After designing the model to print in CAD, it must be sliced. The model will be sliced horizontally in layers and compiled into commands (G-Code) that the 3D printer will execute. Slicing is a very important process. Pay close attention to the parameters. These will all vary based on the detail and purpose of the model. Layer height, shell thickness, and infill are all very important to print strength and detail. If overhangs are needed, use the software to generate supports, to ensure that the print comes out as designed.
There are a few different slicers available. Some are free ( popular free ones are Cura or Slicr) and some cost money. I use a premium slicer called Simplify3D. I spend a good bit of time analyzing the model to ensure an optimum slice before I print.
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