1st project
Hi,
I would like to make this my 1st robot arm ever build.
Can you help me with the software and the diagram of the controller board?
What potentiometers did you use? Can they be integrated on the robotic arm so there is no need of additional arm for teach-in?
Regards,
Nick
Yes…I can help
To rebuild this robotic arm,
you need to have some Icecream to get the basic material for the arm 
The Potis are standard types and are screwed to the white plastic parts with their nuts. The axles are pressed into the transparent plastic part. The handle to move the teach-in-arm is a M3-Spacer and the socket is a plastic part with is normally used to fix ballons on a stick to hold it.
The Software is simple: Its working like a servotester for four axis. That means, every poti is connected to an analog in of the controller and all servos are connected to GPIOs. The controller reads each poti, does some scaling, so that the angle of the poti equals to the angle of the axis and finally he creates the PWM output 1-2ms pulse every 20ms for all servos.
For “teach in”, the controller has to save the values for each axis 5-10 times per second. So he can replay the sequence.
Thats it.
Integrating the potis directly into the robotic arm is much more complex. You can use the potis inside the servos for that job they are still there. But you need to add an extra wire to each servo and you have to move the servo motors by hand while teaching in a sequence. And that is no good idea.
The “teach-in” systems of industrial robots use force-sensors in each axis. So the teacher can move the gripper and the controller moves the arm (cotrolling the forces to zero). So the arm follows the hand of the teacher.
move servos by hand
"Integrating the potis directly into the robotic arm is much more complex. You can use the potis inside the servos for that job they are still there. But you need to add an extra wire to each servo and you have to move the servo motors by hand while teaching in a sequence. And that is no good idea."
Why moving the servos by hand is no good idea? Due to the back currents that could be generated by the motors? Or is it due to the forcing of the servo motors when they are moved by hand?
Or are there others things that makes this a no good idea?
Regards,
Nick
moving the motor by hand
Hi Nick,
to move the motor itself by hand a little force is needed due to its permanent magnets, which create a small holding force. But inside the servo a lot of gears increase the force which you have to apply. If you move the servo by hand, you have to apply a much higher force. If you overcome the motors holding force, it starts to rotate an acts as a flywheel. So moving a servo by hand needs a high torque and its not easy to turn it to the position where you want it.
I think that the voltage which is generated by the motor is not so critical.?
( Fan control modules for engine cooling of real cars have some extra parts to clamp the voltage which is generated, when you drive at higher speeds. In that case the fan works like a windmill and creates higher voltages than normal inside the powerstage of the module.)
Greetings Stoerpeak
Training to scale up
I’ve been pondering over a similar project for a few months now and was wondering whether the techniques used in assembling and programming this would be good practice for a larger multi-jointed robotic arm? I have no interest in making an automated system, just in having a robotic arm which will mimick the positioning of the user’s control.
You made me do it!
Hey Steoerpeak!
Thank you so mutch for sharing this project and the idea with the teach in arm!
Inspired from your work i did it also with extra code for smooth movement:
https://www.robotshop.com/letsmakerobots/micro-servo-robot
Vielen Dank & merci villmool!
Can you help me with code
Hey guy!
Im working a robot arm like yours.
I write the code in arduino like that : myservo.write(map(value,0,1023,0,180)); When the potentiometer at 0 position( analog=0), the servo vibrates. After i rotate potentiometer until the value= 80, the servo is stop vibrating and moving
Can you give me some suggestion to solve the problem
Can you also me your technique to control your servo as well as showing me parts of your code
Sincerely thanks!
To Let You Now
Hoi my german neightbour i just started my first oficial posting on my 5 axis bot got motivated by PINAUT 's movie on you tube
i just found out that he got it from you i was wonderring if you shared the code with him our who original wrote it please let me now
i want to put some fethers on the right place
Source code, for a similar project
Hi, this project is great. Can you send to me the source code and diagram of the controller board? Please. I would like to do a similar project. My email is [email protected]. Thanks so much!
all step by step of mini robotic arm
can u send plz
all material of requirement and also how to connected the all meterial of our pleace
