Lower Perpendicular Spool Rack for the Ender 3. Uses the stock screws that came with the printer. Use the two M5x8 screws that originally hold the spool into its top position and the two M4*14 and M4T nuts to attach it to the printer. Put in the screws in and out once so that it is easier to mount.
The difference between the two options is that one has threads for the M4*14 nuts and one does not. Not having the threads makes a little easier to install.
Got the idea from thing: 2964818 which used none stock screws. Remade from scratch to use stock screws.
Please let me know if your Ender 3 did not come with extra M4*14 screws and/or M4T nuts like mine. If this becomes the case I will remake the design to fit what comes with most Ender3 printers.
If you want your spool to face the other direction just go to my other version here: https://www.thingiverse.com/thing:3362344