In the first phase of 3D printing, the 3D model is divided into horizontal partitions or layers. The supposed cut leads to the construction of a triangular network in the modeling software. The nozzle installed at the end of the 3D printer is one of the most effective components of the final print output. The nozzle is the most attractive component of the 3D printer. Generally, people are interested in watching the first few layers of print coming out of the nozzle. One of the most flexible parts of 3D printers is the capability to alternate nozzles for different printing applications. Nozzles have various shapes and sizes leading to the realization of the same function. Another imperative component in printing is the diameter of the nozzle opening, which has a tremendous impact on the quality of print details. This effect applies not only to the width of the layer lines but also to the height of the layers. Previously, changing the nozzle for printing with a different diameter was done manually with special wrenches. The purpose of this research is to automatically alternate the diameter of the nozzle according to the 3D model of the input, detection of the surroundings, and detection inside the shape. In addition to eliminating manual and time-consuming tasks, this process improves the printing time and can realize printing in different layers with different diameters. This research aims to design a new algorithm in the production of G-Code, how to move the nozzle, and apply the corresponding hardware changes to achieve this objective