Edit 06/04/2022: I had three-part instructions typed into Thingiverse back in 2018, and they were visible for a couple of years, but it seems that Thingiverse deleted my "Printing Settings" and "Post-Print" sections sometime in 2021. I found one of the assembly photos, and I've tried to re-create the "Print Settings" and "Post-Printing" sections. If anyone saved the original version as a .pdf, then please supply it to me so that I can more fully re-create the original sections.

This is a filament holder (or roller) that mounts to the top of a printer enclosure. It accommodates a large range of spool widths (45mm-155mm) and diameters (120mm-320mm). The center also stays in the same location through all the adjustments. I designed it because the spool holder that is included with the Ikea LACK Table enclosure from Prusa Research (https://www.thingiverse.com/thing:2864118) is a fixed width and I didn't care for the remixed versions that made it adjustable.

The holder is intended to sit on a flat surface which extends to the ends of the gear arms. The weight of the spool is supported directly under the roller brackets -- not supported by the base.

The roller brackets each have two seats for the roller axles. Place the roller axles in the outer seats to get a wider support base for the spool. Use the inner seats to accommodate spools with a small diameter.

While uploading, I realized that I didn't design a filament guide that goes through the enclosure top. I like this one, https://www.thingiverse.com/thing:2114888, and this one, https://www.thingiverse.com/thing:2740467, so I'm not going to design a new one.

Edit 07/14/2018: A few people have reported that the rotating joint between the link arm and the base is too loose. I have uploaded two alternate STL files for the link arms that have tighter tolerances for the link/base joint and for the link/peg joint. The original link arm has 0.10mm modeled fit gap (radius) for the base joint and 0.18mm modeled fit gap (radius) for the peg joint. The first variant, alt_link_arm_07_10.stl, has a 0.07mm fit for the base joint and 0.10mm fit for the peg joint. The second variant, alt_link_arm_04_07.stl, has a 0.04mm fit for the base joint and 0.07mm fit for the peg joint. I can easily post other variants if required.

Don't forget to enable support material for the link arms. (I also recommend flipping these alternate link arms over from the position in the STL file. See the original link arm STL for the preferred orientation on the print bed.)

If you make this thing, I would appreciate feedback on how well the joints work and if one of the alternate link arms worked better for you.

Edit 10/15/2019: I deleted my STL file for a roller and axel around a 608 bearing. Please refer to this thing for a better bearing roller solution: https://www.thingiverse.com/thing:3791583 by https://www.thingiverse.com/munzli.