Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4888950.
Remixed side spool holder to include locking twist tabs and lip on mount for better retention to rail. More detail at: https://youtu.be/Jp7mRxM1Az8
M3x40 screw and M3 nut hold the base and arm together.
Printed at 0.28 layer height, 15% infill, in PLA.
6/21/2021 Added a short foot version to fit a stock Ender 3/Ender 3 Pro
Changed name of Long Foot version that fits Aquila, Ender 3 Max, Ender 3 V2 and printers with the rubber foot shown in the video.