What does a CNC programmer need to create before machining can begin?

The need for a CAD model of the part is essential before machining can begin because it serves as the foundation for the CNC programming process. The CAD (Computer-Aided Design) model provides a detailed and precise digital representation of the part, which includes dimensions, geometry, and features that need to be machined. This model is crucial as it allows the programmer to generate the CNC code, or G-code, that instructs the CNC machine on how to move and operate to accurately produce the part.

Creating the CNC program starts with interpreting the CAD model, which informs decisions related to tool paths, speeds, feeds, and the selection of tools necessary for the machining process. Without the CAD model, there would be no reference for the design, making it impossible for the programmer to effectively translate the part design into machine code.

While other choices may pertain to the machining process in various ways, they do not serve as a direct prerequisite for initiating machining. A manual for the CNC machine is useful for understanding operational procedures, a physical prototype could aid in verification but is not necessary before programming, and a stock inventory list informs resource availability but does not influence the creation of the machining program. Therefore, establishing a CAD model is a fundamental step that enables the subsequent procedures