You may want to know why. Where a part can be expressed with some combination of analytical geometry eg: Cone, torus, sphere, trapezoid, cube, cylinder, etc..

You may want to know why. Where a part can be expressed with some combination of analytical geometry eg: Cone, torus, sphere, trapezoid, cube, cylinder, etc... we have long established means and methods of production available and they are generally efficient ; however, shapes derived from both curves of a higher degree than conic, and or paths that are themselves non analytical in nature, or employ multiple profiles blended, tend to become general b-spline geometry types which require higher order means and methods. Secondly, inspection of these higher order parts often is more expensive as well. Simple analytical means will not suffice. Templates, CMM machines, point sampling, scanning are all likely solutions, all typically more expensive and computationally heavy requiring computer assistance today. (We used to make these sorts of things without computers, and doing so required serious skill not always available.) A simple fillet as opposed to a chamfer, requires more machining given more care and requiring higher order path planning software and or operators able to employ that software to machine successfully. These same dynamics apply to the geometries I mention above and the cost tends to multiply across multiple manufacturing centers or cells as well as downstream operations, such as inspect.