Computer Aided Manufacturing, or CAM for short, is the process of using software to simplify the setup, programming, and validation of CNC (Computer Numerical Control) machines. CNC machines run off code called G-code and M-code. M-code is typically the machine control like turning on/off a spindle and changing a tool. G-code is typically the code that controls the movement of the tool.

Using a CAM program like Autodesk Fusion lets us select geometry from a digital 3D model, determine where and how the tool will remove material, and validate it with simulation before sending it to a physical machine. This process lets us program toolpaths and export them to various machines through Post Processing.

It doesn't matter if you are programming a small desktop CNC machine or a large multi-axis machine the process is the same. We will follow the key steps to understand the process.

• Digital Twin Setup - Defining the part, stock, and workholding in a 3D model that matches what we have at a physical machine.
• Process Planning - Looking at a 3D model or detailed drawing and coming up with a plan for how to machine the part. This often is done "on the fly" once you have enough experience, but it is good to plan out your tools, order of operations, and how you are going to hold the part in multiple setups.
• Tool Library Setup - Often times this is done once and added to, but having a digital tool that matches a physical tool is key to machining. Knowing how fast the tool can spin and move through material, its geometry and coating, and its position in a tool changer.
• CAM Setup - This is the digital setup of the stock, vise or workholding, and the location of the WCS or Work Coordinate System.
• Setup1 - A setup is a single position or orientation of the part/stock on a machine. Some parts can be machined in a single setup, but most will require at least two.
• Setup2+ - If a part needs to be flipped over or machined from another orientation, this will mean additional setups. Each setup will have its own coordinate system definition and this must be a spot you can measure and validate physically. Often times this is a spot on custom workholding like a soft-jaw, or it could be a stop installed on a vise.
• Output - Output involves the creation of a Setup Sheet, a document that details the CAM setup, tools used and general process settings. This also involves Post Processing, which is the use of a machine specific post configuration that converts the toolpaths created in Fusion into machine-readable G-code. This step lets us convert the generic toolpaths for various machines, but note that the settings such as spindle speed and feedrates do not change. So there are limitations to this and you should always program your parts for a known machine for the correct feedrates.