My first really nice machine was a Nelco, purchased back in 1972, and I loved it. I don't remember why I got rid of it but I believe, because I was moving around so much, that it was just too heavy to continue moving around so I had to give it up. Be sure you check both the bobbin and upper tension. The bobbin tension is easy to fix, upper tension is trickier. Take it in and ask your service technician to give you an estimate and explanation of what's wrong. If it's an easy fix - go for it! The older machines have all metal parts, are heavier and more durable, which is a major plus when quilting. My Nelco did everything a Pfaff could do for about a fifth of the cost. I wish I still had it.