A simple filament roller for AnkerMake M5 (probably works for the M5C as well and likely other printers). I looked around and everything just seemed way too over designed and engineered in my opinion. My printer is from 2023, so if AnkerMake changed the size of the filament holder bolt (axle) since then...
You'll need to print two and assemble them as seen in the photo.
Axle hole diameter is 8.75 mm
Roller diameter is 29 mm
Outside roller rim/lip diameter is 39 mm, which should be small enough for most, if not all spools to slip over.
Length is 42.5 mm each for overall length of 85 mm