You need to adjust the tension when the stitches on the top and the bottom do not look the same. You almost never need to adjust the bobbin tension. Try sewing with a different color thread in the top and the bobbin. If neither color shows on the opposite side your tension is fine. To sew on heavier fabrics use a piece of scrap fabric to test it first. The thread tension is tighter at the higher numbers. I hope this helps some. You might want to look at this website. Colleen

Here is a link that might be useful: Tension

The only time I loosen my tension is when I'm doing satin stitch applique. The rest of the time it stays on 3 which is about the center of the dial.
Susan

Check your sewing machine manual. It should have pictures of the stitches as they should be and when the tension isn't right.

I have 2 machines - one has a drop in bobbin and the other has a vertical bobbin, and the thread comes off counter clockwise on both.

Donna

If I were able, I'd CHEERFULLY throttle every one of those idiots who instilled in their pupils a fear of the routine, NORMAL machine adjustment. I really mean that!

Look, I grew up in a home where machinery was a TOOL, nothing more. That meant that WE, as operators of it, needed to understand it and not fear it. Later, I worked in "the line" in garment factories. As a "stitcher" it was MY responsibility to know how to properly adjust the machine I was operating so it performed properly for its function.

Later, when I was in charge of teaching new stitchers their jobs, I was a total "hard ass" about understanding the machine and knowing how to adjust it. I regularly walked "the line" and screwed up the settings on machines. Skilled, qualified operators ALWAYS run a stitch test and make adjustments if they're able. If they're not, that's what the supervisor is for... and that's a teachable moment!

Start with your manual. Go back to it again and again. Imagine yourself on the prairie with your new Singer that cost your husband a month's pay... and TEACH YOURSELF! if you can read, you can do it... but you have to follow the directions and THAT'S the skill that seems to have fallen woefully by the wayside...

Yes, it's frustrating the first few times. But keep looking at the pictures! make small adjustments every time. Learning to adjust your machine is time consuming the first few times, but you develope a "feel" for it. REALLY. And the more you accept that proper performance of your machine rests on YOUR willingness to adjust settings, the more quickly your enjoyment of a variety of projects will follow.

I know I've given you nothing "concrete", but knowing how to adjust your machine is something you grow into... but NEVER be afraid to take the first step and go for it. If you screw it up to such an extent that you can't "get it"... insist that the mechanic allow you sit next to him as he brings it into proper adjustment. It's what you're paying him to do, after all.