Overlockers (AKA "sergers") are wonderful machines... most of the time! Great for stitching knit fabrics or finishing the seams on woven garments, once you get the hang of them they're super speedy to use.
(And, if you do need a helping hand to get to grips with them, check out my bestselling online workshop,
Make Friends with an Overlocker or Serger.)
Overlockers do need adjusting so the settings match the fabric and seam that you're sewing. Whenever you start a new project, take some time to sew a test swatch and adjust the knobs if you need to.
This is what you're aiming for - perfectly balanced stitches. (This picture shows four threads - you may have three instead if you're sewing lightweight fabric or seams that aren't going to come under too much strain.) I've used different coloured thread for each looper and needles so you can easily see how the stitches link together.
If your seam doesn't look quite right, here's a quick reference guide for seven common issues and how to fix them...
The loops from the right side are peeping out on the wrong side!
If the upper looper thread loops are visible on the wrong side, they’re either too loose or the lower looper thread is pulling them too tight. So you can either turn the lower looper tension dial down or turn the upper looper tension dial up. Adjust them one at a time, a little at a time, sewing a test swatch each time until the loops are staying on their own side.
