Ender 3 Filament Roller Guide for R188 Fidget Spinner Bearing, No Additional Hardware Required

thingiverse

This is a revised version of the filament guide by Holspeed, adapted for use with a R188 fidget spinner bearing (12.7mm/0.5" outside diameter, 6.35/0.25" inside diameter). The modification utilizes a spare R188 bearing from a fidget spinner, readily available when 608 skateboard bearings were not in stock. To minimize hardware requirements, the design replaces the screw with a 3D printed pin and glue-on cap that fits directly onto the bearing without spacers. Additional tweaks include making the wheel slightly thicker to fit snugly into the fork without spacers. By positioning the spool holder at the leftmost point of the top crossbar (refer to photos), the filament path becomes direct to this wheel guide, eliminating the need for additional components and keeping the Ender 3 footprint minimized. The STL file is configured to print all four parts simultaneously. Printed in PLA with a layer precision of .16, it fits perfectly on my Ender 3 Pro and the bearing. The hole for the pin has been sized to fit tightly without support; if you can achieve perfectly round vertical holes, you may find the pin slightly loose. I have also uploaded my Sketchup file, which I was able to modify thanks to Holspeed's kind gesture of sharing his original design.