Simple and low-cost qualitative test of wear in 3D-printer extruder nozzle by using diffraction patterns

Abstract

Nowadays, 3D printing is tool widely used in areas such as physics, engineering, medicine and STEM education, for instance. One of the reasons why 3D prints could present low quality, causing poor layer adhesion, print blobs, and uneven or rough print surfaces; to name a few, is due to wear on the extruder nozzle and filament clogging. Verification of this wear is generally carried out by visual inspection in a qualitatively approach or using an object (with a known diameter) that is introduced into the extruder which serves as a reference. Due to this, an alternative low-cost and simple qualitative test is proposed. This test analyzes the diffraction pattern generated by the circular aperture of the nozzle under test and compares it with the pattern generated by a nozzle without wear and of the same dimensions (the qualitative results will allow the user to decide whether or not to change this component). A simple modification to a commercial laser pointer is also proposed, which will create a device that performs this test in a low-cost, simple, and portable manner.