CNC Basics

Explore & Discover

CNC machines are basically robots that follow your digital drawings to cut, carve, or engrave real materials. They're in makerspaces, factories, and garages all over Utah. Start by watching "How CNC Machines Work" on Tested's YouTube channel — look for the video with Adam Savage. Then find a local makerspace: check Salt Lake City's Makerspace at slcmakerspace.org or Utah Fab Lab. Many offer free or cheap teen memberships. If you can visit, do it — watch a machine run and notice how it moves in X, Y, and Z directions. Notice that everything the machine does started as a digital file someone designed. You're ready for the next step when you can name the three axes a CNC machine moves in and describe what the cutting bit actually does to the material.

Learn the Basics

CNC machines need two things: a design file and G-code (the language machines speak). Visit Thingiverse at thingiverse.com and browse files tagged "CNC." Download one simple design and open it in a free viewer. Then go to ncviewer.com and paste or upload a sample G-code file — watch the simulator trace every tool path. G-code looks intimidating but it's just a list of coordinates and speeds: G1 X10 Y20 F500 means "move to position 10,20 at feed rate 500." Read the beginner G-code reference at cnc.com/g-code-list. Understand just five commands: G0, G1, G28, M3, M5. You don't need to memorize them — just recognize what they do. You're ready for the next step when you can read a five-line G-code snippet and describe in plain words what the machine would do.

Build Your First Project

Design your first CNC project in Easel, the free browser-based CNC design tool at easel.inventables.com. Create a free account. Design a simple name badge or simple shape (keep it under 4 inches square). Use only the rectangle and text tools — don't try to be fancy yet. Set the material to MDF (medium-density fiberboard) and the bit to 1/8 inch straight. Look at the cut depth settings: full depth cuts all the way through, partial depth just engraves the surface. Export your design file. You haven't cut anything yet — this step is all about design. Show your design to an adult or makerspace instructor and ask: "Would this actually work?" Listen to their feedback. You're ready for the next step when you have a design in Easel that an adult has reviewed and said is safe to cut.

Experiment & Iterate

Now simulate the cut before touching any real machine. In Easel, use the "Preview" feature to watch your design's tool path animate. Check: does the bit lift when moving between parts? Does it cut in the right order? Change one setting — the feed rate — and preview again. Notice how speed affects the quality estimate. Then import your design into a free G-code simulator at camotics.org (download is free) and watch the 3D simulation of every cut. Camotics shows you if the bit would collide with the material clamps. Fix any problems you find. This simulation step is what professional machinists do every time — it's how you avoid expensive crashes. You're ready for the next step when your design runs through Camotics simulation with zero collisions or errors.

Advanced Techniques

With adult supervision at a makerspace or school lab, run your design on a real CNC machine. This will probably be a small desktop router like an X-Carve or Shapeoko. Before the machine turns on, walk through the safety checklist: Are clamps tight? Is the bit secured? Is everyone wearing safety glasses? Is the cut area clear? Watch the first pass carefully — listen for any unusual sounds. After the cut, examine your piece: is the depth correct? Are edges clean? Document three things that worked and one thing you'd change in your notebook. Take a photo of your finished piece. You're ready for the next step when you have a physical CNC-cut piece you made yourself and can describe one design change that would improve it.

Final Project Showcase

Design and cut a more complex project that solves a real problem or creates something meaningful. Ideas: a custom phone stand, a puzzle with interlocking pieces, a sign for your bedroom door, or a Utah state outline with your city marked. Use Inkscape (free at inkscape.org) to design your vector file — it gives you way more control than Easel alone. Import your SVG into Easel or Carbide Create (free at carbide3d.com/carbidecreate) to generate tool paths. Cut your project, photograph the process from design to finished piece, and write a brief maker's log: design decisions, settings used, problems solved. Share your project and log on Instructables.com so other young makers can learn from your process. You're ready for the next step when your finished piece is posted publicly and someone outside your household has commented on or asked about your project.