An Innovative Method of Representing the Double Orthogonal Projection of a Line

This study presents the design and fabrication of a parametric physical model using additive manufacturing to visualize the double orthogonal projection of a line, enhancing engineering education through tangible geometric representation. The model consists of two articulated plates representing the principal projection planes and flexible cylindrical elements depicting a spatial line and its projections. Designed in SolidEdge, all parts were fabricated with FDM technology using a Creality Ender 3 printer and PLA filament. The plates include three articulation points enabling simulation of perpendicular and aligned positions. Flexible cylinders inserted into aligned holes create a kinematic mechanism that demonstrates the transformation from 3D line to 2D projections. A spotlight enhances spatial interpretation by marking projection points. Process parameters: layer height 0.2 mm, nozzle 0.4 mm, temperature 190–210°C, and speed 50–60 mm/s, ensured dimensional accuracy and a ±0.1 mm tolerance. The model proved stable, repeatable, and effective as a dynamic teaching tool in descriptive geometry and STEM (Science, Technology, Engineering, and Mathematics) education.