Remix of a mount from tbadger61 on Thingiverse. I've updated the mount for gen 2 guide rails and a better attachment of the knob. Use a 10-24 x ¾" pan head machine screw and a 10-24 nylon lock nut for securing the knob. The hole diameter for the knob is sized at 5mm and the spacing for the nylon lock washer is 10mm if you need to use a metric screw and nut. Making the mount taller for the Gen2 rail added an artifact in the holes for the wall mounting screw and the knob screw, these are easily pushed out with a small pointy tool. 

Print with ironing on really helps the quality and the use of normal supports is recommended for the overhang.