Summary

This model is designed to help you spool your filament automatically using a motor. Running the motor at the right speed is difficult as the spool effective diameter varies when the spool becomes full. This system included a printed break between the mains shaft and the spool to stop the rotation is the tension is too high on the filament. Most types of spool are compatible.
To build this you need on M8 threaded shaft, 2608 bearings and 4M8 nuts. Print one “Spool roller main body”, one “Spool roller cover” and one ” Spool roller spring”. The number associated with the spring file is the number of spring arm, and so the tension applied on the spool. I have satisfying results with 5 arms.

I applied just a few drops of oil in the friction part and did not observe any damage on the parts after about 2h of continuous use.

You can see the system at work in video here: https://youtu.be/6uQI6wHndj0

Compared to my previous model (https://www.thingiverse.com/thing:4981507), in this design the tension is easier to adjust, the tension is more continuous, and more parts are printed.