Mobile 3D Printer

Summary

Associated with: University of Arkansas.

Role: Research Assistant & Student in Electrical Engineering (Bachelor of Science).

Where: Fayetteville, Arkansas.

When: 2016 - 2018.

Objective: Develop a mobile 3D printing robot for enabling multi-robot cooperative 3D printing.

Contribution: I've developed all hardware elements: circuit boards, mechanical components, firmware, and outer enclosure. The mobile 3D printing robot is capable of traveling freely on a shared cartesian coordinate system.

Results:

• Successfully built two working prototypes.

• Filed 1 patent and published 1 paper.

Project Description

Cooperative 3D printing is an emerging technology that aims to provide scalability to 3D printing by enabling several printhead-carrying mobile robots to cooperate on a single printing job and to integrate pre-manufactured components during the printing process. At the core of the cooperative 3D printing platform is a mobile robot that can carry different printhead or a gripper.

How It Works

The mobile printer consists of three components: a mobile platform, a 3D printing system, and a wireless communication system. The robot moves in the XY plane using omnidirectional wheels, and the printhead moves up and down along the Z-axis as it prints. A Wi-Fi internet connection is used for sending information and receiving commands from the web user interface.

At the core of cooperative 3D printing lies the chunk-based printing strategy. This strategy splits the desired part into smaller chunks, and then the chunks are assigned and scheduled to be printed by individual printing robots. See the example below:

Technical Information

The robot is controlled by the 8-bit microcontroller Atmel ATmega 2560 running at 16MHz, paired with a Raspberry Pi 3 for enabling Wi-Fi wireless communication. The firmware is an adapted version of the Marlin Firmware for 3D printers, which is an Open Source project owned and maintained by the maker community. Two major adaptations that had to be implemented in the firmware were and addition of the omnidirectional wheels control for allowing X-Y movements. And the closed-loop control using two CMOS optical sensors to keep track of the displacements in the X-Y plane.

The custom control board (see image below) is where all the peripheral components are connected. That includes the wheels control system and the FDM extrusion system for 3D printing.

Over the course of this project, I developed two main revisions of the robot. The first revision includes all the components and functionalities described above. The second, and final revision, includes a wide-angle high resolution monitoring camera at the top of the Z-axis. As well as an overall plastic enclosure, which provides improved aesthetics and protection to the internal components. The two revisions are shown in the renderings below:

Recognition

One unit of the second revision (see photo gallery below) was sent to the 3D Pioneers Challenge (3DPC), which is an international design competition for Additive Manufacturing processes and Advanced Technologies. It is the most prestigious award of its kind and is one of the most highly endowed worldwide. The annual announcement and presentation of the finalists is considered to be the innovation monitor of the industry. The 3D Pioneers Challenge (3DPC) takes place in Stuttgart, Germany. Autodesk has announced a special mention to this design and awarded an opportunity to join their highly regarded Autodesk Technology Centers Residency Program in San Francisco, California.

Photo Gallery: