What signifies the end of one layer and the beginning of the next in FDM?

The transition from one layer to the next in Fused Deposition Modelling (FDM) is primarily indicated by the movement of the build platform. As each layer is printed, the build platform descends incrementally after the nozzle completes its task of laying down material for that specific layer. This downward adjustment allows the nozzle to move closer to the previously printed layer for the commencement of the next layer.

This process is crucial for ensuring that the layers adhere correctly to one another, which is essential for the structural integrity of the final printed object. The stepping down of the build platform also ensures consistent layer height throughout the print, contributing to the overall accuracy of the model being created. Each descent corresponds to a set layer thickness, which is a key factor in determining the print resolution and quality.