Researcher(s)
- Connor Fidgeon, Mechanical Engineering, University of Delaware
Faculty Mentor(s)
- Tyler Van Buren, Mechanical Engineering, University of Delaware
Abstract
Fused filament fabrication (FFF) offers an accessible and cost-effective method for rapidly producing components for underwater robotic systems, but microscopic voids, incomplete interlayer bonding, and aligned seam pathways can allow water to penetrate printed parts. This research investigates how parameters available within PrusaSlicer can be optimized to produce repeatably watertight PETG components without coatings or other post-processing techniques. Closed cylindrical specimens were printed on an Original Prusa MK4S while varying nozzle temperature, print speed, extrusion multiplier, layer height, perimeter count, seam position, and other slicer-controlled settings. Watertight performance was evaluated by measuring specimen mass before and after submersion in a pressure chamber at 60 psi for one hour, approximately equivalent to a water depth of 100 feet. A mass increase below 1% was defined as negligible water ingress. The optimized configuration used a 0.1 mm layer height, four perimeters, a 1.25 extrusion multiplier, an approximately 260°C nozzle temperature, randomized seams, and adaptive cubic infill. Repeated testing produced mass increases between approximately 0.32% and 0.83%, demonstrating consistent performance under the tested conditions. Brick layering was also investigated as a method of disrupting continuous seam-aligned leakage pathways and reduced average water ingress by approximately 32% compared with conventional layering. Current work focuses on validating these settings across more complex geometries, improving top-surface sealing, and developing a standardized slicer workflow for manufacturing pressure-resistant components for underwater robotics.