How to Build the Easiest Robotic Arm at Home

In this guide, I’ll explain how to connect servo motors, convert potentiometer input into servo movement, operate several servos simultaneously, and share my own robotic arm design along with ideas for alternative building methods and improvements.

Later, I rebuilt "Wall-A" using wooden craft sticks and hot glue. I also added a fourth servo motor that works as a gripper and programmed the arm to perform a button-triggered pick-and-place action.

Supplies

Arduino board (any compatible model)

3 Micro Servo Motors

3 Potentiometers (10kΩ)

External 5V Power Supply (recommended because the servos require more current than the Arduino can safely provide)

Jumper Wires

Breadboard (optional but highly recommended)

Lightweight construction materials such as cardboard, craft sticks, tape, zip ties, or similar items

Step 1: Wiring the Components

The three servos provide movement for different sections of the robotic arm.

The first servo controls the base rotation, allowing left and right movement.

The second servo controls the main arm section, moving it up and down.

The third servo controls the forearm section, providing additional vertical movement.

Each potentiometer is assigned to a specific servo. Connect the center pin of each potentiometer to an analog input on the Arduino. For example, A0 can control the base servo, A1 the arm servo, and A2 the forearm servo.

The remaining two potentiometer terminals should be connected to 5V and GND.

For each servo motor, connect the signal wire (usually yellow or orange) to a PWM-capable digital pin on the Arduino. In this project, pins D9, D10, and D11 are used.

Connect the red wire to 5V and the black or brown wire to GND.

At this stage, it is highly recommended to power the servos using an external 5V supply rather than relying solely on the Arduino.

Once everything is connected, upload the provided code. Turning a potentiometer should now directly control the corresponding servo motor. You can also open the Serial Monitor to view the angle values being sent to each servo.

Step 2: Building the Base

Choose a sturdy and stable platform to mount the first servo. Suitable options include a wooden board, tabletop, cutting board, or any solid surface.

Secure a servo horn to the base material using screws, glue, tape, or another fastening method. Set the base servo to its center position of 90 degrees before attaching it. The servo will then be able to rotate approximately 90 degrees in either direction from its starting position.

For my build, I used a heavy wooden block as the foundation and fastened the servo horn with screws. Although this worked well, it took considerable effort. Hot glue would likely provide a much easier solution while achieving similar results.

Step 3: Constructing the Main Arm

Set the arm servo to its 0-degree position.

Attach your chosen arm material—such as cardboard strips, wooden sticks, metal rods, or similar lightweight supports—to a servo horn and connect it to the servo.

I happened to use metal parts left over from an RC vehicle project, but any material that is strong enough to support the remaining arm sections should work.

Next, attach the arm servo to the base servo. Position it so that the arm can lift upward freely without colliding with the base structure.

I temporarily joined the two servos using double-sided tape. While convenient, it was unable to support the arm’s weight for long periods. For a stronger and more permanent solution, hot glue or super glue is recommended.

Step 4: Constructing the Forearm

Move the forearm servo to its 90-degree position.

Attach another lightweight arm section to a servo horn and connect it to the servo as shown in the original build.

Since the forearm only needs to support itself, lighter materials are generally sufficient unless you plan to install a gripper or additional tools at the end.

Mount the forearm servo to the tip of the main arm section.

For this prototype, I used double-sided tape to secure both the servo body and the servo horn. However, the connection was temporary and could not reliably support the servo's weight for extended use.

For long-term durability, stronger adhesives such as hot glue or super glue are highly recommended.

Step 5: Experiment and Improve

Your robotic arm is now ready to use.

Try experimenting with new features and modifications to make it more capable and interesting.

Some future upgrades I have considered include:

Creating a programmable mode where users manually move the arm with potentiometers, record a sequence, and have the robot replay the motions automatically.

Adding several predefined movement routines that can be activated by pressing buttons.

Installing capacitors to help smooth servo motion and reduce unwanted jitter.

Most importantly, keep experimenting and enjoy building!