AmbiDexter: Dual Arm SCARA Mobile Manipulator
A custom dual-arm SCARA mobile manipulator robot built on an omnidirectional Mecanum wheel base — featuring two independently controlled SCARA arms with stepper linear actuators, adaptable grippers, and 3–5 hours of battery life.
Overview
AmbiDexter is a custom-built dual-arm SCARA (Selective Compliance Articulated Robot Arm) mobile manipulator. Standing 1080mm tall on a 470×400mm omnidirectional Mecanum wheel base, the robot features two independently controlled arms each with a 500mm stepper linear actuator, heavy-duty servo shoulder and elbow joints, and adaptable gripper mounts — all powered by four 12V sealed lead acid batteries for 3–5 hours of continuous operation.
Specifications
Dimensions: 470 × 400 × 1080 mm (1.5 × 1.3 × 3.5 ft)
Base
- 4× 80rpm DC worm gear motors
- 4× 100mm omnidirectional Mecanum wheels — full holonomic movement (forward, backward, strafe, rotate)
- 2× Dual DC high-current PWM motor controllers
- 1× Arduino UNO microcontroller (KEYESTUDIO Super UNO)
Arms (×2 — Left & Right)
- 1× MKS Gen 1.4 Arduino-compatible microcontroller per arm
- 1× 500mm stroke NEMA 17 stepper motor linear actuator (with limit switch homing)
- 2× Heavy-duty large servo motors (shoulder + elbow)
- 2× Standard servo motors (grippers)
- Adaptable gripper mounting plate — quickly swappable with custom gripper designs
Power
- 4× 12V 7Ah sealed lead acid batteries — 3–5 hour runtime
- 12V → 5V step-down converter (servo power)
- 12V → 19.5V step-up converter (main computer)
- LED battery voltage monitor (voltage or % display)
- Big red emergency on/off switch — twist to on, push to off
Head
- Interchangeable head mount (standard 1/4-20 camera bolt compatible)
- 2× ELP Industrial Webcams for computer vision
- Compatible with 7” HDMI monitor, LIDAR, audio, and other sensor accessories
Software & Control
The robot uses the open-source Megamark Arduino Library — a speed-controlled, synchronized wrapper for servos, DC motor controllers, stepper motors, and serial communication across Arduino UNO and Mega boards. Three separate Arduino controllers handle the wheel base and each arm independently.
⚠️ The robot does not include software-level self-collision prevention — avoid commanding the arms into configurations that would cause them to crash into each other or the base.
Gallery
