I really like the spool holder design by Webberen (referenced). I decided to use his design for my Airtight Filament Canister thing. I needed to add non skid pads to the cradle so it doesn't move inside the canister so I remixed the original design. While I was remixing it, I added a different bearing mount post with a spring split post which allows the bearing to pop on and is also a bit tolerant of an under size or over size post. I added some retro holes on the sides for fun and the pads for optional rubber feet. I also added some faint reference lines to the crossbar to help with spacing the two sides.
This cradle design requires only four 608 bearings, it prints quickly, is stable, and adjustable. This cradle can handle spools from 20 mm wide up to 120 mm wide.
If you would like an Airtight Filament Canister to keep your filament dry, check out my thing. This spool cradle works with the air tight canister.
PLA is fine
The cross members should fit the matching holes fine.