Closed-loop machining is not widely used or taught. The technique utilizes a machining element on the end of a robotic
arm that behaves much like the arm of a sculptor. As explained in Effective Robotics
the parts of the arm need not be made with precision, nor do sensors need to be linear, because the sculpting precision is provide by the closed-loop control enforced by the electronics (the sensing and computing). Closed-loop control navigates
to positions using continuous feedback rather than relying on the precision with which parts are made.
Complex shapes such as those of turbines, propellers, and lenses, can be made repeatedly and in great variety because what is made is up to the software.
Such a tool is potentially a great force for lowing the cost of offering machine shop services. Instead of needing to buy a great many expensive tools, each with their limited applications, the business can begin profitably at a low volume of customer sales.
This method produces another positive consequence. If arbitrary shapes can be made without extra expense and time, the design of products, including specialized machines and tools, will prompt further innovation.