What effect does excessive wall thickness have on the internal structure of a printed object?

Excessive wall thickness in a 3D printed object can indeed lead to internal stress and potential cracking. When walls are printed thicker than necessary, the material in these areas can cool at different rates compared to the rest of the object. This differential cooling can create uneven thermal contractions within the material, leading to the development of internal stresses. These stresses can accumulate over time, especially when the object is subjected to external loads or environmental changes, increasing the likelihood of warping or cracking.

Additionally, thicker walls may obstruct proper internal layer adhesion, as the flow of molten filament can become less predictable, which can further exacerbate the internal stress issues. The result is a physical structure that is more susceptible to failure when subjected to forces or impacts that it might otherwise withstand if designed with appropriate wall thickness.