Stereolithography
While stereolithography is one of many rapid prototyping processes used to fabricate 3-D objects, we feel it has the broadest range of applications, from precision patterns to high quality appearance models. It's an amazingly rapid and accurate way to transform your data into a three-dimensional object. However, as instantaneous as the process may seem, there is a high level of human intervention that must take place.

• Simply put it is a method of rapid prototyping which converts 3-D CAD data into a series of very thin slices or cross sections and uses a laser-generated ultraviolet light beam to trace each layer onto the surface of a vat of liquid polymer, As the laser hits the photopolymer it is catalyzed, subsequently forming, hardening and bonding each layer until the complete, full-size prototype is formed.
  
  
• Nearly any geometry imaginable can be created with this "additive" process including closed or trapped volumes such as bottles. An advantage over machining is that there are no additional set-ups required to form the "underside" of the part and no radius allowance is required for square corners. Additionally parts of limitless size can be created with a high degree of accuracy. The most common platform size is 20 by 20 by 22 inches deep. Moeller Design takes great care in the maintenance and calibration of our equipment. Subsequently, tolerances are well within standard engineering conventions.
  
  
• The primary considerations to cost are part material volume and Z height or number of layers which directly relates to the laser run time. Wide variations in part pricing can be encountered particularly when dealing with commodity providers of SL parts, due to the practice of using heavy slice layers, i.e. .006 or more. This reduces the "draw time" but generates a highly faceted surface requiring additional hand clean up and the loss of accuracy.
  
  
• Moeller Design examines every file and quotes the appropriate layer thickness based on geometry, build orientation and intended use. We most commonly use a .004 layer thickness for optimum price to accuracy. Don’t be fooled by provider’s claims of "High Definition" stereolithography as a proprietary process. Layer thickness down to .002 is achievable with state of the art equipment and may be the appropriate choice for your SL part.
  
  
• Limitations of stereolithography are primarily related to materials, although the resins available today are far superior to products available only a few years ago. More at SL Materials. "Precision" accuracies found in tight tolerance machining can be achieved through second operations.