Excellent design! I printed deep groove ball bearings utilizing a bearing generator I found on makerworld and used 4.5mm BB’s. This thing is pretty darn quick at getting the job done. great work! If I had any constructive criticism, it would be maybe redesigning a way to apply better resistance on the spools. I used my hand to adjust the speed of the spool being transferred so that it wouldn’t uncoil if I stopped the winding. I read other comments about a gearing mechanism might be best. I think that could be easily achieved across the middle where the spring and other bearings are currently. If designed that way, the spools would spin at the same time and prevent any one spool from “free spooling”. thanks for the awesome print regardless.