We currently (2/24/18) have 4 3D printers in the 3D printing room in MS-L. They each have their own method for printing.
File Type: gCode - Marlin/Sprinter/RepRap
This printer has a Rasbperry Pi running OctoPrint attached to it. You access the printer by going to http://10.0.3.75. Once there you can follow the OctoPrint instructions.
File Type: gCode - Marlin
This printer uses the Repetier Print server at http://10.1.1.21 The login is makersmiths/makesomething2day
File Type: x3g - Makerbot/FlashPrint
This printer has a Rasbperry Pi running OctoPrint attached to it. You access the printer by going to http://10.0.3.75. Once there you can follow the OctoPrint instructions.
File Type: gCode - Marlin/RepRap
This printer is hardwired to the desktop printing station. The bed leveling is software based in their MatterControl software and is easier to use from there. You can also use Simplify3D (on loan from Sean Devine) which has a direct print button on it.