Design of a Bed Rotation Mechanism to Facilitate In-Situ Photogrammetric Reconstruction of Printed Parts

TL;DR

This paper presents a novel bed rotation mechanism integrated into a custom FDM 3D printer platform, enabling in-situ photogrammetric reconstruction of printed parts for improved process monitoring and defect analysis.

Contribution

The authors designed and implemented a unique bed rotation mechanism that facilitates in-situ photogrammetry during printing, enhancing geometric data collection for research in polymer FDM processes.

Findings

Successful integration of bed rotation with photogrammetry system

Enhanced ability to link process parameters to geometric defects

Platform provides precise control and monitoring of printing conditions

Abstract

Additive manufacturing, or 3D printing, is a complex process that creates free-form geometric objects by sequentially placing material to construct an object, usually in a layer-by-layer process. One of the most widely used methods is Fused Deposition Modeling (FDM). FDM is used in many of the consumer-grade polymer 3D printers available today. While consumer grade machines are cheap and plentiful, they lack many of the features desired in a machine used for research purposes and are often closed-source platforms. Commercial-grade models are more expensive and are also usually closed-source platforms that do not offer flexibility for modifications often needed for research. The authors designed and fabricated a machine to be used as a test bed for research in the field of polymer FDM processes. The goal was to create a platform that tightly controls and/or monitors the FDM build parameters so that experiments can be repeated with a known accuracy. The platform offers closed loop position feedback, control of the hot end and bed temperature, and monitoring of environment temperature and humidity. Additionally, the platform is equipped with cameras and a mechanism for in-situ photogrammetry, creating a geometric record of the printing throughout the printing process. Through photogrammetry, backtracking and linking process parameters to observable geometric defects can be achieved. This paper focuses on the design of a novel mechanism for spinning the heated bed to allow for photogrammetric reconstruction of the printed part using a minimal number of cameras, as implemented on this platform.