If you have ever owned a Neptune 3 Pro, you understand how annoying the spool arm is. As great of a little machine it is, the spool arm was a huge design flaw. It holds your filament at an angle backwards from the center of mass on the printer, causing printing vibrations and flexing issues on the whole upper frame rail which can lead to poor 3D prints. This is my own take on a kind-of double remix with both @ladlaser58 (https://www.printables.com/model/865421-vertical-spool-holder-for-the-neptune-3-pro-with-u) ...and... @djpeaty (https://www.thingiverse.com/thing:6565710).
Okay so there are 4 files, the 1st is the main spool arm and the others are decorational trim that you may print in whatever color combo you desire.
For the main spool arm (in Cura) the resolution should be 0.2mm, the infill should be a minimum of 25% Gyroid, no rafts or supports, build adhesion type should be set to Brim at 5mm width, and lastly the wall line count should be set to 3.
For the three short, middle, and long trim pieces, resolution should be set to 0.1-0.2mm depending on your preferred aesthetics, the infill should be set to 100% Zigzag, wall count should be set to 2 (or default), brim set to 5mm width, and lastly no supports or rafts.
All files except the "Fill-In Long_V1" should be printed vertically. The long tends to fail when printed vertical. Total print time was around 6.5hrs. This print uses all of the original hardware and the 3rd hole at the front is meant for the runout sensor (side note, I had to modify the runout sensor to fit). PLEASE remix, make, and share all of your builds with me. Share any advice or concerns. I will try to address them all. Also the pictures listed show the prototype and the updated version.