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Custom robotic-arm with 5 DoF and Arduino-like microcontrollers

MeatSauceMeatSauce GreeceMember Posts: 1
edited October 2020 in Building and Techniques
Hey there,

first post and actually first ever custom build. I built a robotic arm only with LEGO Technic parts for a project at work. The model has 5 degrees of freedom:
  1. whole robot-arm rotates left and right. 
  2. The arm moves up-down
  3. The top arm tilts up-down
  4. The grip rotates freely
  5. The grip opens-closes.
Perhaps the most interesting part of the model is the grip. It attaches to a turntable and with the use of differentials I was able to rotate the whole grip without affecting the grip's open-close movement.

Regarding the electronic parts, I used extension cables which I stripped in order to connect them to the motor driver chips (Adafruit Motor Shields) and to avoid damaging the cables of the motors. The motor drivers are then connected and controlled via an ESP8266 WiFi microcontroller and so I could steer the robot from an app on my phone via MQTT commands.

Here is a view of the "electronics box":

The Adafruit Motor Shields are the 2 large blue chipsets (stacked on top of each other) on the right hand-side. Each comprises of 4 motor outputs (named M1 - M4 print on the board). Below are the breadboards for the microcontrollers and some other sensors I used.

The full robot:

The yellow box houses the electronics. The bottop platform with the 2 battery boxes (added for stability and testing while building) hosts the turntable and the XL motor that rotates the robotic arm above.

You may also find a video showing the operation here:


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