Use the OpenSCAD file and your own *logo.svg and *text.svg files to make your custom keychain bob. Purchase a “Key Chain Rings Kit” and attach your keychain bob. Search on “How to Wrap Text Around a Circle in Inkscape” for how to make the *text.svg file which is input into the OpenSCAD. 

The file “mhs 50th reunion keychain.3mf” uses the configuration of 2 extruders for a printer with only 1 extruder. The custom gcode to change extruders is the “M600” command to swap filament. This way the 3D printer will change filament color in the middle of a layer. The part 2 *.stl file contains the text for the back side of the keychain bob. The part 1 *.stl file contains the rest of the keychain bob.