Selecting a 3D printer is not an easy task but when you define your requirements, then it becomes easy. First, the nature of the projects to be developed should be determined. For basic models and prototypes, it is recommended to use Fused Deposition Modeling (FDM) printer as it is relatively cheaper and easier to use. If you require very detailed prints, then go for Stereolithography (SLA) printers because they are very precise.
Subsequently, assess the build volume; projects of greater size need printers with larger build volumes. Compatibility of materials is also a factor; the printer should be compatible with the filaments or resins you want to use such as PLA, ABS or PETG.
Also, do not forget about the assembly and usability aspects of the chosen design. Depending on the type of printer, it comes either in a ready assembled form or needs to be assembled. Last but not least, it is crucial to look at the community and support that the particular printer model has to offer since a robust community is a source of helpful information and tips. In this way, evaluating these aspects, you can choose the optimal model of a 3D printer.