What is the working logic of a 3D printer?

The working principle of 3D printers is generally based on a method called additive manufacturing. Here is a detailed explanation:

1. **Modelling**:
First, a 3D model needs to be created. This model is usually designed with a CAD (Computer Aided Design) program. This designed model is converted into a format that the 3D printer can understand (usually with the `.stl` extension).

2. **Layering**:
The 3D printer takes this `.stl` file and divides the model into thin layers. These layers create the road map that the printer will follow when converting the model into a physical object.

3. **Print**:
A 3D printer builds the model layer by layer by melting or sintering (combining powders) materials, usually a thermoplastic filament or resin. This process is carried out by a head called a nozzle. The nozzle spreads the filament, which melts at a certain temperature, layer by layer and on top of each other. The filament freezes immediately after spreading on the surface and takes its solid form. When all layers are completed, the model is ready in completely solid form.

4. **Conclusion**:
As a result, 3D printers transform a digital model into a physical object by building layer by layer. This technology is used in many applications such as rapid prototyping, customized manufacturing, and the creation of complex geometries.
This technology was introduced by Charles Hull in 1984 and has developed rapidly since then. Nowadays, 3D printers are used in many fields such as industrial design, medicine, education and personal use.

.Let's add more details to the working principle of 3D printers:

**Support Structures**:
Some 3D prints need support structures to keep certain parts of the model from falling off by gravity. These structures are created during printing and removed after printing is completed.

**Material Variety**:
3D printers can work with a variety of materials. The most commonly used material is PLA (Polylactic Acid) or ABS (Acrylonitrile Butadiene Styrene), which is a thermoplastic filament. However, there are 3D printers that can also print with other materials such as metal, ceramics, food, and even biological materials.

. **Surface Treatments**:
After the printing is completed, surface finishing is usually done. This may include removing support structures, sanding the model, painting or other surface treatments.

**Technology Diversity**:
The FDM (Fused Deposition Modeling) technology described above is the most widely used technology in 3D printers. However, other 3D printing technologies such as Stereolithography (SLA), Selective Laser Sintering (SLS), Direct Metal Laser Sintering (DMLS) are also available. These technologies offer different advantages for different materials and applications.

3D printers are used in many applications such as rapid prototyping, customized manufacturing, creation of complex geometries, and even personalized medical implants. This technology can speed up manufacturing processes and enable the creation of designs that were not possible before.