CNC- Computer Numerically Controlled Milling.

 

Usually, when I’m sculpting, either life-size or monumental, I create something small and 3D scan it to get a 3D model. I can also create something in the computer for a 3D model. We had a couple of strikes against us in the studio with this project. First, one of my main vendors shut down their CNC shop during covid. The other is that all the other vendors are way behind on their projects and using them is cost-prohibitive. 

These vendors use CNC or computer-numerically controlled milling to carve out my sculpture in foam. There are two types of foam; one is polystyrene - which they make coffee cups. You know, the tiny white beads all stuck together? The other foam is urethane foam. Each foam has its drawbacks. Polystyrene does not carve well, but it is safer to work with unless you should accidentally put a torch to it or spray paint it. It melts and has dangerous fumes. Urethane foam carves like butter, but you must wear a mask when you carve on urethane foam as it is dusty, and you don’t ever want it to get caught in your eye. Urethane is very, very expensive. It comes in different densities. For example, some you can get that are as hard as wood. We typically work with a less dense urethane, and it is my favorite foam.  

ARMATURE AND CLAY 

The foam becomes an armature. An armature is a solid structure that holds your clay. This may be a good time to talk about clay. I sculpt in many different types of clay. The one you are most familiar with is a water-based earth clay that you fire in a kiln. You could not use this type of armature with that water-based clay because when you use that type of clay, you have to keep it wet, and it needs something on which it can grab hold. I use clay that I heat up in crockpots and then hardens when it is on. It can stay on an armature for a long time, making it a good clay to use when doing commissions. 

 Before having the technology of CNC, I used to weld all my armatures. Sometimes, if you were using this clay before CNC, I would use spray foam insulation and then carve that away to get a basic shape. CNC saves me lots of time.  

Because of COVID, we were scrambling for a CNC armature, and a friend could slip mine in with his jobs, but it had to be carved in polystyrene. Remember, that is the styrofoam cup type of foam that I do not like. But I was thankful to have any armature. 

Here is a video of the carving of the digital technology I used to sculpt the Alice sculpture. Watch at 2:07 in the video, and you will see the March Hare that my vendor cut out of the foam. 

Being able to scan a sculpture and make it large or create it in the computer and make it large using cnc saves me a lot of time. Before this, an artist would have to measure one point on a more miniature sculpture, translating that into a larger sculpture. I mention this in my book.  

For Teachers and Students

Have you ever tried to create something larger from a smaller version?  
Here is an old machine from a person Achille Collas who lived (1795–1859) Collas was an  engineer, inventor, writer and engraver.  Of course when you need something that is how you usually come up with creative ideas and he needed to make small things big and big things small so he created a way to  mechanically create engravings and copy sculptures. In french  it is called réduction méchanique", and his invention played a big part in the bronze industry.

A pantograph is another way to make small things big . Here is a video on how to make your own pantograph. There are more plans on the internet.