Which design approach can improve the stability of overhangs during FDM printing?

In Fused Deposition Modeling (FDM), overhangs are sections of a print that extend beyond the layers below without direct support. To improve the stability of these overhangs during the printing process, it is beneficial to add gradual transitions with fillets. This design approach allows for a smoother shift from one surface to another, thus distributing the forces acting on the overhang more evenly and reducing the risk of sagging or collapsing.

Fillets create a rounded corner instead of a sharp angle, which helps in both increasing the surface area that the print head can adhere to and minimizing the stresses that occur at the junctions of different parts. When the material is laid down in layers, a gradual transition helps maintain structural integrity and allows the extruded material more time to cool and solidify before additional weight is added above it. This technique also enhances the overall aesthetic of the print by providing a more polished look.

In contrast, other approaches may not effectively enhance overhang stability. Angled surfaces might reduce the immediate need for support but can result in steep transitions that may still struggle with material sagging. Avoiding all fillets can create stress concentration points and lead to weak connections between parts of the design. Designing thicker walls can add strength but