Introduction
Fused deposition modeling (FDM) is a widely used additive manufacturing technique valued for its affordability and accessibility. Despite its widespread adoption in education, prototyping, and hobbyist use, FDM often suffers from quality and consistency issues. Common problems such as warping, stringing, first-layer adhesion, or dimensional inaccuracies reduce the functionality and reliability of 3D-printed prototypes. Understanding the causes of these issues is essential to improving print quality and expanding the applicability of low-cost 3D printing.

Methods
A series of standardized models were manufactured using desktop FDM printers under controlled conditions. Key variables such as nozzle temperature, material type, layer height, cooling, and filament quality were systematically investigated. The manufactured pieces were evaluated through visual inspection and dimensional measurement to assess the presence and severity of defects. Environmental factors and hardware calibration (e.g., bed leveling) were also considered.

Results
This study identified clear correlations between specific printing parameters and the emergence of imperfections. Among the findings is that warping is strongly influenced by material choice and bed temperature. An excess of deposited material is a consequence of non-optimal nozzle temperature selection. Additionally, filament quality and printer maintenance were found to have a significant impact on print reliability.

Conclusions
The findings of this work highlight the importance of parameter optimization and equipment upkeep in achieving consistent FDM print quality. A set of practical guidelines is proposed to help users diagnose and mitigate common printing issues. These recommendations aim to support both novice and experienced users in enhancing the performance of their FDM fabrications. Ultimately, this research contributes to the broader goal of making desktop 3D printing more reliable for functional and engineering-oriented applications.