No matter which automated cutting method you choose, the steps for turning your idea into a finished object are the same. You create a computerized drawing, import to your CAM software, generate a cutting program, and load into your CNC. Let's look at each step individually to better understand how the process works. Step 1: Create a computerized three dimensional model or two dimensional CAD drawing of the object.
- Three dimensional Computer Aided Design software packages are commonly used to model parts.
- The model can be of a single part or an entire assembly. Alternatively, you can draw the same part using two dimensional CAD drawing software. Either option works for the automated cutting process flow.
- The output of this step is a 3D model to-scale or a 2D dimensioned part file.
Step 2: Import the 3D model or 2D CAD drawing to your CAM software.
- Computer Aided Manufacturing software controls machine tools used in the manufacturing process. Early versions of CAM software were simply post processors that generated start, stop, and motion commands to cut out the part based on the 2D CAD drawing.
- Today’s CAM software automates manual tasks in the work environment, increases the overall speed and efficiency of the software, uses built-in quality control measures, and embeds cost cutting techniques directly into the job.
- The CAM software’s main job is to convert the 3D model or CAD drawing created in Step 1 into a numeric code (NC) part program.
- Process expertise is embedded into the part program, creating consistent high quality results with minimal operator intervention. This includes the layout of parts on the work piece, called a nest, so that the motion path and cutting techniques are optimized.
- In summary, CAM software establishes the motion requirements and cutting parameters to be included in the part program.
Step 3: Generate a cutting program from the model or drawing you just imported.
- Once converted into an NC file (simply a file with numeric code to instruct a machine,) a part program can be created.
- Basic programs tell the machine when to move, where to move, and how fast to move. More advanced programs contain embedded information to optimize each job. Instead of relying on the knowledge of an experienced operator, the knowledge can be embedded into the NC file.
- Embedded knowledge helps your CNC automatically control flow rate, pressure settings, the length and timing of lead-ins and lead-outs, the direction of the cut, the order in which parts are cut, height control commands, cut speed, and much more.
Step 4: Load the program onto your CNC
- A computer numerical control (or CNC) typically consists of a human machine interface (HMI) and internal processing capability. The unit is connected to the cutting machine and provides motion and other related instructions to the table drive motors/amplifiers, cutting tool, and associated equipment. CNCs range in size and complexity.
- The CNC software takes inputs from the operator console, reads instructions from the part program and executes it all by sending signals to control the entire cutting operation.
- While the CAM software programs everything that can be planned ahead of time, the CNC software executes the part program, coordinates the motion and cutting system with precise timing, and reacts to the feedback from the cutting environment.
- The key inputs to the CNC are the part program, feedback signals from cutting system, table and lifter, and operator console switches.
- By pushing the start button you are starting the part program. The CNC walks line by line through the part program and communicates with the different components of the cutting system through electrical signals.