What is PESU?

Designing for PESU (Polyethersulfone) in 3D printing requires special considerations to ensure optimal print quality, strength, and durability. Here are key points to keep in mind when designing parts specifically for PESU:

Support Structures: PESU has a high risk of warping, so avoid steep overhangs (angles over 45°) and complex geometries that require excessive support. If overhangs are unavoidable, design in such a way that supports can be easily removed or are minimized.

Gentle Curves: Opt for gradual curves and smooth transitions in your design to help reduce stress during cooling and improve strength.

Print Orientation: Carefully consider the orientation of the part during printing. For instance, parts with a high vertical load should be printed with the build height aligned with the Z-axis to maximize strength.

Warpage Minimization: Position parts so that they don’t excessively cool unevenly. Aligning flat surfaces horizontally can minimize warping.

Thicker Walls: To ensure strength, use thicker walls, generally around 2-4 mm depending on the part's function. Thin walls may lead to failure under stress or impact.

Optimal Layer Height: A layer height of 0.1 mm to 0.2 mm provides a balance between precision and printing speed. Thicker layers might cause adhesion problems, and thinner layers may increase print time without significant quality improvements.

Infill Density: Use 40-60% infill for most parts, depending on the strength needed. Higher infill may be necessary for critical load-bearing parts, but it will also increase print time and material usage.

Infill Pattern: A grid or triangular pattern is usually preferred for strength. It helps with layer bonding and provides better support during cooling.

Detailing: PESU is typically not ideal for extremely fine details or intricate features due to its higher melting temperature and print complexity. Aim for larger features and avoid delicate or thin sections.

Smooth Surfaces: Post-processing is easier when surfaces are designed to be smooth and without significant overhangs. This minimizes the effort required for sanding or other finishing methods.

Threaded Inserts/Features: If incorporating threads or inserts, design them larger than usual, as PESU’s high stiffness can make fine threading challenging.

Allowance for Shrinkage: PESU has a tendency to shrink during cooling. Incorporate tolerances that account for this thermal contraction, especially in high-precision parts, to ensure parts fit properly after printing.

Fit and Tolerances: Allow slightly looser fits to compensate for the minor warping and shrinkage that may occur during cooling.

Thin Sections: Avoid thin, flat sections in your design that may warp or curl during printing. Instead, use thicker sections and consider adding fillets or radii to corners to improve durability.

Support Design: If supports are necessary, make sure they are easy to remove and avoid excessive contact with the part surface. You can design overhangs in such a way that they minimize support usage, or use breakaway supports.

Bridging: For sections that require bridging, ensure that your design includes wider spans and thicker sections that allow for the material to solidify without sagging.