Direct digital manufacturing

What is Direct Digital Manufacturing ?

Direct digital manufacturing is a relatively new manufacturing process which manifests physical parts directly from 3D CAD files or data using additive fabrication techniques, also called 3D printing or Rapid Prototyping. The 3D printed part or parts are intended to be used as the final product itself with minimal post-processin.

What is Additive Manufacturing ?

Additive Manufacturing is also referred to as Additive Freeform Fabrication, Rapid Prototyping, Layered manufacturing or 3D printing. The technique physically constructs or manifests 3D geometries directly from 3D CAD. The history of the process spans approximately 25 years. It was originally known as Rapid Prototyping because the technology was used to make prototypes of parts without having to invest the time or resources to develop tooling or other traditional methods. Since the process was slow, it was used solely for prototyping and the name rapid prototyping became the common term use to describe the process.

Additive Manufacturing and or Direct Digital Manufacturing is a logical extension of the process. In the past 10 years the machines have become practical both in cost and speed. They have become both reliable and economical to use. This has led to the expansion of the technologies use in industry and an explosive growth in the sales and distribution of the hardware and the emergence of a new industry for better software tools to make more effective use of the technology. Even the materials that the machines are capable of utilizing has seen an explosive growth in the past decade. Modern machines can utilize a braod array of plastics & metals.

As the speed, reliability and accuracy of the hardware improves, the potential exists for additive manufacturing to replace or compliment traditional manufacturing as a menas to produce end use products and eventually the potential for complete elimination on the reliance of traditional manufacturing. In fact; much of the labor associated with traditional manufacturing is also eliminated.

The practicality of the technology for widespread use is, according to many experts, on the verge of a paradigm shift. In 2007 a sub $4,000 machine was presented. The price and throughput continues to drive appeal in the market but the deployment technique is akin to traditional small machine shops as 3D printing bureaus have sprung up around the globe. New deployment models and uses will only help to expand the presence of the technology in the manufacturing industry.

The logical conlusion that can be drawn from the technologies advantages are include but are not limited to;

1.) energey efficiency: 3D printing is highly energy efficient itself. Only the energy necessary to form the part is necessary and excess waste is eliminated. This can be demonstrated by the concept of machining. In traditional machining, energy is used to smelt metal into ingots which become billet materials. These billet materials are then machined, removing a great deal of the material to end up with a final part. The energy used to create the originbal block of material was effectively wasted.

2.) Low waste: Since the process only forms the desired part, there is almost no waste formed. Unlike traditional machining, the amount of scrap material created is almost non-existant. This fact ties in with the energy efficiency concept. Sicne there is no waste by product, there is also no energy need to transport the waste or dispose of it.

Technologies

There are presently about 25 3D printing technologies. The oldest is LOM or Layered Object Manufacturing. The next oldest is Stereo Lithography. More recent technologies include SLS or Selective Laser Sintering, Jetted Model technologies (similar to an Inkjet), FDM or fused deposition modeling and many variations. All of these technologies take a 3D data file from a computer, slice it into layers or cross-sections and then use each cross section to build a product in a layered fashion by printing each layer one at a time on top of each other until the final geometry is manifested.

An easy way to think of how the technology works is to consider taking an object and placing it on a meat slicing machine. Set the slicer to the finest setting and begin slicing the part. The slices represent layers that when re-combined effectively reproduce the part. 3D printing takes a 3D model, slices it into layers in a computer and then send each layer to a 3D printer whcih prints successive layers until the product is effectively manifested as intended. Varying the layer thickness affects the model surface finish and many methods have been devised to improve surface finishes whcih are historically a tradeoff between speed; which is a direct function of layer thickness and print speed).

Is Anyone using Direct Digital Manufacturing yet ?

There are presently around 50 commercially viewable examples of 3D printing being used for tooling or intermediate parts. The technology is still in its infancy and the use is directly dependant on someones knowledge of engineering to design a part and effectively use the printing equipment thus; the growth of the market is, although fast at 33% annually or better according to Terry Wholers, still very slow compared to where it can be.

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Future

The future of DDM is interesting. There are speculations that DDM will eliminate traditional manufacturing and that entire products as complex as a computer can eventually be printed. An alternative use of the technology is mass-customization. One company is leading the way of integrating the key technologies of 3D printing, the internet and Computer aided design is Digital Reality, Inc. a Technology startup company based in Austin Texas. Their premise is to let consumers design their own products in an intuitive manner since consumers 1.) don't want to start from scratch to design their own product and 2.) Don;t know CAD software or engineering well enough to design their own products.