🚧 WORK IN PROGRESS 🚧
Overview
After looking at various robotic arm designs, especially those used in surgery, I decided to build my own simpler version out of 3D-Printed parts and servos. Instead of learning inverse kinematics to autonomously control my arm, I decided to create a miniature arm that the real arm would mimic.
This miniature arm would have potentiometers at each joint and a button at the wrist joint to signal when to open the claw. These potentiometers would give readings based on their angle which I would be able to map onto the respective servo motors on the real arm using an Arduino Mega. This project serves as my introduction to robotic arms and controlling servos using an Arduino + PCA9685 servo module.
Materials
- Arduino Mega
- PCA9685 Servo Module
- Five 40kg Servo Motors
- One 9kg Servo Motor
- Power Supply (5-7V, 2-3A)
Power
Right off the bat, after testing my potentiometer-servo mapping code, I ran into an issue of power. Usually, with an Arduino, I would use a 6AA battery pack or my laptop to power the components but with 40kg Servos, I would need around 2-3A of current per motor when under load.
This proved to be a problem. For testing one motor, I could get away with using an iPhone Charger that was rated for 5V at ~2A but I couldn’t simply solder multiple together and attach that to the servo module because any variation of voltages would cause a potential difference and cause current to flow back into the charger.
I am trying to find a cheaper alternative than using an expensive power supply. One thing I may try is to use a buck converter for my 3S LiPo batteries that could output my desired combination of voltage and current.