3D printing robotic arm

1. Introduction to robotic arm

In terms of mechanical production, aluminum profiles, 3D printing, timing belts and stepper motors are used, which is a low-cost production solution. As for the controller, it uses esp32s3 chip with WiFi and Bluetooth function. Can output 100KHZ pulses, supports joint motion and linear motion commands, 8 outputs of 150mA, 8 inputs of 6~36V, with optocoupler isolation. In terms of programming, blockly visual programming is used, and programming can be completed using a mobile phone or tablet.

2. Production process

1. Mechanical part

First use FreeCAD software to draw the 3D model drawing. FreeCAD is an open source 3D design software that can be used for free, facilitates secondary development, and supports motion simulation and simple finite element simulation. I used it to design my robotic arm. The first three joints adopt a dual-motor structure, which means that one joint has two motors. This balanced design not only improves the load capacity, but also improves accuracy and stability. This robotic arm now has a load capacity of 2.4kg, a repeatable positioning accuracy of 0.5mm, and an arm length of 765mm.

2.Controller part

2.1 Main controller

The main controller uses ESP32-S3 chip, which has WiFi Bluetooth function, dual core, 240Mhz frequency, and 45 programmable GPIOs. The performance can meet the requirements of the robot arm operation algorithm, and 6 pulse control interfaces are designed to control the 6-axis robot arm. 8 inputs and 8 outputs, with photoelectric coupling to protect the circuit and facilitate external solenoid valves.

2.2 Motor drive part

The stepper motor driver uses the TB67S109AFTG chip and supports a maximum current of 4A. The control chip uses ESP32-C3, which supports pulse control and CAN communication control. The magnetic encoder uses MT6816CT-ACD, a 14-bit single-turn absolute encoder with a maximum accuracy of 0.02°.

2.3 Software part

The main control board program is based on the open source micropython, which enables the development of microcontroller programs using python language. Driver board programming is a C language program written based on the ESP-IDF library. The mobile phone control software is written based on the open source blockly and bipes.

3. Instructions for use

https://www.bilibili.com/video/BV13e4y1d73w