The present research work focuses on the validation of water velocity in long channels of microfluidic structures manufactured by 3D printing. The current assessment of devices with microchannels of considerable distances (60, 80, 100 mm), manufactured with 3D technology, seeking to identify the most optimal and feasible method to obtain accurate results. To achieve this, a methodology is established to ensure the collection of relevant data for a detailed analysis of the fluid velocity. Several steps are followed to minimize defects in the devices, from printing using the Form 2 3D printer from Formlabs, to subsequent washing and curing. Data measurement is carried out in a specialized laboratory in the microfluidic field, allowing precise manipulation of the fluid and specific testing to obtain the necessary results. The findings reveal that the behavior of water varies significantly between different devices. The recorded velocities exhibit alterations that correlate directly with channel structure, demonstrating different levels of stability. This analysis not only contributes to the understanding of water behavior in microfluidic devices, but also establishes fundamental points for the design and optimization of microfluidic systems that seek precise and constant flow control.