For the past few years we have utilized several forms of rapid prototyping to explore new methods of creating form. At The Ohio State University ceramics program, we have a large Techno Isel CNC (computer numerically controlled) router and a Konica Minolta Vivid 910 3D scanner, a Z-Corp 510 3D printer and a soon-to-be-operational Epilog laser cutter. In an environment where research and development are crucial activities, we willingly embrace these new technologies in search of a balance between traditional craft and industrial practice.
Rapid prototyping describes the harnessing of three domains of advanced digital technologies: three-dimensional data acquisition, including MRI and 3D optical scanning; 3D form modeling and manipulation; and the realization of sculptural form through both additive and subtractive processes: rapid prototyping 3D printers and computer-controlled machining, respectively. The capabilities of these new prototyping technologies have made practical a discipline that takes advantage of the existing computing environments and builds on them to provide cutting-edge three-dimensional design capabilities. These are indispensable tools that extend and enhance an artist’s ability to visualize, create and communicate form and extend the relationship between the human touch and concept. As this technology continues to evolve the cost of the individual units will continue to drop, broadening the access further.
Presently, for less than $6000 one can purchase both a desktop 3D scanner and a small desktop CNC mill, software included. Outside of purchasing the hardware, there are many ways to access this technology. Most sign fabricators will have the equipment to mill or machine a model. For 3D printing, there are a variety of online services and local companies who specialize in 3D output that are typically willing to fit your smaller items into other larger jobs at a discounted price.
The auto industry uses a clay-based system of industrial sculpting techniques for the translation of data into form. With all the virtual platforms available to critique and visualize the designs, the auto industry still finds importance in being able to touch and stand next to a full-size clay model. However, to aid in the development of form, the industry uses a 3D scanning process to archive their clay models. This serves a purpose similar to the back button on a web browser, allowing for previous models to be brought back and reworked. Through the use of large mobile CNC milling machines, the previous or new digital models are literally carved away. The milling machine operates on x, y and z axes and a point graph system to translate data into form.
From a studio-based perspective, the machinable-clay system offers the most flexibility. By harnessing a system based on digital information, the flow of generating form can move in a back-and-forth, side-to-side manner. Unlike some of the laser sintering and 3D prototyping systems, which produce or print forms out of resin or plaster, the clay forms generated by the CNC miller retain the potential for further alteration and surface development. The emphasis on process-driven relationships reinforces the importance of touch in relation to concept.
This interaction produces nearly endless applications for conceptualizing and fabricating form. Form, in simplest terms, is a tool used to fashion reality; at the same time it is a tool for recognizing reality. The recognition of form is the prerequisite for the creation of new form. As a tool, this process will extend one’s ability to view, critique and develop form more expressively than is presently possible from a sketch or maquette. Moreover, this approach toward the evolution of form possesses the means to record a physical object’s history of emergence. With the introduction of new technologies into a studio setting, there will always be the first attempts to reproduce existing objects like a tea bowl, or digitize a head or nude torso. The challenge is to move beyond the novelty and delve into the vast possibilities.
The capabilities of this technology open new ways of considering an object in terms of raw material. The technology presents a working method that analyzes the relationship between an object and the process required to generate that object. These new technologies will interject questions about the ramifications of scale and authenticity, and strive to illustrate how the process of construction relates to the characteristics of form-a melding of the technological with the metaphorical. Using these technologies only furthers an inquiry into our current perceptions of cultural history and how those perceptions are formed.
In the Studio
To demonstrate how this process has entered our studio research, our recent experiments have been in collaboration with the Sächsische Porzellan-Manufaktur in Dresden, Germany. During the summer of 2008, we had the fortunate opportunity to work at the factory and experiment with a small collection of their historic molds. Like Woody Allen in Zelig or Tom Hanks in Forrest Gump, this process allowed us to insert our new form into the historic context. These new prototyping techniques permitted us to interact with the classic forms from two vantage points-during the making of the porcelain objects and after the objects had been fired.
In preparation to work with the historic forms, we had been using the 3D scanner to capture a variety of taxidermy rodents and birds of prey. The object is positioned on a rotating table that turns in prescribed increments (30-45° between scans works best). The Konica Minolta has three different lenses-telephoto, midrange and wide angle. For the best detail, we used the telephoto lens, although this required scanning the objects from several different views and manually connecting the composites. Too many scans can actually generate redundant information and complicate the merging process. Invariably, the scanning process does not capture everything. Reflective surfaces, dark or black objects, transparent objects and, as with our models, hair and feathers, tend to refract the laser beam and fail to capture data. To address this, the objects can be coated or dusted with talcum powder or white make up.
With the scanning complete, we merged the data, then cleaned up and saved the digital file. The fun begins at this point, as the model can be scaled or manipulated in either direction. The model can be exported to a 3D printer or a laser sintering device, sent to 3D modeling software for further manipulation or combination with other digital models. With a 5-axis milling machine, it is even possible to have the object milled to any scale as a positive (model) or a negative (mold). In the case of the rat, we scaled the model to the largest size that the Z-Corp 510 could print as one piece. We later printed a smaller version to play with scale. The Z-Corp printer generates models that are made from a plaster-type material. However, the plaster prints are relatively fragile until they have been treated with a hardening solution. While the type of plaster used by the printer is not suitable for conventional ceramic molds, the positive prints do work well for generating plaster molds. We brought the mold of the scanned rat to the Sächsische factory.
Amazingly, the porcelain forms shrink at least 16% from their original mold forms. In the process of completing some of our experiments, the fired objects needed a base or additional component. To ensure an accurate fit with another object or material, we used the scanning process to acquire the necessary models. In the case of the porcelain dog on the pillow, a simple model was cast by filling a plastic bag with fluid plaster. The dog was nestled onto the bag while the plaster set up. Once hardened, the plaster cast was scanned to capture the formed indentation. Scaled up to account for the 16% shrinkage, the digital model was sent to a CNC milling machine, where a series of cutting paths were used to carve out a plaster mold. During this process, the form is first roughed out to remove the majority of the stock. Smaller cutting bits, used in decreasing size, refine the surface and develop the interlocking keys. From the resulting mold, a clay positive can be cast that will shrink to fit to the exact contour of the original porcelain dog.
Making and Meaning
The new tools of rapid prototyping enable fluid combinations of historic models with contemporary criticisms. As is the case of the auto industry’s reliance on tangible experience, these tools do not replace the problem solving skills of hand modeling. With any tool, there will be a learning curve; however, the underlying goal is to strengthen the discipline of developing form. We are interested in using construction formats that provide a layer of meaning toward the development of form. We are even more intrigued by how these primary shapes and images can affect us, physically and emotionally. The expressive, metaphorical and symbolic characteristics should strike a responsive cord, for there is a pull toward the heroic.
For great mold making techniques, be sure to download your free copy of Ceramic Mold Making Techniques: Tips for Making Plaster Molds and Slip Casting Clay, Volume II.
the author Steven Thurston is associate professor of art at The Ohio State University in Columbus, Ohio, and is a member of Non Fiction Design Collective (www.nonfictiondesigncollective.com).