In this project we built-up a 3D printer aiming the fabrication of microfluidic devices. It is based on the technology of Fused Deposition Modelling, cheaper and simpler than conventional photolithographic methods to manufacture microchannels, adding flexibility in the development and integration of sensors and devices. In this case we present a complete sealing case, permitting future developments of `lab-on-a-chip' devices. We also optimize printing parameters for ABS and PLA microchannels.