In what scenario would you want to avoid adding support material in FDM?

Adding support material in Fused Deposition Modeling (FDM) can often be necessary to ensure the successful printing of certain designs, but there are scenarios where it is advantageous to avoid it. In the case of designs without overhangs, support material is unnecessary because the layers of the printed object can be built upon one another with adequate structural integrity.

When there are no overhangs, every layer has sufficient support from the layers beneath it. This makes the printing process cleaner and more efficient, as support materials can complicate post-processing and may require additional cleanup steps. Moreover, avoiding support reduces material waste and can enhance the overall smoothness and aesthetic of the final print, since there would be no remnants of support structures that need to be trimmed or sanded off.

In contrast, tapering, thicker walls, and complex geometries often present challenges that may require the use of support materials to ensure successful printing. For instance, tapering could lead to angles that necessitate some support, while complex geometries frequently feature overhangs that also need stabilization during the printing process. Therefore, the scenario where support material is not needed is specifically when the design has no overhangs.