Page 1 | 2 » Customized manufacturing — it seems like an oxymoron, since manufacturing usually generates thousands of identical parts, yet it perfectly describes a growing approach to creating just what the market demands today. Back in the early 1900s, when Henry Ford offered his cars in any color as long as it was black, he did so with good reason. His assembly lines ran quickly and smoothly working with just one set of auto-body parts. However, today’s customer has raised the expectations bar on products ranging from surgical implants to custom shoe inserts. Rapid manufacturing technologies offer very attractive solutions to optimize the economics of such challenges. In this article DE explores a range of applications well under way in both customized manufacturing and mass customization. The former term refers to a cost-effective approach to generating a family of very similar products. Each one is based on a common design, which is then produced in hundreds or thousands, e.g., artificial hip joints in a dozen sizes. Mass customization describes the newer business model of creating many parts simultaneously or in quick succession, where each unit is completely unique but is defined by a sequence of consumer-tailored choices, e.g., online ordering of custom game figurines.  | The Right Fits for Medical Uses
One very successful custom manufacturing application is the direct-metal production of fully certified dental copings, i.e., the metal base of an actual tooth crown subsequently coated for final use. Rapid Quality Manufacturing (RQM) creates such parts from cobalt chrome metal powders on EOS’ laser-sintering equipment. Manufactured in batches of several hundred, the copings are customized to suit individual patients — no two pieces are exactly alike. Production of each dental coping starts with a scan of either a dental impression of the teeth or, more recently, a scan of the patient’s actual teeth (this newer process is called Chair Side Oral Scanning; see August 2007 DE). This electronic data is sent to a dental lab where technicians review and clean the models and make any necessary adjustments. The lab then sends the revised file to a supplier such as RQM, which laser-sinters the metal substructure. The cobalt chrome material, medically certified for actual end use, serves as a base on which the dental lab applies a final porcelain coating prior to its being cemented in the patient’s mouth. The result is a fast, cost-effective, high-quality crown. As anyone who has had one done will agree, a great fit without lots of in-chair rework is a welcome achievement. Each EOS machine can produce 200-300 copings a day. RQM is currently producing crowns and bridges for its partner, Quantum Technologies of Windsor Canada, and has targeted full-scale production with a second customer for late 2008. Servicing both the dental and hearing-aid industries is In’Tech Industries of Ramsey, MN, operators of a fleet of high-end 3D Systems’ SLA Viper equipment. The company produces such high-resolution parts as fully custom earmolds for hearing aids and patterns for a range of dental end-applications. Keep Up with Manufacturing Activity
• To understand the growing level of activity in the custom manufacturing world, check out the e-newsletter The Additive Fabrication Spy compiled by Castle Island’s Ed Grenda. Known for his Worldwide Guide to Rapid Prototyping website and publications, Grenda tracks patent applications in relevant areas and provides regular e-mail updates.
• Terry Wohlers continues his extensive tracking of absolutely everything RP&M at his website. And you may also want to subscribe to the RM-Platform, the online discussion forum of The European Collaboration on Rapid Manufacturing, for case studies, news, and events. | In’Tech regularly manufactures anywhere from a hundred to a thousand parts per day just for its hearing-aid clients alone. They have the capability to work from clients’ scan data, or do their own laser scanning of silicon impressions, then build the actual parts from biocompatible medical materials in clear, skin, and other colors. As large as the hearing-aid market seems (a few million per year in the U.S.), it is still dwarfed by business in the dental industry for the simple reason that the latter involves greater insurance coverage. Hence, In’Tech’s customers also include a large network of dental labs. Traditionally, after dentists took impressions of teeth, those labs cast the molds with plaster. The heavy physical models became the patterns for fitting various dental parts. Now, In’Tech scans the original impressions or receives direct scan data of teeth, then uses the data to drive its larger SLA Viper Pro machines. The large build volume accommodates rapid production of high-resolution epoxy-based models that include individual teeth, arch sections, and full arches, all on a high-volume basis. These models replace the traditional plaster versions for the actual dental lab work. Moving from head to toe, consider that few people would buy a pair of generic one-size-fits-all shoes; even flip-flops come in small, medium, and large. You definitely want the right fit when you need extra support to slip inside those shoes — known as a medically prescribed orthotic. Soletec Systems of Leicestershire, England, offers a full range of services for producing custom footwear and orthotics, and they have turned to rapid manufacturing to efficiently create the best fit.  | From Orthotics to Implants
The company installs MicroScribe scanning equipment from Immersion at the offices of medical professionals and trains them on its use. For an orthotic, first a simple procedure automatically captures seven different data points on a patient’s foot. Soletec’s custom software then takes this information and creates a CAD model of the desired corrective orthotic form (a slim, removable insert that sits on the insole of a shoe). Lastly, the CAD geometry file is sent electronically to a service bureau where the unique orthotic is produced on a CNC machine from medical-grade polypropylene or nylon acetate. This direct approach eliminates the traditional need for making a rather messy plaster cast of a patient’s foot. The cast had to be delivered to a service bureau to be used as a mold for forming the actual part. Soletec Systems’ solution does away with the molding step, saves up to two weeks over the traditional shipping and manufacturing time, and produces finished pieces that rarely require any modifications. When it comes to delicate surgeries, even more is at stake to do the best possible job the first time. Arcam’s Electron Beam Melting (EBM) systems are the source behind the production of just-right CE-certified joint-replacement products from Adler Ortho Group, an Italian manufacturer of orthopaedic implants. Several years ago, Adler Ortho developed a new design for a titanium acetabular cup as part of a hip-replacement surgical configuration. The product name comes from acetabulum, the cup-shaped socket of the hip joint which is a key feature of the pelvis. The head (upper end) of a femur (thigh bone) fits into the acetabulum and articulates with it, forming a ball-and-socket joint. Key to a successful surgery, termed “fit and forget,” is the implant’s ability to attach itself to the hosting bone. Adler Ortho chose EBM technology to produce implants with full material properties formed in a lattice structure for improved osteointegration (bone growth into the part). The choice of material was Ti6A14V, and the final design is a lattice with spaces of about 700 microns throughout the outer surface. Bone growth occurs by attaching itself directly to the metal without any fiber tissue involved. During its first year on the market, more than 1,000 cups of various sizes were successfully implanted, and production is ramping up. For certain situations, surgical implants involving actual bone material can offer the best chances for success. AlloSource, one the nation’s largest nonprofit bone and tissue providers, fills this need by shaping custom spinal implants from actual femur bone material. Their systems of choice are MDX-540 desktop milling machines from Roland DGA. The precision results are so good that the provider produces anywhere from several hundred to close to a thousand implants per week. The implants, custom fit for each patient, are used in spine-fusion surgeries and look like flat, oval disks. To drive production, AlloSource creates the designs from a mix of physician-input, anatomical restrictions, and technician know-how. Lumbar grafts tend to be made in five or six sizes (heights) in 2mm increments; cervical grafts can have eight or nine heights usually 1mm apart. Roland’s Rapid Custom Manufacturing (RCM) technology makes fast work of milling exact shapes, producing spinal implants with an optimal cross-section for each patient. This approach offers a major improvement over traditional clinical processes for mass-producing one-size-fits-all parts, or tediously hand-sculpting unique versions. Page 1 | 2 »
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