The SERGER, also called an overlock machine, is a special sewing machine that can stitch, trim, and over cast a seam all at the same time. Moreover, it's twice as fast as a conventional machine. See Fgr. 1.
Because a serger can handle thicker threads than a conventional machine, it can create special effects on seams and edges. It also does a special edge finish, called a narrow rolled hem.
The serger can't replace a conventional machine. It can't make buttonholes, insert a zip per, or do embroidery. Using both machines, however, allows you to make clothes with the same sewing techniques used for ready-to-wear.
Sergers are described by the number of threads they use. Machines may be three-, four-, five-, and eight-thread machines. Each thread sits on a separate spool pin on the serger. Although an eight-thread serger doesn't use all threads at the same time, it can create all the versions of a serger stitch. A serger may have one or two needles.
Only the needle thread penetrates the fabric when serging.
SAFETY TIP! Never sew over pins with a serger. The knives will cut through a pin, which dulls the blades. The pin fragments can cut your face, hurt your eyes, or damage the inner workings of the machine. If pins are needed to hold the fabric pieces together, place them 1 inch (2.5 cm) away from the edge. A glue stick or basting stitches can also be used.
Fgr. 1 A serger can trim, stitch, and overcast in just one step.
Fgr. 2 Parts of a Serger: How does a serger differ from a conventional machine? Spool pin; Pressure control regulator; Tension controls; Side cover; Front cover; Thread guide pole; Thread cone; Spool base; Hand wheel; Power switch
Fgr. 3 Serger stitches are formed over the edge of the fabric. Edge or fold; Heavier thread fits through looper eyes; Upper looper; Lower looper
Fgr. 4 What purpose do the knives serve on a serger? Rear feed; Front feed
Fgr. 5 What is the purpose of the differential feed on a serger? Movable knife; Presser foot; Stationary knife; Right looper; Left looper
Fgr. 6 Three-Thread Serger Stitch: Needle thread; Upper looper thread; Lower looper thread; Needle thread
Fgr. 7 Four-Thread Stitches Four-thread overlock stitch; Four-thread safety stitch; Four-thread mock safety stitch
Fgr. 8 Two-Thread Serger Stitch
Fgr. 9 Two-Thread Chain Stitch: Needle thread; Looper thread
Underhanded Uniquizing Effort Sub-Series:
Sewing Machine Feet
Sewing machines have a basic presser foot that's adaptable to many sewing tasks. Newer sewing machines have snap-on feet, which are easily interchangeable. Specialty feet can expand the capabilities of your sewing machine and ease the completion of various tasks. Sewing machine dealers are the best resource for purchasing them.
Walking feet are special feet that feed the top layer of fabric the exact same way the feed dog feeds the lower layer of fabric.
Cording feet hold cording in place while sewing cording or corded pin tucks. The foot holds the cording and prevents it from wandering.
Darning feet allow you to do free-motion sewing. Free-motion sewing and quilting are techniques used for decorative quilting and artistic thread work.
A quarter-inch foot is designed so that the edge of the foot is used as a guide to sew a perfect quarter-inch seam. This foot is especially helpful for piecing quilting.
A ruffler is a bulky foot that will automatically gather and sew fabric in one step. Adjustments to various parts of the foot control the amount of gathering that's achieved.
A rolled-hem foot feeds the fabric, keeping it perfectly folded for a rolled or baby hem.
PARTS OF A SERGER
Fgr. 2 shows the parts of a serger. Instead of a bobbin, the serger has two loopers, called the upper looper and the lower looper. See Fgr. 3. The two looper threads come up from underneath the needle plate. The upper looper thread appears on the top of the fabric, the lower looper thread on the underside. The two looper threads interlock at the fabric edge.
Fgr. 10 Rolled Hemstitch: This stitch is often used on placemats and napkins. Upper looper thread; Lower looper thread
Fgr. 11 Three-Thread Flatlock Stitch: Lower looper thread (straight line); Needle thread
Fgr. 12 Creating a Flatlock Seam: 1. Guide fabric under serger so stitches overhang edge of fabric. 2. Gently pull seam flat. 3. Finished flatlock seam has loops on one side, ladders on the other side.
Fgr. 13 Cover Stitch
Fgr. 14 Sergers sew seams as well as hems. They can also be used for decorative seams that show on garments, as on a vest or jacket. Another use is creating stretchable seams, such as those needed for a pullover top with ribbing at the wrists. Overlock seam; Conventional seam with overlock finish; Blindstitch hem; Narrow rolled hem
Fgr. 15 Balanced Serger Stitch: Upper looper thread; Lower looper thread; Needle thread
Tension control. To identify the tension dial that controls each thread, make some practice seams using different thread colors for each needle and looper.
Change the dials to see what happens to the stitch.
Tension settings. Start a notebook where you record the tension settings for different fabrics and threads. Include a sample of the stitch on a fabric swatch.
You can refer to this notebook the next time you use a similar thread and fabric.
On the right side of the needle plate are move able and stationary knives. These trim off the excess fabric before the stitch is formed. Most machines have knives that are retractable so you can serge without cutting the fabric.
Some sergers have a differential feed, which is two sets of feed dogs that move the fabric through the machine at different speeds. This can be used to gather one layer of fabric to a straight piece of fabric. It can also prevent puckered seams on lightweight, silky fabrics and prevent wavy seams on stretchy knits.
Some sergers create only one or two stitch variations; others perform several. An eight thread machine can create all of the stitches. Here are different types of serger stitches:
• Three-thread serger stitch. This basic stitch is formed with one needle and two looper threads. All three threads inter lock at the fabric edge. With this stitch, you can stitch and overcast a seam, finish the fabric edges of a conventional seam, and hem.
