# CNC basics > Routers and carving machines: bits, materials, toolpaths and the files a CNC needs from a MyLaserTools design. ## What is CNC machining? CNC stands for Computer Numerical Control. A CNC machine moves a cutting tool (router bit, end mill, or drill) along programmed paths to cut, carve, or drill material. Unlike a laser, which removes material with heat, a CNC router removes material mechanically, which makes it well-suited for thicker stock and materials that do not respond well to heat. For makers and small shops, CNC routers are commonly used to cut furniture parts, signs, molds, jigs, enclosures, and decorative panels. Desktop machines like the Shapeoko, X-Carve, and Onefinity have made CNC accessible to hobbyists, while larger professional machines like those from ShopBot and Multicam are used in production environments. ## Types of CNC machines **CNC routers** are the most common type for woodworking and sign making. They use a spinning router bit to cut through plywood, MDF, solid wood, soft metals, and plastics. **CNC mills** are more rigid than routers and are used for precise work in metal, aluminium, and engineering plastics. Popular desktop mills include the Bantam Tools Desktop CNC and Haas machines in professional shops. **Combo machines**, such as the Snapmaker, swap between a CNC spindle, a laser head and a 3D print head on one frame. They suit small parts and soft materials. ## Common materials - **Plywood (6 to 18 mm)**: The most widely used CNC material. Birch and Baltic birch cut cleanly with a sharp bit. Custom joint designs rely on knowing your exact thickness. - **MDF**: MDF has a uniform surface useful for painted signs and jigs. Machining produces fine dust. Use effective dust extraction and follow the material and machine guidance for respiratory protection. - **Solid wood**: Pine, oak, maple, and walnut are all common. Grain direction affects cut quality and tearout. - **HDPE and acrylic**: Plastics machine well with the right bit and feed rate. Often used for jigs, fixtures, and functional parts. - **Aluminium**: Machinable on rigid desktop mills with appropriate feeds, speeds, and cooling. Not suitable for entry-level routers. - **Foam and insulation board**: Fast to cut, great for molds, props, and packaging inserts. ## Key terms - **Toolpath**: The programmed route the cutter follows. Includes cut depth, direction, and step-down per pass. - **Feed rate**: How fast the machine moves horizontally through material, usually in mm/min or in/min. - **Step-down (depth of cut)**: How deep the bit cuts on each pass. For wood, about half to one times the bit diameter. - **Tabs**: Small bridges left uncut to hold the workpiece in place until machining is complete. - **G-Code**: The low-level language that tells the machine exactly where to move and how fast. Generated by CAM software from your design. - **Climb and conventional milling**: Two directions the bit can travel along a cut, with or against its spin. Climb milling often leaves a cleaner edge in wood; conventional milling is gentler on a light machine. Try both on a scrap and use the one that cuts cleaner on your router. - **Pocket**: A toolpath that clears all the material inside an outline down to one depth. A carved map is a stack of pockets, one per step. - **V-carve**: Carving with a V-shaped bit that goes deeper where a shape is wider, so lettering and coastlines get sharp corners and fine points. ## File formats and software **SVG and DXF** are the starting point for most CNC designs. You draw or generate the shape as a 2D vector, then import it into CAM software to generate toolpaths. **CAM software** turns your design into G-code. Popular options include Vectric VCarve, Carbide Create (free), Fusion (free for hobbyists) and Easel. VCarve is a common choice for signs and woodworking. For a box or jointed design, enter the measured material thickness. A router leaves rounded internal corners, so square-fitting joints may need corner relief such as dogbones. Cut a small fit test before machining every panel. ## Getting started - Measure your actual material thickness with calipers, not the nominal size. A sheet sold as 12 mm is often 11.6 mm. - Secure your workpiece firmly with clamps, screws, or double-sided tape before running a job. - Run an air cut first (machine raised above the material) to check the toolpath looks correct before cutting. - Start conservative: slower feed rates and shallower passes preserve bits and prevent mistakes. - Wear hearing protection and a dust mask. CNC routers are loud and produce fine wood dust. ## MyLaserTools for CNC Use the joinery and enclosure tools to draw panel outlines. Check cutter access, internal corner relief and joint clearance in CAM before turning those outlines into toolpaths. - **Box Generator**: Set the box dimensions and measured material thickness to generate finger-jointed panels. Adjust the fit allowance and cut a test joint; a router may also need internal corner relief. - **Joint Panel Generator**: Generates shelf and panel joints for furniture, dividers, and cabinets. Choose joint type (T-slot, box joint, or cross), set material thickness, and download cut-ready SVG. - **Booknook Case Generator**: Builds a full bookshelf insert case with back panel, side walls, and shelves. All slots are custom. Ideal for CNC routing from 9mm or 12mm plywood. - **3D Box Generator**: Exports an STL or 3MF of a box shape for reference or mold-making, alongside the flat SVG panels. Useful for verifying fit before machining. - **Map Designer**: Carve topography and lake depth maps as terraced relief: one SVG per step to pocket, or an STL for a 3D carving. The Learning Center guide on carving maps walks through both. --- Read online: https://www.mylasertools.com/learn/basics/cnc