Kindly Morrow
DOF Robot Arm Kit
Four axes of independent motion control, under $40. This servo-driven arm connects directly to Arduino or ESP32 and puts real pick-and-place mechanics in your hands. PWM in, physical motion out.
Each joint maps to a dedicated servo channel, giving you base rotation, shoulder, elbow, and gripper control as separate PWM outputs. Compatible with Arduino Servo.h, ESP32 LEDC, and any PCA9685 breakout for cleaner multi-servo timing. Assembly is required, which means you understand the mechanical structure before you write a single line of firmware.
Things to build with this
- Wire a potentiometer to each servo axis and record angle values to EEPROM on button press, then replay the full sequence on demand. A physical motion macro recorder with no camera or vision system required.
- Attach a TCS34725 color sensor to the gripper and sort objects by hue into labeled bins. The 4th DOF gripper channel does the grab, the base servo does the sort sweep. No conveyor belt needed.
- Route serial commands from a Python script on your laptop to the arm over USB, mapping WASD or arrow keys to individual joint PWM values in real time. You get a live teleoperation loop with about 20 lines of PySerial code.
Key Features
- 4-DOF configuration: base rotation, shoulder, elbow, and gripper as independent PWM channels
- Standard servo protocol: works with Arduino Servo.h, ESP32 LEDC, pigpio, and PCA9685 driver boards
- 5V logic compatible: no level shifting required for most common dev boards
- Dedicated gripper servo: open/close on its own channel, not shared with arm axes
- Mechanical kit format: full assembly required, acrylic or aluminum frame depending on variant
- EEPROM-friendly workflow: servo position values are integers, easy to log and replay
- 2A minimum power requirement: separate 5V rail for servos, independent from your microcontroller
Frequently Asked Questions
What power supply does the arm actually need?
A dedicated 5V supply rated at 2A minimum, separate from your microcontroller's USB or onboard rail. All four servos drawing current simultaneously will brown out a shared supply and cause erratic behavior.
Does this come with example code?
Basic sketches are typically included or linked. Treat this as a build-and-code project. You will adapt or write firmware to match your specific motion logic, servo travel limits, and control interface.
Can I use a PCA9685 PWM driver board with this?
Yes, and it is the cleaner approach. The PCA9685 handles servo timing over I2C, freeing up your microcontroller and giving you more precise multi-servo coordination than software PWM on most boards.
Can I run this from a Raspberry Pi instead of Arduino?
Yes. Any board that outputs PWM in the standard servo frequency range works. On Raspberry Pi, use the pigpio library for hardware-timed PWM. RPi.GPIO software PWM can work but may introduce jitter at the joints.
Is the frame acrylic or aluminum?
It depends on the variant. Check the product photos for your specific configuration. Aluminum holds tighter tolerances under load. Acrylic is lighter but more flex-prone at the shoulder joint under heavy cycles.
Why we stock this
Curated by Kindly Morrow. We test and vet every product before it hits the store. If we wouldn't use it in our own builds, we don't sell it.
Things to build with this
Fun projects to try once you get your hands on it.
AI-controlled robot arm that sorts your desk
Connect it to Claude, point a camera at your desk, and let it pick up pens and put them back in the holder. Gloriously unnecessary.
Line-following robot for your hallway
Tape a black line from your office to the kitchen. The robot follows it carrying your coffee mug. Will your cat attack it? Probably.
Gesture-controlled car
Strap an accelerometer to your hand and steer the robot car by tilting. Makes you feel like a Jedi. Kids will never give it back.
Security patrol bot
Program a route through your house. Add a camera. Stream to your phone. Your dog will be confused, but your house will be watched.
