3D Printing

In the bad old days (in some places as much as a full decade ago), when designers designed a product or a part, they normally had to take the plans to a machinist to have a prototype made, to validate (e.g.) ergonomic data and fit between components.

In a digital age however, when design itself is now almost entirely digital everywhere around the world, it can and should quite simply be just the 'Print' button of one's computer that addresses this task. And indeed, this process of producing material objects from 3D Computer Aided Design is pretty widespread today and commonly known as Rapid Proto-Typing, or 'RPT'.

There have been earlier generations of RPT, but most, if not all, of the new systems are based on the idea of taking a computer 3D model and calculating paper-thin slices through it, so that the data represents a laminated model. This laminated-model data is then output layer-by-layer to the machine to solidify, fuse or cut material for each 'lamination' of the final output. The standard source is an 'STL' ("stereolithography") file, which is an output/export format now bundled with most CAD modeling packages available today.

It's all still very new of course, but many new technologies have already been run trough and are on offer. The first of these, generically called just stereolithography, used a vat of liquid polymer plastic, which was hardened in layers by intersecting lasers to create a solid plastic object. The liquid base-material for this was however very expensive and the process very slow. To cap that, the device needed to be located in an environmentally controlled room, adding up with everything else to a total cost and hassle of machine-ownership that was worthwhile for only just a few job-bureaus and research institutions.

Amongst other technologies that followed, generally offering faster and cheaper operation, one particular system (LOM) even works by laminating laser-cut sheets of paper together to derive the 3D output! Not surprisingly, each process generally has it's own advantages and disadvantages and several have evolved into specific market niches.

Expectedly, the ability of 3D printers to accelerate the processes of design and prototyping has made them attractive to manufacturers wanting to cut production costs while at the same time continuously riding the cutting-edge of product and parts design. Chrysler, for instance, uses this technology to make prototype automobile parts.

In general today, 3D printers operate much like ink-jet printers, depositing (e.g.) a plaster-based powder that hardens with a liquid binder into successive layers of the object in a process known as Fused Deposition Modeling (FDM). End products are not quite as durable or detailed as models produced by other RPT systems, but output is about 10 times faster (normally hours instead of days), learning is easy, and materials cost is 'low'.

With the Genisys Xs however, data in the STL file directs a nozzle extruding a thin stream of hot liquid polyester. The nozzle rapidly lays down crisscrossing layers of polyester extruded in beads 0.3302 mm (0.013 inches) wide at a rate of 101 mm (4 inches) per second in the horizontal directions, building the model in layers from the bottom up. Fully loaded, the printer holds five pounds of polyester base-material in little rectangular wafers, which are loaded into cassettes. Each cassette holds fifty wafers, and the machine holds ten such cassettes.

One of the many uses RPT is put to today is with assisting in various types of surgery. For example, solid models of a patient's skull can be created from CAT scan data (which is also in the form of lamination data or 'slices'). The 3D slice data is rendered into STL format and a replica of the patient's skull created with the 3D Printer. Surgeons can then use the model to plan surgery, working out exactly what needs to be done and have any required prosthetic parts made before the patient has to go under anesthetic or suffer preliminary exploratory surgery. Another similar use is in hip replacement surgery, where it allows the prosthetic parts to be accurately manufactured prior to surgery.

3D printers can also build exact replicas of missing bits of bone or tissue to construct molds for flesh-like prosthetics (e.g., in the case of a missing ear). In other cases, models are used directly in surgical procedures too, as (sometimes temporary) replacements for damaged or removed pieces of bone. It's reported that the use of such computer-built prosthetics cuts surgery time, including the number of operations required for a procedure by 30-50%.

Here are a couple of examples of standard 3D printers available today

Z406 3D Printer
The Z406 System is a premium 3D printer with the capability of printing in full-color, communicating important information about parts, including engineering data, labeling, highlighting and appearance simulation. Z Corporation, who makes it, offers a variety of materials for use with the Z406 System. You can use parts directly or infiltrate them to serve a wide range of modeling needs

Z400 3D Printer
The Z400 3D Printer is an entry-level concept modeling solution that delivers great models quickly and inexpensively. Z Corporation offers a variety of materials for use with the Z400 3D Printer. Beginning with two basic materials, a versatile and inexpensive starch-based powder and a high-definition plaster-based powder, users can add infiltrates to provide a wide range of modeling needs.


Now, here's an example of a desktop full-color 3D printer that represents the sort of stuff one can expect to hit high street stores very soon. This one in particular, has been independently developed by A.F. van der Geest (Email: spitstec@wxs.nl). A patent application is under process, and Buss Modeling Technology GmbH is all set to take up marketing and distribution. Here's what van der Geest says about it:

"Just like a printer converts a 2 dimensional image from the computer memory into a hardcopy, this machine converts a 3 dimensional shape in a computer memory into three dimensional model.

"Unlike other so called "rapid prototyping systems" this machine not only creates the shape, but also the colors of the model. The machine is very fast and need not cost very much.

This printer can be used for many applications like:

* models of buildings
* models of furniture
* models of industrial designs
* presenting data from medical imaging techniques
* models of toys
* models of humans (wax models)

"Initially this is a machine for the professional market. Designers and architects can use this machine to view and hold their newly designed products and discuss it with their customer. In the long run this three dimensional printer can become a consumer product.

"On the picture some products which are built with the printer are shown. The large Porsche (135 X 50 X 45 mm) was built in 40 minutes. The bicycle took only 7 minutes to build.

"The prototype 3D-printer the weights only 13kg and measures 455 X 440 X 290 mm. It can make objects up to the size of 200 X 150 X 100 mm."