Surface Finish Improvement Using Retraction Method for Fused Deposition Modeling Printed Samples

Abstract

In additive manufacturing, retraction is a key technique for minimizing stringing, oozing, and blobs when the print head moves between model sections without extruding the filament. Proper retraction tuning is critical for improving print quality, as overly aggressive settings can cause under-extrusion, nozzle clogs, or extruder wear, while weak retraction may fail to eliminate artifacts. This study explores the effects of three retraction parameters such as z-lift, speed, and lengthon the surface roughness of 3D printed parts using an orthogonal array design. 27 samples were printed using Folgertech open-source FDM 3D printers with ABS-M30i material. Test samples were modeled using SolidWorks CAD software and printed using Repetier software to optimize quality. Surface roughness (Ra) was measured using the Mitutoyo Surftest SJ 301, and surface structures were analyzed with a Stereo Microscope. Results show that Sample 11, with a z-lift of 1 mm, speed of 20 mm/s, and retraction length of 1 mm, achieved the lowest Ra value (1.33 μm). In contrast, Sample 23, with a z-lift of 2 mm, speed of 40 mm/s, and length of 5 mm, produced the highest Ra value (5.93 μm). These findings demonstrate that surface finish quality is significantly influenced by retraction parameters. The experimental design approach effectively identifies optimal process parameter combinations with minimal trials, providing a strategy for optimizing surface finish in FDM 3D printing.