The goal of this course is to teach persons with a technical background how to program and operate Computer Numerical Control (CNC) mills and lathes.
This course bridges the gap between what persons with a technical education know and what they must learn to begin using CNC machine tools. The types of parts, materials and machining operations that engineers, innovators, and niche manufacturers often use are featured. Work holding techniques well suited to prototype and short-run production are detailed and used as examples.
The learner is expected to have the following:
This course is designed for the following audiences:
CNC Machining is a very broad subject and there are many ways to do most things. Covering all options would fill volumes and is beyond the scope of any one book or course. The goal of this course is not to turn and engineer into a journeyman machinist. Rather, it is to show how to use CNC to make common types of parts, teach DFM principles, and help engineers become better designers and managers.
This curriculum was created using an Instruction Design process. Engineering educators and students from leading Universities, as well as practicing engineers in a variety of industries, were surveyed. This process determined the types of parts and materials covered in this course. Parts that are easier made using Additive Rapid Prototyping (RP) technologies were excluded.
By leveraging what anyone with a technical education knows, by focusing on the most common types of parts and materials, and by presenting best practices for prototype machining, learning objectives are narrowed considerably. Thus a remarkable amount can be achieved in a short time. For example, working engineers using this course have been taught to set up, program, and operate a CNC mill in less than 24 hours of combined classroom/lab time; including instruction in CAD/CAM.
This economy of instruction makes CNC accessible to almost anyone: from working engineers to students involved in design/build competitions, to undergraduate engineering students as part of a Design for Manufacturing (DFM) course or hand-on lab.
This course emphasizes an approach to CNC machining referred to as Subtractive Rapid Prototyping (SRP). SRP deals with small quantities of functional prototypes. Functional prototypes are made from materials like aluminum, steel and polycarbonate that cannot be produced with widely available additive Rapid Prototyping (RP) processes such as SLA (Stereolithography) or FDM (Fused Deposition Modeling).
SPR is not as simple to learn and use as RP. It takes more skill and often more time to apply. The main advantage of SRP is in materials. Almost anything can be machined. SRP parts are not just visual aids, they are structural components that can be tested and assembled as part of working machines.
Another advantage of SRP is that it teaches real manufacturing constraints typical of the aerospace, biomedical, consumer goods, and electronics industries -all which use CNC for mass production, molds and other tooling. RP does not reflect these constraints. A part that is easy to rapid prototype may be extremely difficult, expensive, or even impossible to manufacture. SPR provides the designer with feedback about the manufacturability of design that can save considerable time and money as a part moves from concept to product.
One of the biggest differences between making a few or many parts is in the design of work-holding fixtures. Prototype machining emphasizes quick, simple and cheap work holding solutions such as vises, clamps, screws or even glue or double-sided tape. High production parts allow the cost of fixtures to be amortized over larger quantities to justify the cost of more elaborate and efficient fixtures. This course emphasized prototype fixturing.