And I used a battery pack specifically for portability, the robot was built for a contest. A wall wart could easily be used to substitute. The servos I used are just regular servos I bought online on spark fun.
halflings2 years ago
Excellent job ! You really nailed it :-)
martzsam (author)  halflings2 years ago
M.C. Langer2 years ago
Love this project! :-)
martzsam (author)  M.C. Langer2 years ago
lean042 years ago
you should use levers instead of potetiometers so it looks like a crane =)
good work!
phaggood2 years ago
What's your source for the claw?
martzsam (author)  phaggood2 years ago
I actually won the claw as a prize from a contest on this website, but you can buy a similar claw on sparkfun.
Thanks ! Glad to know you think I helped ;-)