Date of Publication :17th February 2023

Abstract: This paper discusses the Universal Rotary Module (URM), a device developed at the Technical University of Kosice, which is a main component for building a modular robotic arm capable of continuous rotation without the need to rotate back. The text highlights the advantages of the URM, such as its modular architecture, ability to create kinematic chains with varying degrees of freedom, and its potential for further development by reducing component weight. It explores the use of Fused Filament Fabrication (FFF) or Fused Deposition Modeling (FDM) as an additive manufacturing technology for creating components The text addresses the challenge of connecting FFF parts with parts manufactured using different methods, specifically focusing on creating threads in parts. It compares two methods: tapping threads and using threaded inserts. The advantages and disadvantages of each method are discussed, considering factors such as tool life, breakage risk, skill requirements, load distribution, and ease of replacement. The text presents an experiment conducted to test the thread creation methods using different materials, including PLA, PLA Tough, PETG, and Nylon CF15 Carbon. The results show that the length of the thread significantly affects the strength of the joint, and the point of failure varies depending on the material and thread type. Inserts were found to be more reliable than tapped threads, and the overall strength and reliability of the joints were prioritized over maximum strength.

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