Silver's omnivorous fillament spool holder: rails and T-mount.

I decided to finally upgrade the fillament spool compartment of my LACK ensclosure, and i wanted to have as universal system as possible.

Asside from the great Wider and narrower remix spool holder, (that is of course a remix of a remix, coming back to Copanko) I also wanted an option for spools that need to be mounted by the central tube - for example those with paper sideplates, or basically any spool that is near empty and thus light/narrow enough to get pulled of the rollers by the extruder movement (it actually happened to me in one case and resulted in partially ruined print.)

The rails nicely stabilize the adjustable roller holders, while allowing movement along the X-axis, so you can position a spool to the nice center, while having another one ready just next to it - for that, I also reversed the adjustment screw.
Works best with the “slot” type fillament guide, I especially designed it for this, which is a remix of a design from ACE Krystal.

The “centre mount” part uses the injection-molded T-shaped holder that came with my MK3+ (fall 2021), I assume this is still the OEM part coming with new printers. You'll need some 5mm axis pin (I used a piece of threaded rod, an M5x50 screw would be the best, however).
When the original T-holder is not in use, it simply folds away to the back - you can use up to six  12x5x2mm magnets to give some fixation to both positions.

You can also use just just the rails without the OEM T-holder option: print two of the “front” rails, and take care about orientation - the “feet” of the adjustable holder are not symmetrical and i designed the rail to fit them.