• Four-thread serger stitch. By adding an extra row of stitches, this stitch is more durable than the three-thread. It uses two needles and two loopers. One variation is the four-thread safety stitch, which consists of a two-thread serger stitch and a two-thread chain stitch. It is recommended for woven fabrics, because the chain stitch may break if the fabric is stretched. The four-thread mock safety stitch, another variation, can be used for both knits and wovens. These stitches are shown in Fgr. 7.
• Two-thread serger stitch. This stitch is created by one needle and one looper thread. See Fgr. 8. The two threads interlock at the fabric edge. The needle thread forms a V on the underside of the fabric. The stitch is used mainly as a seam finish on a conventional seam or as an edge finish.
• Two-thread chain stitch. This stitch is formed by one needle and one looper. Since it doesn't overcast the edge, it can't make a conventional seam. If the cutter can be disengaged, the chain stitch can be used for decorative topstitching. Only a few sergers offer this stitch.
• Five-thread serger stitch. This stitch combines a two-thread chain stitch with a three-thread serger stitch. The more threads involved, the more durable the seam.
• Rolled hemstitch. As a variation of the three-thread serger stitch, this stitch creates a narrow row of short, dense stitches. With a bulk-free hem, this edge finish is often used on placemats, napkins, ruffles, scarves, and garment hems. On some sergers, you can switch to the rolled hemstitch by changing the dials. On others, the needle plate and /or presser foot must be changed.
• Flatlock stitch. Use this stitch to create a decorative outside seam with two or three threads, depending on the machine. See Fig. 5 11. The stitch forms loops on the fabric top; a ladder stitch forms on the underside after the fabric is pulled flat.
Fgr. 12. The stitch is reversible because you can plan to have either the loops or the ladder stitches show on the outside of the fabric.
• Cover stitch. This stitch uses one looper and two or three needles for decorative hemming or topstitching.
Fgr. 13. Two or three parallel rows of stitching form on one side of the fabric. On the other side, one set of loops intersects with the needle threads. The stitch is reversible. Because it has some stretch, this stitch is often used for knits.
As you can see, the serger is capable of several versatile stitches. Some uses for these stitches are shown in Fgr. 14.
Each thread that forms a serger stitch has a tension control. Thus, you can adjust the tension separately for each looper and each needle. In general, the heavier the thread, the looser the tension should be.
To create a balanced stitch, adjust the tension whenever you change fabric, thread, stitch width, or stitch length. The upper and lower looper threads should hug the top and bottom of the seam and meet exactly at the edge. See Fgr. 15.
If one thread is pulled to the other side of the fabric or overhangs the fabric edge, the tension needs adjustment.
The needle thread should look like a line of straight stitching on the top of the fabric, with only tiny loops on the underside. If the tension is too tight, the seam will pucker. If too loose, the seam will spread apart when gently pulled.
Always check the tension by serging on a fabric swatch before starting a project.
If problems occur while sewing, incorrect tension or another condition could be the source.
This chart shows some possible problems and solutions:
Correcting Serging Problems
• Replace dull or bent needle.
• Check size and type of needle.
• Loosen upper looper tension.
• Rethread machine.
LOOPS FORM AT EDGE OF FABRIC
• Check threading at tension disks, take-up lever, thread guides.
• Increase looper tension.
• Check knife alignment.
• Serge a thread chain at end of seam so thread will not get caught under presser foot.
• Insert fabric in front of needle and knife.
• Check threading sequence.
• Check thread spool or cone.
• Loosen tension of thread.
• Replace dull or bent needle.
• Try a different thread.
STITCHES PULL THROUGH TO RIGHT SIDE OF FABRIC
• Increase needle thread tension.
• Check threading at tension disks and thread guides.
• Replace dull or bent needle.
• Use wider stitch width.
• Check knife alignment.
Fgr. 17 Serger Thread: Cone King tube Compact tube
SERGER THREADS AND ACCESSORIES
Conventional polyester or polyester/cotton thread can be used for general sewing. Because the serger sews faster and uses more threads in each seam, however, some special threads are helpful.
• Polyester or polyester/cotton serger thread. Similar to conventional all-purpose thread; slightly finer and comes on large cones or tubes. See Fgr. 17.
• Woolly nylon thread. Soft, fuzzy thread that stretches when sewn; good for serging swimwear and lingerie and giving a narrow rolled hem an attractive, "filled in" appearance.
Woolly nylon thread is used in loopers; all purpose serger thread is used in needles.
• Decorative threads. Various threads that include metallic, pearl cotton, silk or rayon ribbon that's 1/16” wide (1 to 2 mm), and crochet cotton; used in loopers to create special effects. Because loopers have large eyes, a wider range of decorative threads can be used on a serger than on a conventional sewing machine. Regular serger thread is used in the needles.
The following special notions help ensure smooth stitching with a serger:
• Adapter cones. Fit over spool pins to hold the large thread cones and prevent them from vibrating while the machine is on.
• Spool caps. Fit over the top of standard thread spools to hold them in place on the spool pins. See Fgr. 18. Always place the spool with the notch down to prevent the thread from catching in the notch and breaking.
• Thread nets. Fit over thread spools to keep thread from unwinding too quickly.
• Tweezers and a loop threader. Helpful for threading the machine.
Fgr. 18 Spool Cap; Notch
As the knife trims the fabric, it creates a great deal of lint. For good performance, keep the serger lint-free. Use the small brush that comes with the machine to remove lint from the area around the knife and loopers. Canned, compressed air is also good for cleaning and can be purchased at fabric, sewing machine, and camera stores.
Follow what the instruction manual says about oiling the serger.
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Wednesday, 2013-06-05 14:35