Rapid Fabrication of Disposable Fixtures for Correct Assembly of Split Build Rapid Prototyped Parts

The size of part that can be produced in a single build on any ofthe commercially available Rapid Prototyping systems is limited by the size ofthe particular machine's build envelope. Parts which exceed the dimensions ofthe build envelope are split into sections that fit the machine's envelope and these sections are fabricated separately. Assembly ofthe sections into an accurate three dimensional object often requires the creation of a fixture. This fixture ensures correct positional and angular orientation ofthe sections during assembly. This paper discusses the fabrication ofsuch fixtures using Shapemaker II, a Solid Freeform Fabrication process developed at the University ofUtah. Using Shapemaker II, large fixtures (4 ft. by 8 ft. or even larger) can be created in just a few hours. While the fixture is reusable, given the low cost ofthe fixture, it can be considered a throwaway item.