3D Carving for Beginners: Your First Relief Project

What Is 3D Relief Carving?

If you’ve been doing 2D profiling (cutting shapes out of flat stock) or V-carving (engraving text and designs), 3D carving is the next step up. And honestly, it’s not as big a leap as you’d think.

With 2D work, your bit moves at a fixed depth. Cut this shape at 0.25” deep, done. With V-carving, the bit plunges to varying depths based on the width of the design. Both are essentially 2D operations.

3D relief carving is different. The machine moves in all three axes simultaneously, carving varying depths across the entire surface to create a sculpted, three-dimensional shape from a flat board. Think carved wooden signs, topographic maps, animal portraits, decorative panels. The bit traces back and forth across the surface thousands of times, each pass slightly offset from the last, gradually sculpting the relief.

The cool part? Your CNC already knows how to do this. We just need the right bit, the right file, and software that can generate 3D toolpaths.

What You Need

The barrier to entry here is surprisingly low. You probably have most of what you need already.

Ball Nose Bit

This is the one thing you might need to buy. A ball nose end mill has a rounded tip (instead of flat), which lets it carve smooth, curved surfaces. For your first project, grab these two:

• 1/4” flat end mill for roughing (removing bulk material fast). You probably already have one.
• 1/8” ball nose for the finishing pass (smooth detail work). Around $5–10.

We cover bit selection in more detail in our beginner’s bit guide. For 3D work, two-flute carbide ball nose bits are the standard.

Wood

Hardwoods give the best results for relief carving. Walnut, cherry, and maple all carve beautifully and hold fine detail. The tight grain structure means cleaner surfaces with less tearout.

That said, don’t waste nice hardwood on your first attempt. Use MDF for test runs (cheap, consistent, no grain to fight). Soft pine works for practice too, but expect some fuzziness on the carved surface.

A board that’s 6” x 6” x 3/4” is a great starting size. Big enough to see detail, small enough to finish in a reasonable time.

CAM Software with 3D Support

Not all CNC software handles 3D toolpaths. Your basic G-code sender won’t cut it here. You need CAM software that can read a 3D model or heightmap and generate the back-and-forth toolpaths for roughing and finishing.

We’ll cover the specific options in a moment, but the short version: Kiri:Moto is free and works great. VCarve Desktop ($350) and Carveco Maker ($15/mo) are the popular paid options. Our free CNC software guide has a full breakdown.

A 3D Model or Heightmap

You need a file that tells the software what shape to carve. This can be an STL file (the same format used for 3D printing) or a heightmap, which is a grayscale image where brightness equals height. White areas are the highest points, black areas are the deepest cuts.

Heightmaps are the easiest to work with when you’re starting out. More on where to find them below.

Where to Get 3D Models

You don’t need to be a 3D artist. There are tons of ready-to-carve files available.

Heightmaps are the simplest option. They’re just PNG or JPEG images in grayscale. You can find free heightmaps all over the internet, and we maintain a free models library with CNC-ready heightmaps you can download and carve today.

STL files from sites like Thingiverse and Cults3D work great too. Search for “relief” or “CNC carving” to find models designed for this purpose. Just check the license before selling anything you carve from someone else’s model.

Kiri:Moto has a neat feature that converts regular photos into heightmaps. It’s not perfect, but it’s free and fun to experiment with. Upload a photo, tweak the contrast, and you get a carveable heightmap.

MakerWorld’s MakerLab has a relief tool that can generate 3D relief models from images. Worth checking out for quick projects.

You can also create your own models in Blender, ZBrush, or similar tools. But let’s be honest: learning 3D sculpting software is its own rabbit hole. Save that for later. Start with existing files and get comfortable with the carving process first.

Software Walkthrough

Let’s talk about how to actually turn a file into G-code your machine can run.

The Free Path: Kiri:Moto

Kiri:Moto is a browser-based CAM tool that handles 3D carving surprisingly well. No installation needed. Here’s the basic workflow:

1. Open Kiri:Moto in your browser and switch to CNC mode.
2. Import your heightmap (drag and drop works) or load an STL file.
3. Set your stock dimensions to match your actual board.
4. Add a roughing operation with your 1/4” ball nose. Set stepover to about 40–50%.
5. Add a finishing operation with your 1/8” ball nose. Set stepover to 10%.
6. Preview the toolpaths. Check that nothing looks wrong.
7. Export the G-code for your machine’s controller (GRBL, Marlin, etc.).

It’s that straightforward. The interface takes a few minutes to figure out, but there are solid YouTube tutorials linked in our sources below.

The Paid Path: VCarve or Carveco

VCarve Desktop ($350 one-time) is probably the most popular CNC software in the hobbyist world. Its 3D carving workflow is polished: import a model or heightmap, define your roughing and finishing toolpaths, preview, export. The built-in toolpath simulator shows you exactly what the finished piece will look like.

Carveco Maker ($15/month) offers similar 3D functionality with a subscription model. If you don’t want to drop $350 upfront, this is a solid alternative. Carveco also has more advanced relief editing tools if you want to combine multiple models into a single design.

