范文
How does a 3-D printer work? Imagine a 2-D, in another word, a conventional paper printer, except the “ink” and the “paper” for a 3-D printer are one thing - the feed material, which is mostly plastic.
To print out a solid object, you need to “paint” the structure of the object using a three-dimensional modeling software. The software dissects the 3-D model along one dimension, into many thin layers, each layer representing a cross-section visual of the structure. We could consider the solid structure in press as consolidated flat sheets - exactly like the integration process in Calculus. On each layer, the nozzle spews out fluid material to fill the layer’s pattern.
How does the nozzle know where to deposit material, in other words, the locations of points in each nearly two-dimensional layer (A layer still has a thickness albeit very small, hence the word ”nearly”)? It takes precise directions from the “map” - the digital model, moving with the motored towhead along two rails in one direction horizontally while the printer bed, which carries the “print-out”, slides in the perpendicular direction horizontally, thus setting the x and y coordinates of each point to paint. This way the exact spots in the pattern on each layer will be touched - painted with “ink”. After one layer is done, the printer bed lowers a little, allowing another layer to pile on, thus to build up the height.
