Summary of DIY ROBOTIC ACTUATOR BUILT FOR WALKING ROBOTS
Aaed Musa developed a high-performance quasi-direct drive actuator to overcome the limitations of off-the-shelf servos for walking robots. This custom build features a brushless DC motor paired with a 9:1 planetary gear reduction using 3D printed components, driven by an ODrive S1 controller with encoder feedback. Weighing 935 grams and costing nearly $250, the actuator delivers over 16 Nm of holding torque, proving its capability through heavy-duty demonstrations.
Parts used in the DIY Robotic Actuator:
- Brushless DC motor
- Planetary gear reduction (9:1 ratio)
- 3D printed parts
- ODrive S1 motor controller
- Encoder feedback system
[Aaed Musa] has built a variety of robots over the years, but found off-the-shelf servos to be underwhelming for his work. Thus, he set out to build a better actuator to support his goals of building a high-performance walking bot in future.
[Aaed] decided to try and build a quasi-direct drive actuator, similar to those used in MIT’s agile mini Cheetah robot. It consists of a powerful brushless DC motor driving a 9:1 planetary gear reduction built with 3D printed parts, which provides high torque output. It’s designed to be run with an ODrive S1 motor controller with encoder feedback for precise control.
The actuator weighs in at a total of 935 grams. It’s not cheap, with the bill of materials totaling just under $250. For your money, though, you get a responsive robotic actuator with a hefty holding torque of over 16 Nm, which [Aaed] demonstrates by having the actuator shake around some dumbells on a long lever arm.
Walking robots have exploded in popularity ever since Spot hit the scene. We’ve seen everything from complex builds to super-simple single-servo designs.
Source: DIY ROBOTIC ACTUATOR BUILT FOR WALKING ROBOTS
- Why did Aaed Musa build this actuator?
He built it because off-the-shelf servos were underwhelming for his goal of creating a high-performance walking bot. - What type of actuator design was chosen?
A quasi-direct drive actuator similar to those used in MIT's agile mini Cheetah robot was selected. - How much does the actuator weigh?
The total weight of the actuator is 935 grams. - What is the cost of the bill of materials?
The bill of materials totals just under $250. - What is the holding torque output of the device?
The actuator provides a hefty holding torque of over 16 Nm. - Which motor controller is used for precise control?
An ODrive S1 motor controller with encoder feedback is used for precise control. - How was the actuator's power demonstrated?
Aaed demonstrated the power by having the actuator shake dumbbells on a long lever arm.
