This is specially designed to fit case-rap: http://www.thingiverse.com/thing:671209 And it also holds in place the back pannel. Here is the new video of assembling/disassembling the case-rap whith this spool holder. http://youtu.be/aMwy9CzHdEc You'll need a m8 rod and 2 nuts. Cut it as long as possible, it is easyer to fix in place. I had a lot left from my old prusa i2, that I just transformed into a case-rap!