Undercuts are options that cannot be|that can't be|that can't be} machined with commonplace instruments, irrespective of how the part is rotated, as a result of|as a outcome of} the slicing instruments can not entry all surfaces. If square aluminum extrusions have been manufactured with CNC machining, then their grooves would be considered undercuts. In CNC machining, start-up prices are mainly related to process planning. This step requires guide input from an expert, so start-up prices are normally comparatively travel underwear excessive when compared, for example, to 3D printing, the place process planning is very automated. They are still much decrease than formative manufacturing processes although , which require the preparation of customized tooling.