Why does my thread keep bunching up underneath?
Your Thread Tension Is Too Tight
Sewing machine manufacturers suggest that you don’t mess with your bobbin thread tension too much, but you should adjust your upper thread tension if you keep getting bunched up thread underneath your fabric. If your tension is too tight, it can pull your thread and break it.
What width should my sewing machine be on?
A straight stitch has no width so it makes sense to set the dial at “0”. However, each machine varies so you will want to set the Stitch Width dial at the position where the needle is centered over the stitch plate. This will give you the most accurate seam allowance.
How do you tighten thread tension?
Changing Bobbin Tension
You should see a small screw on the flat/closed side of the bobbin case. Turning the screw a tiny bit counterclockwise will loosen the bobbin tension; turning it clockwise will tighten the tension.