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Computer Aided Machining (CAM) is the process of translating a CAD model into machine instructions that a CNC can execute. This module introduces key CAM concepts, including setting up toolpaths, selecting tools, and generating the G-code needed for CNC operation.

Basic CAM Concepts

• Toolpaths: Toolpaths determine the movement of the cutting tool relative to the workpiece. Strategies such as contour cutting, pocketing, and drilling are used depending on the desired outcome.
• Operations: CAM operations are the specific tasks needed to machine the part, including profiling edges, cutting pockets, or drilling holes. Each operation requires setting parameters such as cutting depth, speed, and feed rate.
• Tool Selection: Tools vary by size, shape, and material, with each type optimized for specific operations and workpiece materials. Tool selection can be limited by the collet capacity (ER11, or ≤7mm), spindle torque and speed and material selection. Generally, select a right-size tool for the job and consider your operation order to minimise changes (due to the lack of a toolchanger).
• Feeds and Speeds: Feeds and speeds refer to the cutting parameters, specifically the feed rate (how fast the tool moves across the surface of the material) and the spindle speed (how fast the tool rotates). Selecting the appropriate feeds and speeds is crucial for achieving optimal cutting performance, prolonging tool life, and ensuring a quality finish. Incorrect settings can lead to tool wear, poor surface quality, or even tool breakage. Read more about feeds and speeds.
• Chips: In CNC machining, heat is a major issue to be managed. The tool spins at very high speeds, and excess heat dulls cutters, burns workpieces and increases deflection and tool breakage. The ideal form is the chip, a small piece of material relative to the tool’s cutting edge, which due to its mass and way it’s created holds the heat generated and moves it away from the cutter and the workpiece.
• Together, Feeds and Speeds and Chipmaking are the way that heat is managed in machining. A well formed chip is large enough to carry away the heat generated; it will only be formed if the physics of how the cutter moves across the work surface are coordinated.

Workflow in Fusion 360

In Fusion 360, CAM is integrated directly, enabling a smooth transition from CAD to CAM. CAM tools are found by changing the Workspace to Manufacture. The typical workflow involves:

1. Define Machine and Tools: Define machine parameters, including how the machine moves and specifying a post file that prepares toolpaths for compatibility with the specific CNC. Select the appropriate cutting tools from the tool library or define new ones if necessary. This is typically performed once for the machine and updated when new tools are added.
2. Create a ‘Setup’: The setup defines workpiece dimensions, material, reference point and the coordinate system. There can be multiple setups, for example when reorienting the workpiece.
3. Toolpath Creation: Once you have a setup defined, select the desired operations and generate toolpaths. Feeds and speeds are set during this step. This usually is a two-step process, with operations classed as either:
   1. Roughing: Efficiently cut away large amounts of material using operations designed for fast removal of large amounts of material, at the expense of quality. (e.g. 2D Adaptive Clearing, 3D Adaptive Clearing, Face).
   2. Finishing: Use slower techniques to remove remaining material, with movements tuned to give high-quality finishes. (e.g. Contour, Parallel)
4. Simulation: Use the simulation tool to verify the toolpaths and avoid collisions or errors before machining. You will be able to see how the machine will move and where and why you might have issues. Fusion 360 virtually cuts your workpiece mimicking the results you should expect.
5. G-Code Generation: After verifying the setup, toolpaths, and reviewing the simulation, post (export) the G-code to control the CNC machine during production. The files generated will be loaded onto the CNC.

Actions and Outcomes for This Module

• Set Up a CAM Project: Define the workpiece and select tools for your CAM project in Fusion 360.
• Create Toolpaths: Develop basic toolpaths and understand different machining strategies such as contouring, pocketing, and others.
• Simulate Toolpaths: Run simulations to verify the correctness and safety of the toolpaths.
• Generate G-Code: Post G-code for use with the CNC machine to execute the operations.
• Instructor Review: Share your CAM setup with the instructor for review before moving to the in-person training. You will need to export your Fusion 360 file as .f3d and send this to the instructor.