i3 Large Spool Holder for M8 Threaded Rods

Update October 28, 2017: New design, also good as single arm version. Three types for different usages, all parts are interchangeable (same measures). The Single Strong version is good enough to hold 2.2kg Eco-Rolls (the black filament on the pictures), but you can also try the 'normal' single version, or the often seen thin (double) arms. Clicks in well on the frame, push back the buttom-lid to release!

This is my version of a spool-holder on the i3 MK2 frame. Longer so that bigger filament-