What are the two adjustments of the sewing machine?
There are two types of tensions on a sewing machine – the upper or top tension and lower or bobbin case tension. The tension of the top thread is controlled by the tension dial. And that is usually the culprit for your sewing tension troubles.
Why is my thread bunching underneath?
A: Looping on the underside, or back of the fabric, means the top tension is too loose compared to the bobbin tension, so the bobbin thread is pulling too much top thread underneath. By tightening the top tension, the loops will stop, but the added tension may cause breakage, especially with sensitive threads.
How do you adjust bobbin tension?
To tighten your bobbin tension, turn the tiny screw on the bobbin case a smidgen clockwise. To loosen bobbin tension, turn the screw counterclockwise. A quarter turn or less is a good place to start.
What tension should I use for thin cotton?
Use size 70/10 for really thin cotton like voile, size 80/12 for light to medium weight cotton, and 90/14 for thick cotton like denim.
If your thread is pulled tight on the underside and not forming an even stitch then (counter-intuitively) it’s usually the top thread tension that’s wrong. Sometimes very lightweight fabrics such as sheers can get dragged down into the machine so it’s a good idea to use a straight stitch plate.