Design and Fabrication of PLA and PETG Knuckle Joints Using FDM 3D Printing Technology: A Comparative Study

Moiz P Shaikh1

1Lecturer of Department of Mechanical, Santosh N Darade Polytechnic, Yeola

Abstract - Additive Manufacturing (AM), commonly known as 3D printing, has emerged as a revolutionary manufacturing technique capable of producing complex geometries with reduced material waste and shorter production times. Among various additive manufacturing methods, Fused Deposition Modeling (FDM) is one of the most widely adopted technologies due to its affordability, ease of operation, and compatibility with thermoplastic materials. The present study focuses on the design and fabrication of a knuckle joint using FDM technology and investigates the suitability of two widely used thermoplastic materials, namely Polylactic Acid (PLA) and Polyethylene Terephthalate Glycol (PETG). A standard knuckle joint assembly consisting of a single eye, double eye, and pin was modeled using CAD software and fabricated using a Creality FDM 3D printer. The fabricated specimens were evaluated based on print quality, dimensional accuracy, surface finish, manufacturability, and material characteristics. Comparative analysis indicates that PLA provides superior dimensional accuracy and ease of printing, whereas PETG exhibits better toughness, layer adhesion, and durability. The study demonstrates the feasibility of utilizing FDM-manufactured polymer knuckle joints for educational, prototyping, and lightweight engineering applications.

Keywords: Additive Manufacturing, FDM, PLA, PETG, Knuckle Joint, 3D Printing, Rapid Prototyping.