Rapman Z drive sprocket pulley

This sprocket is referred to often and referenced to the Rapman Wiki. I put a copy up here in case something happens to the Wiki and the file goes away. It replaces part 10014 and the two stars above/below it. File's origin is here: http://www.bitsfrombytes.com/wiki/index.php?title=Spare_parts

The grub screw fell out of my acrylic Z drive sprocket. When reinstalling it, I heard a click... and noticed that the belt would lift up on the sprocket then fall down into the teeth. Tightening the gr