"Chat Bubble": Minimalist Low-Profile Bearing Spool Holder for MK3S, MK3S+

thingiverse

This is a small profile, economical, strong, easy to print and assemble spool holder for the MK3S & MK3S+ with 608 bearings for smooth rolling. Each side has a retainer to prevent spools from jostling around, which also lends strength to the overall design. The retainers have a very slight raised edge to reduce surface contact and friction against the spool as it rolls. Because there are no other moving parts besides the bearings themselves, there's little to no vibration during use. The fillet curves and tuned tolerances allow easier removal and repositioning onto the frame between different spool sizes. The spool sits as far forward as possible without hitting the extruder at max height, which helps smooth out the filament path feeding into the extruder and further reduces tugging, particularly if the spool is near empty. There is also a channel in the back to allow wires from any LED lighting to pass through. V2 takes into consideration MichaelO's feedback from V1, lowering the bearings' position and reducing the profile even further. Assembly requires 4x 608 bearings, also known as skateboard bearings. Simply press the bearings onto the shafts, and secure the other half of the spool holder over top of them. Each half fits together neatly and can be glued or fastened. 3x M3x20 screws with matching M3 nuts are needed if fastened. The design is very forgiving with print settings, but I used .2mm layer height, 4 perimeters for clean prints and strength, and 15% rectilinear infill. I've also used default .2 settings with no problems. PLA was perfectly fine; PETG will undoubtedly work too. No supports needed. Gcode provided is for PLA and 4 perimeters. One printer will need a set of 4 pieces total, included in the STLs. Each part is small enough that all necessary pieces easily fit onto a MK3s bed for a single print. The overall fit of the holder onto the frame is precise, but still allows for repositioning while on the frame. However, there is still variance of the frame dimensions between printers, so tightness onto the frame may vary. One of my first Fusion 360 projects, so feedback is welcome for improvement. 3MF and full print bed STL sets are available at: https://www.prusaprinters.org/prints/55288-chat-bubble-minimalist-low-profile-bearing-spool-h