If you only want to print the apparatus, you only need the following files provided in the STL folder.
(1) The physical dimensions of Frame.STL exceed the capacity of most low-end printers.
(2) For the Lulzbolt printer, you can use TwoFramePartsToPrint.stl, which breaks Frame.STL into two parts and arranges them into a compact configuration.
(*) For the MakerBot printer, there is a different solution "in the works". News soon.
Load them into a program such as Cura (free), which will produce a “G-code” file for your particular 3D printer.
The source files ( .SLDPRT and .SLDASM ) are proprietary formats for the SolidWorks software suite. If you do not have a SolidWorks license ( it is not free ), you can open these files with the free program eDrawings. This program allows you to view them, and export them as STL files.
Frame - 1 (2-Parter).SLDPRT
Frame - 2 (2-Parter).SLDPRT
(*) All 3D-print files available through an open-source license