Automated In Situ Placing of Metal Components Into 3-D Printed FFF Objects

Abstract

Screws are often used to connect 3-D printed parts to other objects. When screwing directly into printed plastic, the reliability is limited, and the connection can wear out over time. For more reliable connections, standard metal nuts are often inserted into slots designed into the object. This article presents an approach where nuts and other ferromagnetic components are integrated directly into the part while printing it. Our prototype machine is a modified Prusa-I3 fused filament fabrication printer with an electromagnetic pick and place tool. We introduce augmented slicing software, where the user can insert generic component models from a library and place them at arbitrary positions in the object. Cavities for the components and additional G-code commands for robotic placing are automatically generated and sent to the printer. A printed component tray is attached to the printbed, allowing different part configurations for each print. The pick and place unit is controlled by our OctoPrint plugin OctoPNP. Index Terms-3-D printing, fused filament fabrication (FFF), multimaterial printing, rapid prototyping, smart manufacturing. in computer science (with a minor in oceanography) in 2009, started working with 3-D printers from the University of Hamburg, in 2011, the M.Sc. degree in adaptive slicing algorithms for FFF printing from the University of Hamburg, in 2014, and the Ph.D. degree in computer science from the University of Hamburg, Hamburg, Germany, in 2020, presenting design software for the integration of electronics and sensors into 3-D printed parts. He is currently a Postdoc Research Associate with the Department of Informatics, University of Hamburg. He teaches courses in computer architecture and applied robotics. His research interest is focused on slicing and design algorithms for hybrid additive manufacturing and their application in the field of robotics.

Analysis to Support Design for Additive Manufacturing with Desktop 3D Printing

“…The insertion of hardware during the build requires pausing the process at a specific step, placing the hardware in position, and resuming the build. This technique provides the added value that the hardware is fully enclosed by the FFF component and, therefore, a good load transfer for pullout strength (Ahlers et al, 2021). This method requires taking into consideration ( 1) potential collisions of the deposition nozzle and the hardware, as well as (2) the fixing of the hardware in place, which could be by tight tolerances or by use of an adhesive, and (3) the supporting of the overhanging surfaces above the hardware and their adhesion to it (Stratasys, 2015a).…”

“…However, a nut sliding pocket adds weakness to the joint. This weakness can be overcome by inserting the nut directly into the part during printing (Ahlers et al, 2021).…”