M.S. Thesis Presentation by Brad David Geving
Monday, April 10, 2000

(Dr. Imme Ebert-Uphoff, advisor)

"Enhancement of Stereolithography Technology to Support Building Around Inserts"


Stereolithography (SL) is a method of rapidly prototyping parts and products by using a photopolymer resin cured by an ultraviolet laser layer by layer.  The ability to place foreign inserts such as motors, bearings, and joints into the prototypes during the build process would increase the functionality of the process.  To accomplish this ability, degrees of freedom need to be added to the current SL technology.

Currently the SL apparatus exhibits two degrees of freedom by scanning the laser beam on the horizontal vat surface and a third degree of freedom by moving the build platform vertically. One of the major problems with introducing a foreign insert is that doing so creates shadows on the vat surface where the laser cannot reach to cure the resin. To be effective in building around a foreign insert, degrees of freedom need to be added to change the angle of incidence of the laser beam on the vat surface and thus eliminate the shadows produced by the insert.

In this thesis, the development of a number of concepts for this purpose is discussed. One of these concepts is implemented in a test-bed that emulates the functionality of an enhanced SL machine. This test-bed is described and the kinematics that govern the test-bed along with their associated algorithms are derived. The kinematics are implemented in a software simulation to validate the functionality of the test-bed.