Knob for Makerfarm Prusa i3v with graphical display

I slightly slightly modified the knob design by BigBadBison (http://www.thingiverse.com/thing:391464). The hole was too deep for my Makerfarm prusa i3v so I brought the inside lip flush with the surface so the knob doesn't go as deep. I also added a small hole for a grub screw to tighten the knob in place as it fit well, but was just a little to loose. Now, just insert a small grub screw and tighten it down and it holds tight.