In order to make an I-phone 5c case first download a case from a website. When you are printing your case your going to want to have it on 240 degrees, 20% infill, 0.15mm line height 200mm/s for travel and extrusion. no rafters, only supports. This is going to be your epilog laser setting raster image at with 100% speed, 60% power. It relates to engineering because your building and doing some of the engineering steps.