Final project: PLOT BOT V0.1

presentation

1. Concept

Mecanum wheeled pen plotter with infinite* plotting area: This project is a mobile pen plotter that uses Mecanum wheels and can draw on surfaces much larger than its own size (*currently limited by wires though). The robot uses Pi Pico to receive G-code via serial, parse it directly, and control stepper motors on 4 Mecanum wheels and a Z-axis servo, with end-stop for zeroing.

2. Potential use cases

This machine can create large-scale drawings without being constrained by the physical size of the device. Possible applications include drawing large calligraphy, dot art and even drawing Nazca Lines.

3. Background

The idea started from a simple curiosity: could a machine print or draw things bigger than itself? Traditional 3D printers are limited by their fixed frames. This machine moves freely in X and Y directions using omni-wheels, and could later add a Z-axis arm for height. In the future, it might even be able to climb onto its own printed objects and keep building—making truly large-scale 3D printing possible.

4. Technical overview

The robot interprets G-code and moves using four Mecanum wheels. A microcontroller (Raspberry Pi Pico) directly runs motor control logic without standard firmware, allowing custom handling of omni-directional movement. Basic Z-axis control is handled by a servo.

For more details, please also see:

Next spiral

A. Improvements as a pen plotter

Add absolute tracking for position correction
Enable wireless control and battery power

B. Learn and incorporate 3D printing technologies

Improve Z-axis design for 3D printing
Learn 3D printing through building filament recycling machine
Learn 3D printing firmware

C. System integration: PRINT BOT V1.0

Integrate filament feeding system and extruder

next spral *Sorry, this was written by me, not this machine.

Thank you!

Master Tamiya-san for your consistent and thoughtful guidance, often late into the night, every week!
Tokuyama-san and Ito-san for making the learning process fun, inspiring, and even delicious!
Issac for checking and reviewing our work!
Asia Regional Review team, including Rico-san and Saheen, for your always valuable feedback, it’s kept me motivated to keep improving!
Neil for the class and the network!

As Neil said, class isn't over, it now beggins.