Adjustable Spool Support

thingiverse

I started this project by modifying tdanro's "Adjustable spool holder for the Original Prusa i3 MK2" (https://www.thingiverse.com/thing:2122419) and transformed it into a shelf-mounted unit with increased capacity. This is admittedly an overkill, but I had some of the hardware already and just wanted to learn more about assembling a complex project in CAD. It's designed to print using default settings without supports (at least it prints fine on my Prusa MK3 without them, but YMMV). The printed parts include: (1) Center.stl (1) Center_top.stl (1) Pinion_bottom.stl (1) Pinion_top.stl (1) Knob.stl (2) Slide.stl (2) Rack.stl (4) Roller.stl (4) Standoff.stl Hardware: (2) 8mm x 200mm shafts (https://www.mcmaster.com/6112k44) (4) M8 x 1.25mm socket head bolts (https://www.mcmaster.com/90128a276) (4) M8 x 1.25mm nylock nuts (https://www.mcmaster.com/94205a260) (4) 8mm LM8UU linear bearings (https://www.mcmaster.com/61205k75) (4) 608/skateboard Bearings (https://www.mcmaster.com/5972k91) (4) 4-40 socket head screws* (https://www.mcmaster.com/91251a149) *The socket head screws I used were 1.5" long to mount on a half-inch thick shelf, but any similar-sized machine or wood screw would work, and you might want to change the mounting holes accordingly. Assembly: Pretty obvious, except for the pinion gear. I split it in two to make the print simpler. It aligns and joins with two pieces of scrap 1.75mm filament. (BTW - the best glue I've found so far for PLA is DAP Rapid Fuse). Once the glue is set, use an x-acto to clean up any excess glue and debur. The LM8UU bearings seem to vary in size somewhat. I've sized this for typical metal-cased bearings, but also had some drylin bearings that were fairly loose. Note that the standoffs go between the bearing and the slide so that the bolt can be tightened while still ensuring that the bearing turns freely.