A number of advanced manufacturing techniques are used in the design, development and construction of unmanned vehicles (including UAVS, UGVs, USVs and other robotic/autonomous platforms) and their component parts. CNC (Computer Numerical Control) machining is a method of advanced manufacturing that uses computers to control a variety of machining tools such as lathes, drills, mills and routers. Data from a 2D or 3D CAD drawing is converted into instructions understandable by the computer that precisely control the machine speeds, feed rates, co-ordinates and other parameters. CNC machining can be used with a variety of materials used in the construction of unmanned vehicle components including metals, plastics, composites and foam. It provides high levels of precision and repeatability compared to manual machining and is capable of producing complex three-dimensional structures. Simpler CNC machines can move in two or three axes and more advanced machines have the ability to move laterally, longitudinally and rotationally. CNC machining is used to produce rapid prototypes, as well as high-tolerance parts for unmanned vehicles including airframes for UAVs. 3D printing originally referred to a process in which powdered material was mixed with a binding compound to form successive layers of the structure, but the term has grown to encompass other methods of additive manufacturing such as fused deposition modelling, which injects liquid thermoplastics that cool to form each layer. 3D printing can be used to construct many non-electronic parts for unmanned vehicles, such as UAV propellers, frames and landing gear. It is ideal for rapidly prototyping parts and producing low numbers, but the process does not scale well to large production runs. 3D printing does not produce exceptionally fine detail and printers capable of printing larger objects are uncommon and expensive. Laser sintering is a form of additive manufacturing that uses a laser to fuse together powdered particles of metal, plastic, glass or ceramic, binding them together to create the structure. Unlike other methods of layered manufacturing, it is not necessary to create additional support structures for overhanging parts, since the part will always be surrounded by unsintered powder and will never be left hanging in free space. It is therefore possible to create more complex geometries than with other additive manufacturing methods. Laser sintering is not ideal for creating certain structures such as large flat surfaces or smooth finishes, due to thermal distortion. Laser sintering technology is also extremely expensive due to the high complexity of the machinery.