CNC-Milling the human headSeptember 2012
In 2011 I was commissioned to create a bust of a local politician. He is well known in my area and so it wasn’t that difficult to find some reference images. The goal was to create a watertight sculpture that can be 3d printed and milled later on. So I started with one of my solid base meshes and blocked out basic proportions. As soon as I was happy with the overall form and distribution of the main shapes, I concentrated on the profile. One of my modeling teachers told me once: create the profile first, create it once and make it look right! Only then you are good to go with the other views! At that time I was attending a pretty famous wood carving school here in North Italy. I worked on a copy of Gian Lorenzo Bernini’s “Constanza Bonarelli” and decided to use the form of the base of this wonderful sculpture also for the bust. A solid base structure is important when you use quite heavy material like cherrywood or nutwood.
3DWood GmbH (www.3dwood.com), the company who did the milling and finishing wanted to make a small 3d print first, to check if the head still works as a real object. To rely on how a 3d model looks in the viewport is still critical on subjects like this. It’s totally OK when you deal with geometrical stuff and objects that have clear dimensioning – usually what you see is what you get, or better, what you measure is what you get. It’s different on organic sculptures that should be still recognizable at the end. As you know, you can change the focal length in ZBrush for instance. Or enable and disable the “align to object” function or turn off perspective completely. All this changes the appearance of the model on screen. So we passed it on to another local institution that has a Zcorp ZPrinter 650. People there prepared it for printing, gave it a wall thickness of 2 millimeters, perforated it at the bottom to remove the remaining powder and printed out a copy in sandstone – and it looked great!
Finally the 3DWood guys imported the STL file into their CAM software and prepared it for milling with a KUKA robot. Watch the video to get an idea of how the milling works! You could call the model pretty much finished the way it came out of the machine. Only some small details got lost during the production and were added by hand from a wood carver of their workshop. At the end they added a special finish to make the surface super smooth and shiny. What a great project!
Shapeways, they offer one of the best online printing services.