This is a threaded rod holder made for Rack-Mount. I was able to buy an old Rack-Mount, It's in my opinion the best case for a 3d printer :) I use this threaded rod holder with the help of my spool holder that clip in the spool. See the video and photos. https://www.youtube.com/watch?v=lng9eZjR9RE&list=UUg0rSjryYrw6MFuhJREnz4w Since most Rack-Mount differ, the SCAD can be changed to the desired dimension. UPDATED 2014-12-22: SCAD file and STL as been updated due to a small bug. You need 5M screw of at least 10mm, ideally 12mm, mine is 25, I used what I got :) and 2 5MM washers.