Creating stunning wood carvings has never been easier than with a CNC router. Think of all the creative possibilities for milling: door panels, drawer lids, fascia boards, emblems, awards, artwork, signs, or your signature carved into the back of a project. The more you use your CNC router, the more projects you will find for it.
Not only does a CNC router add interest and beauty to your work, but just watching the machine dance around the workpiece, methodically and accurately creating beautiful carvings is a pleasure. A CNC milling machine can also be a tireless helper in the hand-carving workshop.
THREE ELEMENTS.
- There are many images on the Internet, especially on CNC sites.
So how do you begin carving wood on a CNC machine? There are three basic elements to consider: the artwork, the type of work, and the carving process. First, we need a digital image. You can create your own or find one online. You need specialized software to create a three-dimensional image suitable for carving. Vectric Aspire, Rhino and 3D Systems Geomagic Freeform are some of the many examples of software that can create 3D models suitable for carving on a CNC machine.
Creating files for milling requires CAM software that can handle 3D digital images. Once you have found a 3D image file and loaded it into your CAM software, the model can be scaled: enlarged or reduced, made deeper or shallower, narrowed or expanded, made taller or shorter to suit your requirements.
- Roughly milled workpiece on a CNC machine, ready for manual machining.
Carving on a CNC milling machine is usually done in high relief style. The carved area can be located below the surrounding surface as a pocket or recess, or it can be carved so that it rises above the surrounding surface. Another option is to create a carving that is cut from the source material and can then be attached to panels, architectural elements, etc.
The third step is to set parameters and create instructions for the CNC milling machine.
Milling a three-dimensional pattern is usually done in two steps. The first is rough cutting, which removes the bulk of the material, leaving a recognizable, low-resolution image. A straight spiral drill is suitable for this operation because it cuts and removes chips efficiently.
The second step is finishing, for which a cutter with a spherical end is used, as it is capable of making smooth, precise cuts. Depending on the size and level of detail of the threads, combinations of 1/4″ roughing and 1/4″ finish drill with spherical end, 1/4″ roughing and 1/8″ finish drill with spherical end, or 1/4″ roughing and 1/16″ finish drill with tapered spherical end are commonly used. For smaller jobs, a 1/8″ roughing drill bit might work, and a 1/32″ drill bit with a spherical end might work for finishing.
There’s more to it than just choosing a combination of cutters. The difference between excellent and average milling comes down to pitch and lateral speed parameters when setting up files for milling. Pitch is the distance between tool passes during the operation. The larger the pitch, the faster the cutting process, but less detail. A smaller step means longer process time, but higher detail. Generally, the roughing speed can be controlled with a maximum step and a side speed. Finishing cutting, however, requires some care to find the right balance between detail and production time. One last tip: when you go from rough cut to finish cut, don’t forget to zero the z-axis height!
- Going from roughing threads on a CNC machine to final, hand-carved threads makes each piece unique.
Time to confess: I’m a wood carver at heart and prefer hand tools, but I’ve found that a CNC router and band saw can be great helpers in preparing materials. Let’s say you need to cut a dozen top covers for wrapping Christmas presents. You can program the CNC milling machine to make only a rough design. After that, you will need to bring the carving to life in a way that the machine can’t, with crisp detailing and hand texturing.