The AM Dowel – A Novel Insert for the Integration of Threads into Additive Manufactured Polymer Components

Abstract

Within this paper, an insert for the integration of female threads into additive manufactured (AM) polymer parts is presented. The fastener consists of three components: a metallic threaded insert, an AM optimized female cutout and an AM polymer clip. By exploiting AM's geometrical complexity, the design has several advantages compared to conventional solutions including a fast and reversible assembly process without the use of specialized tools. The insert's pull-out strength was evaluated on a tensile testing machine. The results showed that the fastener can withstand loads of up to 5600 N (for 3/8{\textacutedbl}-16 UNC thread size). Within a case study, the insert is integrated into a Selective Laser Sintered (SLS) top handle for videography applications. The fasteners were fully functional and endured extensive real-life operation. The results of the experimental tests and case study demonstrate that the novel insert design creates new potentials for AM products, as additional applications for polymer-based AM processes are enabled. Customization and flexibility are established within the hardware part as designers can choose their required insert from ready-to-use building blocks {\&} even change it throughout use as the connection is standardized and reversible.