DIY Pick N Place

Table of contents

Abstract

Building a DIY pick and place machine that is good for small hobbyist projects!

Project

Building Your Own DIY Pick-and-Place Machine

In this blog we’ll explore how to build a DIY pick-and-place machine using commonly available parts and an Nvidia Jetson for the brains.

The Concept

This build borrows concepts from DIY 3D printers. However, instead of a hot end for extrusion, we’ll attach a vacuum pump end for picking up and placing parts on a PCB. The project is designed to be modular, precise, and relatively low-cost compared to commercial pick-and-place machines.

The Build

1. Axes and Motion

   • Z-Axis: The Z-axis will be driven by two motors, each paired with an M8 lead screw. This design ensures stability and precise vertical movement for picking and placing components.
   • X and Y Axes: These axes will use single motors paired with GT2 tracks and pulleys. This setup is reliable and widely used in the 3D printing world for smooth, controlled motion.

2. Part Handling
   The vacuum pump end replaces the traditional hot end. It will pick up components via suction and release them accurately onto the PCB.

3. Motor Control

   • Z-Axis Motors: Controlled by the TMC5272-EVAL-KIT, which offers smooth and precise movement.
   • X and Y Axes: Driven by the Infineon BTN8982TA motor drivers, ensuring efficient and reliable operation.

4. Brains and Vision
   The machine will be powered by an Nvidia Jetson Nano, connected to a Pi Camera. The Jetson’s AI capabilities will handle:

   • Object Recognition and Detection: Identifying components to pick.
   • Alignment: Ensuring parts are placed accurately on the PCB.

Why Build This?

Building your own pick-and-place machine allows you to customize the machine to your needs, learn about robotics and AI, and save money compared to commercial options. Whether you’re a hobbyist or a professional looking for a DIY solution, this project will challenge your engineering skills and bring automation into your workshop.

Stay tuned, and happy making!

Project Genesis: Modifying the Green Mamba v2.0

Every great project starts with a solid foundation, and my DIY Pick and Place Machine is no exception. I began by repurposing the Green Mamba v2.0 DIY 3D Printer design as the structural blueprint for my machine. This versatile base provides an excellent starting point for creating a custom pick and place system.

Structural Components: 3D Printed Aluminum Extrusion Mounts

The frame came together through careful modification of the original Green Mamba design, with a focus on 3D printing mounts for 2020 aluminum extrusion. These precision-printed components allow for a robust and customizable frame that can be precisely adjusted to meet the specific requirements of a pick and place machine.

Axis Configuration

The machine's frame is built around three primary axes:

• Y-axis: 
  • 2 Guide Rails
  • TX2 Pulley
  • 1 Nema17 Motor
• X-axis: 
  • 2 Guide Rails
  • TX2 Pulley
  • 1 Nema17 Motor
• Z-axis: 
  • 2 Guide Rails
  • 2 Lead Screws
  • 2 Nema17 Motors

Challenges and Modifications

No DIY project comes without its challenges, and this build is no exception. I encountered a critical issue with the lead screws and T-nuts that required some creative problem-solving. The 400mm lead screw worked perfectly with the T-nuts, but the 200mm lead screw I initially purchased didn't align as expected.

Adaptation Strategy

• Identified mismatched lead screw dimensions
• Explored alternative mounting solutions
• Developed custom modifications to ensure precise axis movement

Next Steps in the Build

Electronics Integration

The next phase of the project involves:

• Wiring up the electronic components
• Configuring motor connections
• Calibrating the axis movements

Motor Programming

A critical step in bringing the machine to life is programming the motors to understand and navigate the X-Y-Z planes. This involves:

• Developing precise movement algorithms
• Calibrating step sizes and movement accuracies
• Ensuring repeatable and consistent positioning

Image Recognition Development

Looking ahead, the ultimate goal is to implement image recognition capabilities:

• Designing algorithms for component identification
• Creating a machine vision system
• Developing pick and place coordination code

Hardware Setup

The current implementation uses a combination of different motor drivers to control our three axes:

• X/Y axes: TMC5272 stepper motor driver (via SPI)
• Z axis: L298N H-bridge motor driver
• Vacuum control: Infineon DC Motor Shield (to be implemented)

The wiring configuration is straightforward:

TMC5272 Connections:
- SPI1_MISO -> Arduino MISO
- SPI1_MOSI -> Arduino MOSI
- SPI1_SCK -> Arduino SCK / SDA1
- SPI1_CSN -> Arduino D10

L298N Connections:
- IN1 -> Arduino D6
- IN2 -> Arduino D7
- IN3 -> Arduino D8
- IN4 -> Arduino D9

Software Implementation

The code is structured to handle three main components: initialization, motor control, and serial command processing. Let's break down each part:

TMC5272 Configuration

The TMC5272 stepper driver is configured via SPI communication. The initialization process includes:

1. Setting up the internal reference voltage
2. Configuring the chopper parameters
3. Setting current limits for both holding and running states
4. Initializing position mode for precise movements

void initTMC5272() {
    writeTMC5272(GCONF, 0x00000004); // Enable internal reference voltage
    writeTMC5272(CHOPCONF, 0x000100C3); // Standard chopper config
    writeTMC5272(IHOLD_IRUN, 0x00071703); // Set current values
    writeTMC5272(RAMPMODE, 0); // Position mode
    writeTMC5272(XACTUAL, 0); // Reset position
}

Movement Control

The system implements three movement functions:

1. `moveX()` - Controls X-axis movement using the TMC5272
2. `moveY()` - Similar to X-axis control (to be fully implemented)
3. `moveZ()` - Controls Z-axis movement using the L298N

The X and Y axes use precise position control with the TMC5272, which handles acceleration and microstepping internally. The movement is calculated based on physical parameters:

const float mmPerStep = 0.02; // Lead screw pitch divided by steps

The Z-axis implementation uses a standard stepper sequence through the L298N driver:

void moveZ(int direction, int steps) {
    const int stepDelay = 2; // Controls movement speed
    // Implements standard 4-step sequence for bipolar stepper motor
    // ...
}

Command Interface

The current implementation includes a simple serial command interface for testing:

• 'x' - Move X axis 10mm
• 'y' - Move Y axis 10mm
• 'u' - Move Z axis up 200 steps
• 'd' - Move Z axis down 200 steps

Next Steps

The next phase will involve implementing the vacuum control system using the Infineon DC Motor Shield. This will handle the pick-and-place head's vacuum pump for component handling. Additionally, I'll be working on expanding the movement system to include:

• Proper acceleration profiles
• Home position sensing
• Component position calibration
• Integration with a computer vision system

Holiday Update

Quick note: Due to upcoming holiday travels, progress will be minimal in the following week. But don't worry - development will resume at full speed once I'm back! Sometimes we all need a break to come back with fresh ideas and renewed energy.