There are lots of variables that decide this. You can have two machines that are the same but if the tension is off a little the settings may need to be set differently to get the same results. I'm really lucky, I have the viking diamond deluxe emb, a brother emb, a babylock serger and on all of them the tension is self adjusting. I never have to change it. I've had my diamond for about 4 yrs so that's a lot less stress on me not having to worry about this one thing.