This bracket was created in order to mount a stepper motor on glass for the creation of a Polargraph drawing robot. In order to mount the bracket to glass, you will need a Harbor Freight quick-release suction cup to modify. Item#46900 1) Remove the rubber cup and spring from the Harbor Freight cup. 2) Download and print the modified lever-handle and use the existing hardware to attach the cup to the bracket. http://www.thingiverse.com/thing:879840 3) Using 4 screws, attach the stepper motor to the bracket. Print must be supported. Layer height varies depending on print quality desired. Download and print the modified lever-handle and use the existing hardware to attach the cup to the bracket. http://www.thingiverse.com/thing:879840 Layer Height .25mm Infill 30% The design of the Polargraph was created by daGHIZmo. http://www.thingiverse.com/thing:798076