Needed a mount for my filament spoolholder http://www.thingiverse.com/thing:1000323 and came up with this design. Edit: 8. september 2015: Added a mount based on the one without guide, with rounded top edges. Purely visual changes. Edit: 7. september 2015: Added a mount without the middle and sideguides. Do yourself a favor and make it 100% infill. Or at least high. I printed with 0,2mm layer height. The mount with middle and side guides might need support when printing. There is room for an M8 locking nut in the mounting piece, but I guess a normal M8 nut would work as well (since the normal type is smaller). BOM: 2x M8 locking nuts. OR 2x M8 normal nut. (I recommend locking nuts) Some 8mm threadded rod depending on your need. 2x M3 screws and 2x T-nuts to fix the mount to the 2020 extrusion Using these for Ultimaker 2 Aluminum Extrusion 3D printer: At least one of the mounts must be without guides, or there is not enough room for them.