The author remixed this model.
Enlarged the spool holder for 2kg to 6kg spools. Lengthened the Axle for larger width spools.
Update1: Reinforced the longer axle with a 4mm hole to increase walls or glue in a 4mm carbon fiber rod. See photo. The self tightening action of the nut along with the heavier loaded donor spools puts lots of tension force on the axle when respooling very fast (i.e. power drill or motor) this can lead to a sudden failure of the axle resulting in unwanted consequences. Reprint this piece and glue in a 4mm carbon fiber rod with super glue and the part is practically undestructible.