The CraftBot is an excellent piece of hardware. One of the few weak points in the design is the stiff yet flimsy little nylon nut used to hold the build plate in place. I lost a large print once when the vibrations made the nuts come loose, and the plate actually fell out of the machine during the print. This modification consists of a larger knob printed in flex material, with the old nut inside. It holds the plate with a firmer grip. Edit: Also see http://www.thingiverse.com/thing:609874 which is a bit slimmer and takes a metal M4 nut.Print in flexible material, stick the old nut inside and attach under the build plate.