Spool Roller (up to 1kg rolls, with bearings)

thingiverse

The problem is that center axis spool rollers don't generate enough friction, and every imbalance in the filament spool becomes immediately apparent. I've experienced the issue of filament slipping from the spool myself, so I set out to design a tube spool roller where the spool rides between tubes, reducing the likelihood of filament jumping off. The available designs on Thingiverse often place the spool too high for my taste, which is why it's a balancing act. This spool roller is designed to accommodate 1kg spools up to 78mm in width. I included an optional sleeve roller for 608 bearings as an alternative, just in case the tube rollers turn out bumpy. See the warning below. Designing something and assuming it will work is one thing; actually seeing how the printed piece performs is another. The problem with these rollers is that every bump and imperfection becomes visible during rotation of the spool. Due to Simplify3D's retraction blobs, the rotation is very rough and bumpy, even after I sanded the roller extensively. That's why many people use 608 bearings directly instead of printing a sleeve tube. I know now why so many people are using 608 bearings directly. So try the rollers at your own risk because roundness quality depends on your slicer settings and printer performance. Even after rotary sanding, my roller tubes developed flat spots, causing the spool to roll like it's on wooden wheels. To ensure perfect roundness, you'd have to print with 100% infill. And even with a layer height of 0.1618mm, I encountered bumps from layer start/stop points. Not severe like retraction blobs but enough to stop the roller tube spinning. You'd also need to sand these spots down.