Wanted something to keep my filament spool centered so it rotates easier. PETG seemed to have issues gripping in the extruder when the tension got too much. These solve the problem without spending 10hrs+ printing.

I would advise against making these solid, they need to be flexible so you can twist / bend them around the existing hub on the ender 3 pro. (I tried one and snapped it) hollow works well.

Takes about 30 - 40 minutes to print each one, two required as one isn't strong enough on its own to hold the weight. I put one on each side of the spool. (See photos) and it works well, not so loose that the filament just unrolls, but loose enough to allow rotation when tension builds.

Creality

Ender 3

No

No

.2

.2 layer
.4 nozzle
.8 wall thickness
.8 bottom layer thickness.
240 degree nozzle, 70 degree bed.

Nozzle about .4mm off the bed. Sliced with Ultimaker Cura, drawn in Solidworks.