The purpose of this thesis is to and explain and to summarize, in a logical manner, all the experiments, the procedures and results obtained during a 5 months’ internship in PrusaResearch. Extrusion inconsistency artifact was investigated by means of the creation of a testing machine. The purpose of the testing machine is to collect data about the force and the speed supplied by the feeding mechanism in order to have a better understanding of the causes of the phenomenon. An attempt to control the pressure inside the nozzle is made by implementing a closed loop control. In conclusion, some proposals of sensor implementation are given to close the loop.