Introduction

Rapid prototyping is the production of an item using an additive manufacturing technology. Where subtractive manufacturing generally takes a large piece of a material and carves out a part, additive manufacturing instead builds up a part by adding thin layers on at a time to form the part. 3-D printing is a widely known additive manufacturing technology.

The following image is a part created by ShapeWays , which will be discussed later on. This is to demonstrate the part complexity possible using additive over subtractive manufacturing. It would be exceedingly difficult to fabricate such a part either by hand using machine shop tools or using CNC (computer numercial control) machines.

Part created using Shapeways service

Rapid Prototyping at RPI

Luckily for us, RPI has resources on campus for rapid prototyping. To use the 3-D printing service, one must create the part using CAD software and submit the part file to *this form*. That webpage also has a price calculator used to predict what the total cost of the part will be. The accepted format is .STL and most CAD programs will output this file type with no issue. There is a disclaimer on the part submission that says that all mainstream CAD programs will work, but that some 3D modeling programs such as Rhino will output corrupted STL files.

There are two different machines that can be used for rapid prototyping, with one printing parts made of ABS and another that uses starch powder cured with either superglue or wax. The pros and cons of these two approaches are seen on *this page*. The turnover for all parts at RPI is typically between 1-2 weeks.

Rapid Prototyping Using Shapeways

For some projects, it's possible that another material might be needed than the ones available through the RPI manufacturing network. Another option is using an online vendor for 3-D printed parts, one of which is ShapeWays . ShapeWays currently has 11 types of materials for use in rapid prototyping, including metals, plastics, and glass, which can be see *here*. The website includes full instructions for creating and submitting parts, along with more information relating to their manufacturing process. Not every part can be made with every material, and the lead time for various materials differs. Yet again, all of that information is stated pretty clearly on the website.

Other Campus Resources

In addition to 3D printing, the RPI engineering department also has several CNC machines, and other fabrication tools that take CAD parts, such as a waterjet cutter.

-- CihanCaglayan - 2011-08-31