I hear this frequently at my store, "my sewing machine just needs a tension
adjustment as it is making loops on the back of my fabric."
Many times it is not a tension problem. Here is a link to a you tube slide show
I created I hope it will help someone that is having tension problems that do
not go away with tension adjustments. This was done on a long arm quilting machine the Tin Lizzie 18 LS but the theory is the same for other machines.
Sewing machine basic adjustments.