chapter  7
40 Pages

Rapid Prototyping for Medical Devices

Overview ................................................................................................................ 128 Rapid Prototype Technology .................................................................................. 129 In-House RP versus Service Bureaus .................................................................... 132

RP Service Bureaus .......................................................................................... 132 Ofce-Based RP Machines ............................................................................... 133

Types of Available RP Technologies ..................................................................... 133 3D Systems: SLA® ............................................................................................ 133 Stereolithography Materials .............................................................................. 134 Sony: SCS™ ..................................................................................................... 135 3D Systems: SLS™ ........................................................................................... 136 Stratasys: FDM ................................................................................................. 136 Resolution and Surface Finish .......................................................................... 137 Solidscape ......................................................................................................... 138 LOM™ .............................................................................................................. 139 Z Corp.: Three-Dimensional Printing ............................................................... 139 Polyjet Objet™ Printer ..................................................................................... 140 DLP: Envisiontec® Perfactory™ ....................................................................... 141

Sintering and Direct Metal .................................................................................... 142 RP Applications in Product Design ....................................................................... 142 Computer Numerical Control ................................................................................ 143

Full-Size VMC CNC Machines ........................................................................ 146 Machinable Prototype Materials ........................................................................... 146 Rapid Tooling and Molding ................................................................................... 147 Which Technology Is Best? ................................................................................... 148 File Preparation ...................................................................................................... 148 Other File Formats ................................................................................................. 149 RP Cost-Saving Tips .............................................................................................. 150 Secondary Processes to RP Parts ........................................................................... 150

Painting ............................................................................................................. 150 Electroplating .................................................................................................... 150 Machining ......................................................................................................... 151 Threaded Inserts ............................................................................................... 151

Installing the Inserts ..................................................................................... 151

The past decade has seen an explosion of rapid prototyping (RP), rapid tooling, and reverse engineering (reverse modeling) technologies. All of these technologies have become more readily available, less expensive, and more exible and capable each year. RP has been widely available for less than 20 years. These technologies put exciting and unprecedented capabilities into the hands of the designer to develop, iterate, and manufacture products. In parallel with the growth of RP, computing power has grown by orders of magnitude and plummeted in price. Computer-aided design (CAD) applications that not so long ago required a $50,000 workstation running a proprietary operating system can now be run on a computer worth less than $5,000 and an inexpensive operating system (OS) with high-end graphics. Desktop replacement laptops are making this computing power portable. Affordable CAD solid modelers and high-speed Internet connections allow designers and engineers to work from any location and transmit les to in-house RP resources, or remote service bureaus, and to receive parts quickly via courier service.