This is my first design, I cant seem to find any decent spool holders for my Two Trees Bluer printer that I am happy with. I basically started from the ground up with a design based on the Anet A8 spool holder which is one side as opposed to on top of the printer, a piece of 8mm Threadbar with M8 nuts will act as the Axle, you will have to also download and print the "Ultimate Spool Adapter" set. https://www.thingiverse.com/thing:1874612 This will centralize the spool on the threadbar which will then turn much easier on the holder.

Its designed to fit over the Ender 3 "V5 More Rigid Mount 2020 Ender 3 Filament Guide" https://www.thingiverse.com/thing:3712330 that I am using for my printer.

The bolts designed to be used are m4 x 12mm into the original locking nuts that the printers spool holder comes with.

I also added external supports for the holder which I am hoping will support the spool's weight, but again it is a work in progress so I will have to see how it goes. Pictures coming soon.

EDIT: I have now remixed and added the filament guide by "FurioPrints" as an option so you can print the complete spool holder with the filament guide, it will simply slide onto the top frame of the Two Trees Bluer Frame, It will also work just as well for the Ender 3 frame. Both files are included for your choice. I have also fixed the original file as the bottom gap that was supposed to fit over the filament guide was too wide. I have also added the spool adapters by "vidschofelix" so all you would need is a piece of M8 threadbar, an m8 nut, 2x m8 Nylock nuts, and 2x m4x12 bolts. I will add a wider version for bigger filament spools shortly