on my plastic grind machine one of the side hubstacks wont spin that well so i can only hold it in my hand for like 5 seconds at most and i cant do the trick where you hold the hubstacks and start the yoyo like that. so is there a way i can fix this? ive tried breaking it in for a while but it doesnt seem to be getting better.
If it’s new contact the store you bought it from and tell them your problem. If it’s not new then sounds like you may need to clean your bearing. There are many tutorials on how to do that.
try cleaning the bearing on the hubstack that doesn’t work.