Filament Stand Side Frames, suitable for an extended bolt like "The One - Anet A8 - Universal Spool Holder".

see https://www.thingiverse.com/thing:4927408 for a suitable nut and bolt.

Additional hardware for assembly:

• 2 - 4 lengths of M10 threaded rod of suitable length (225mm lengths in my case).
• A slightly shorter M8 rod for the bolt (210mm in my case).
• 2 x 608ZZ 2mm bearings.
• For each M8 & M10 rod, 4 x hex nuts and washers.

I've made bosses for 4 rods, but two are probably sufficient. I used 3 because I'd already cut the third one.