Open Lab Day: every Tuesday between 11am and 7pm. Just sign up for an appointment online. Time slots start on the hour and last one hour. Using our machines (laser cutter, 3D printer, PCB mill, etc.) is free. You just pay for materials. Our current list of tools is at http://hci.rwth-aachen.de/fablab_tools.
Since 2016, we've been offering the six-month Fab Academy at our lab, another first in Germany.