Following is the handout I worked up for tomorrow's class and I thought it would be a good idea to post it here. Sorry there are no pretty pictures to include, but I will have lots of pretty pictures down the road. Promise!
Basically, the same rules apply for both sewing machines and sergers. The majority of sergers use the same needles, but always double check the user manual provided with your machine. If you do not have a user manual, most can be found on-line by using your favorite search engine.
Universal sewing machine needles are used for most woven fabrics, light to medium heavy in weight, and for stable knits. Use a ball point needle for jersey knits. “Stretch” ball point needles may be needed when sewing with spandex. When working with these types of knits, always run some test seams!
One important rule to remember: NEVER use a needle larger than a 90/14 in your serger. The larger needles may interfere with the loopers in forming the overlock. If you will be doing a lot of serging on heavyweight fabrics requiring a larger needle, invest in a good industrial serger.
Change your needles after 5 to 6 sewing hours. If you notice your serger “skipping” stitches, most likely one or both of your needles are either worn out or damaged. One super nice thing about sergers is that needle damage is less likely to occur since pins are never run under the needle.
For most garment applications, serger threads are the best thread choice. No matter what fiber they are made from, threads spun for sergers are lighter than standard sewing thread, and are typically found on large cones which last a good long time. The loopers take up a LOT of thread!
You can use regular sewing thread in the left and/or right needle if you cannot find in a cone with that “perfect” color to match your fabric. Avoid using regular sewing thread in the loopers for garment seams as the thicker thread will cause unwanted bulkiness in the finished seam.
There will be times, however, that you will use a wide variety of threads in the loopers for decorative seaming. “Rolled hems” and “flatlock” are two serger applications that can use all sorts of threads in the loopers. The loopers can handle much thicker threads than the needles.
Most current sergers will have a couple of knobs on the side. One usual knob is the stitch length and the concept is identical to a sewing machine.
The other knob you will usually find on your serger is the “differential” feed knob. That is the one that will have an “N” along with some numbers on either side of the “N.” This is because most sergers have TWO sets of feed dogs, one in front, one behind. When the differential knob is set to “N” (meaning “neutral”) both dogs work at the same speed. When changing the differential, one dog begins to work at a different speed relative to the other. This speed differential is why sergers are great to use!
As a general rule of thumb, when sewing with knits, you will turn the knob “up” and when working with really lightweight fabric you will turn your knob “down.” Always, always, always sew a test seam before starting your project to see if any adjustments need to be made. If your seam is “waving” play with the differential knob until the seam lays flat.
Of course, there may be times you will want the “wave” to happen, for decorative purposes.
All sergers have tension settings for each thread pathway and the trick is to get all four threads balanced. Different threads AND different applications will require different tension settings. Get into the habit of making notes of which tension settings gave you the perfectly balanced stitch formation for each application.
Keep a notebook of fabric samples complete with notes on thread used and tension settings.
Many sergers give you the options to adjust the cutting width. This determines the amount of fabric that will be caught up in the overlock. When seaming thick, plush fabric, you may need to decrease the cutting width so that the seam is not overly bulky. When seaming superfine woven fabric, you may need to increase the cutting width to provide a stronger seam. Quilters who enjoy piecing with their sergers will use a cutting width that gives them their required scant ¼ inch seam.
Rolled hem lever
Most sergers have a lever that lies parallel to the feed dogs right to the right of the needle area. When the standard overlock stitch is desired, the lever is pushed (away from you) so that it lies at the needle area. When a rolled hem is desired, the lever is pulled (towards you) back so that there is very little width in the stitch formation.
ALWAYS thread your machine in the order specified by the manufacturer
(usually upper looper before lower)!
ALWAYS sew a test swatch!!
ALWAYS have fun!!!