A Guide to Preparing Your Files for CNC Machining

Understanding Digital Files: The Difference Between 2D and 3D

To ensure we can turn your project into a perfect physical item, it's crucial to understand the journey from your digital file to our CNC machine. The type of file you provide directly impacts how we can program the machine and, ultimately, the final quality and accuracy of your product.

• 2D Files (JPG, PNG, SVG, DXF, PDF): These are flat images or drawings. Think of them as a blueprint on a piece of paper. They only contain information for the length and width of an object. While a high-quality SVG (Scalable Vector Graphic) or DXF (Drawing Exchange Format) file is excellent for cutting out a specific shape, it doesn't contain any information about depth, curves, or three-dimensional features.
• 3D CAD Files (STEP, STL, IGES): These are the digital equivalent of a physical model. They contain all the necessary data for a three-dimensional object—its length, width, depth, and all its contours and surfaces. These files are essential for any project that requires milling, carving, or any detail beyond a simple cutout.

Why this matters: We can't automatically turn a flat image (like a JPG) into a 3D model. We need to manually recreate your design in 3D CAD software, which takes time and can introduce potential inaccuracies if we don't have all the necessary information. Sending us a proper 3D CAD file from the start will always result in a faster and more accurate outcome.

CNC Toolpath Strategies: How the Machine Reads Your Design

Once we have a suitable file, the next step is to create a toolpath. This is the set of instructions we program into the CNC machine that tells the cutting tool exactly where to go, how fast to move, and how deep to cut. The toolpath strategy we choose is based entirely on the complexity of your design and the material we're using.

Here are some of the most common toolpath strategies we use:

1. 2D Profiling: This is the most basic toolpath. It follows a single line or vector, like a simple cutout. Think of it as a laser cutter following the outline of a shape. We can program the tool to cut on the inside, outside, or directly on that line. This is perfect for designs from a clean SVG or DXF file.
2. Pocketing: This strategy removes material from an area defined by two or more lines. For example, if you wanted to carve out a square recess in a piece of wood, we would define the outer boundary and the inner boundary, and the tool would "pocket" out the material between them.
3. V-Carving: This specialised toolpath uses a V-shaped bit to create a carved effect. The depth of the cut changes based on the width of the lines in your design, allowing for beautiful, intricate lettering and detailed artwork.
4. 3D Carving/Roughing & Finishing: For complex 3D projects, we often use a two-stage process.
   • Roughing: We use a large cutting bit to quickly remove the bulk of the material, getting the part close to its final shape. We might use a Zig-Zag pattern for speed or an Adaptive Clearing strategy, which is a more efficient method that maintains a consistent load on the tool, extending its life and allowing for faster cutting.
   • Finishing: We then switch to a smaller, finer bit to create the final, smooth surface. Strategies like a Parallel Finishing or Spiral Finishing toolpath are used to follow the curves and contours of the 3D model to achieve a high-quality finish.

To help us get started on your project, please remember to provide as much information as possible, including:

• The type of material you want to use.
• All key dimensions and tolerances.
• The intended purpose of the final part.