Fusion 360

If you already use Fusion 360 for other CNC work, it handles 3D toolpaths through its Manufacturing workspace. The “Parallel” and “Scallop” finishing strategies work well for relief carving. But if you’re not already in the Fusion ecosystem, the learning curve is steep for this one task. We wouldn’t recommend starting here just for 3D carving.

For a deeper comparison of all these options, check our software guide.

Your First 3D Carve: Step by Step

Alright, let’s actually make something. Here’s the process from start to finish.

1. Pick a simple model. For your first carve, choose something with a single subject and clean shapes. A topographic map, a simple animal silhouette in relief, or a geometric pattern. Avoid tiny details on your first go. Check our models library for beginner-friendly options.

2. Set up your stock. Grab a flat board, measure its thickness (you’ll need this in the software), and secure it to your wasteboard. Double-sided tape works for smaller pieces. Clamps or screws for larger ones. This is important: 3D carves run for a long time, and any movement during the job ruins everything.

3. Import and configure in your CAM software. Load the heightmap or STL. Set the stock dimensions to match your actual board. Set the model height (how deep the relief should be). For a 3/4” board, a relief depth of 0.3” to 0.5” works well.

4. Generate the roughing pass. Use your 1/4” flat end mill with a 40–50% stepover. This pass removes the bulk of the material quickly. It won’t look pretty, and that’s fine.

5. Generate the finishing pass. Switch to your 1/8” ball nose with a 10% stepover. This is the pass that creates the smooth, detailed surface. It takes longer, but this is where the magic happens.

6. Set your feeds and speeds. We cover this in detail in the next section. For now, start conservative. Check our feeds and speeds calculator and our beginner’s guide to feeds and speeds for specific numbers.

7. Run it. Zero your machine, start the roughing pass, and watch. After roughing, run the finishing pass without moving your zero point. Watch as the detail emerges.

Feeds, Speeds, and Stepover for 3D Carving

3D carving introduces one parameter you probably haven’t thought much about yet: stepover.

Stepover is the distance between each pass of the bit. In a finishing operation, the ball nose traces back and forth across the surface. Stepover determines how far apart those lines are. Smaller stepover means more overlap between passes, which means a smoother surface. But it also means more passes and longer carve times.

Here’s the tradeoff:

• 10% stepover (finishing): Very smooth. Minimal visible ridges. Takes a while.
• 20% stepover (decent finish): Slightly faster, very slight ridges that sand out easily.
• 40–50% stepover (roughing): Fast material removal, rough surface. That’s the whole point.

Finishing Your 3D Carve

The carve is done. It looks good off the machine, but the finishing step is where it goes from “cool CNC project” to “wait, you made that?”

Sanding. Go gentle. You want to smooth the surface without flattening the relief. Use 150 or 180 grit to knock down any fuzz or ridges, then follow with 220. A small piece of sandpaper wrapped around your finger works great for getting into curves and details. Don’t use a flat sanding block on a 3D surface. It will flatten your high points.

Apply a finish. Oil (Danish oil, tung oil, or even mineral oil) is the easiest and most forgiving finish for relief carvings. Brush or wipe it on, let it soak in, wipe off the excess. The transformation is dramatic. Grain pops, contrast deepens, and the whole piece looks like it came from an artisan’s workshop instead of a garage.

The before-and-after on a piece of walnut with a coat of Danish oil is genuinely stunning. We’ve seen people post their first 3D carve on Reddit and get hundreds of upvotes. It really does look that impressive.

Common Mistakes (and How to Avoid Them)

We’ve made all of these so you don’t have to.

Stepover too large on the finishing pass. If you see visible ridges or “corduroy” lines on your finished piece, your stepover is too big. Drop it to 10% or even 8%. Yes, the carve takes longer. It’s worth it.

Skipping the roughing pass. Running your tiny ball nose bit through solid material to full depth is asking for trouble. The roughing pass with a larger bit clears the bulk material. The finishing bit should only be cleaning up what’s left. Skipping roughing puts way too much stress on the finishing bit and can snap it.

Using the wrong wood. Pine and other softwoods tear easily under a ball nose bit, leaving a fuzzy, rough surface. It’s usable for practice, but don’t judge 3D carving by a pine test piece. MDF carves cleanly and is great for dialing in your settings. Hardwood (walnut, cherry, maple) is where the real results come from.

Poor workholding. 3D carves can run for an hour or more. That’s a lot of vibration. If your piece shifts even slightly during the carve, the finishing pass won’t align with the roughing pass and you’ll get visible steps or artifacts. Use more hold-down than you think you need. If something goes wrong during a long carve, check our troubleshooting guide for help diagnosing the issue.

What to Carve Next

Once you’ve done your first relief, you’ll want to do more. Topographic maps of your favorite hiking spots make great wall art (and gifts). Animal portraits in hardwood look incredible. Company logos with 3D depth. Custom signs with relief elements behind the text.

The process is the same every time. Find a model, rough it, finish it, sand and oil. Each piece gets a little faster as you learn what settings work best on your machine.