Hi, On this page http://wiki.e3d-online.com/wiki/BigBox_Printer_Sub-assemblies I'm just finishing the Dual Extruder assembly. All fine except I'm not sure if the Bowden coupling should sit IN the hole at the top of the assembly OR be pushed INTO the hole? (which would require a little force). The coupling has small metal tags on the circumference, which I guess would bend to allow it to fit in the hole as opposed to on top. It is also possible that the doughnut piece is fitted IN the hole FIRST and then the internal part is pushed into place to hold it there?