Fabric puckering in serger

We don't know what machine you have.

ALWAYS RAISE the presser foot throughout the threading process.
Try threading with the 4 colors of thread that match the machine diagram--makes it easier to see which thread is misbehaving.
ALWAYS thread each in the Correct Order...usually the top looper (#3) first, then the lower looper (#4), then the needles(#1 & 2). (Threading out of order will most often cause stitching problems.)
When threading each thread, grasp the thread below the thread tree and also below the tension disk and give a little tug to make sure the thread is completely seated (sometimes it will pop when it seats).
To start out, set the tension at the midway point (it's usually marked on the dial).
Test the stitch. Then tweak the tension disk of any threads that may be showing more on one side of the fabric than the other. The threads should meet in the middle of the fabric.

....

I don't know your model in particular but generally this is how you set up a serger/overlocker to create a rolled hem. Remove the left hand needle and thread if 4 threads are threaded). Now there is usually a lever around the stitching area that you slide back towards you to remove the stitching finger back (disengaged). Then you adjust the top looper tension looser (about 2-3) and lower looper tension tighter (7 or 8). Leave needle tension at normal tension (5). You may need to move the cutting blade to the right too. The technique is to cut the fabric wider but with a narrow stitch so the cut edge rolls under within the stitching. You want the top looper thread really loose so it rolls right around underneath up against the needle thread, the lower looper thread needs to be tight and almost invisible, pulling the upper looper thread down. I usually do a few test runs and check the stitching. Once happy, I turn the stitch length right down to 1 so it is very dense. This uses a lot of thread up.

Ideally use a wooly overlock thread on the upper looper as this "fluffs" out once stitched and "fills" in covering the fabric edge completely.
some good images here
Sewing Basics Narrow Rolled Hems with Serger Sew Mama Sew Outstanding...

here is a video

First of all ensure that the serger is threaded correctly.

The two setting which you mention are really a 'range' for an 'average' setting.

Using 'average' fabric such as a medium weight cotton, flannel, etc.; set each of the tensions in the middle of the range and test the stitch. There may be minor adjustment required to get a perfect stitch.

Once you have stitched that first sample, here are some possible minor adjustments required:
1. Tear-drop shaped loops on the underside: Check that the thread is firmly set in the tension dial by giving the needle threads a good snug pull above the tension dials while the presser foot is down.

2. The zig-zag like thread on top should meet the ziz-zag like thread on the underside right on the fabric cut edge. If the meeting happens on top: reduce the upper looper tension slightly and increase the lower looper tension slightly ... test sew and recheck. If the meeting is on the underside: increase the upper looper tension slightly and decrease the lower looper tension slightly ... test sew and recheck.

3. If the meeting does happen along the fabric cut edge but the meeting is hanging beyond the fabric cut edge: increase the blade position (that is, move the blade to the right). If the fabric is creating a ridge or tunnel; move the blade to the left slightly.

Please let me know if this has solved your problem. Otherwise let me know what is happening with the stitch quality.

Here are a few things to try.
1. Make sure that correct type of needles are being used, both are the same size, and that the needle size matches the fabric weight. This is the first serger to use 15X1 needles.
2. Make sure that the needles are installed correctly and are pushed all the way up. Have you replaced the old needles with new ones, not other used ones?
3. Thread has a shelf life, it can expire over-night. Just to eliminate this possibility, replace all threads with fresh good quality serging thread (and not just another spool which was purchased some time ago).
4 It sounds like you have re-threaded the serger correctly according to manual instructions. Here is a sure fire method:
- thread the upper looper and place the thread behind the needles under the presser foot. Make sure that the thread is lying firmly between the tension discs.
- thread the lower looper (the tricky one). Check that the thread is between the tension discs as before and place the thread over the upper looper and then behind the needles, and under the presser foot.
- thread the needles, checking that the thread is between the corresponding tension discs. Place the thread under the presser foot.
5. Check stitch length.
6. Check if the problem persists with other fabric types, use two layers. If the problem occurs with only a particular fabric, then the cause is incorrect needles.
7. Check tips on both upper and lower loopers. They should be free of burs, smooth, and have a semi-sharp point.
Hopefully this will solve your problem, if not it may be time to have it inspected by a qualified technician.
Please rate how effective were these suggestion in solving your problem, it is important to me.

Which stitch are you using?

To check thread tension for straight stitches, use different colors of thread in your top thread and bobbin. If the top thread shows on the bottom of the fabric, turn the dial counter-clockwise (towards a lower number). If the bottom thread shows on the top, turn the dial clockwise. Do not adjust the tension too much (for example, go from 2 to 2.5 if increasing the tension) at a time; test another set of stitches. Alternatively, you can adjust the bobbin tension in the reverse directions. However, it's very easy to damage the set screw in the bobbin case so do this as a last resort. Since this is a vertical bobbin case, put the bobbin in and hold onto the thread. If the thread moves when you dangle the bobbin case, tighten the screw. Loosen the screw if the thread doesn't pull out of the bobbin when you hold the unit.

For zig-zag decorative stitches lower the tension until the puckering stops. Usually the top thread will show on the bottom of the fabric.

If the tension is not changing when you turn the dial, make sure that the presser foot is down. The sewing machine may need repair. The tension mechanism depends on a spring and that can break. See the Singer site for a parts breakdown and contact your Singer dealer for the parts.

If the top and bottom fabric are not moving at the same rate, you can get a different type of puckering. You may want to get an even feed foot if there are several layers of fabric.

The manual for the 3116 is available from Singer: http://www.singerco.com/uploads/download/438_3116.pdf .

I hope this helps.

Cindy Wells

Are you wanting to use the serger to sew a hand knitted sweater together? or do you mean a sweat shirt knit or other knit fabric. If it is the first option, I'd say don't bother, as you can't do it with the blades working because it will cut your knitting and the wool will unravel in the seams.

If it is the second option then I would start with the following settings.

Four thread stitch, so both needles and the upper and lower loopers threaded. Set tension on all four dials to 5, stitch length to between 2 and 3, and differential on zero. Move the cutting blade over to the right for a wider seam. Now test stitch on some fabric scraps double layer and see what the seam is looking like.

Now you want to adjust a couple of things: firstly width of the seam. Is it the size you want? If you'd like it a little narrower, then adjust the cutting blade back a little to the left to narrow the seam slightly - just depends on the fabric weight. For example if it is a loose open weave like boucle you would want a wide seam to make sure it holds the fibres fully.

Now you can adjust the upper and lower loopers to get the thread wrapping around the edge looking nice. Look at the seam and the fabric inside it. Is it tunnelling and pulling up the fabric? if so, release tension on both loopers a half number to put more thread into the seam. Test stitch again and see if the loopers are meeting nicely on the cut edge of the fabric. Upper and lower looper threads should be meeting right on the cut edge so if this isn't happening and one showing on the other side, then tighten the looser one by half a number and test again.

If the threads are hanging off the edge then you have the choice of moving the blade to the right to cut less fabric off, or tightening up the looper tensions to pull in the thread.

That's it, hope this helps you to master your serger.

If you'd like some images and further explanations of other stitching you can do with your overlocker, then Debbie Coswell has some great information on line at www.sewing.about.com, just search "overlocker" to find the specific pages.


Good luck

I don't know your babylock well, some of these have automatic tensions and electronic stitch selection. But a rolled hem is achieved on any overlocker in the following way; the actual dials and knobs might vary a bit.

Firstly there is a stitch finger that you need to change or retract so that the thread can roll the fabric rather than staying flat. For a normal seam this finger sticks out in the area where the loopers and needle form the stitch holding the cut edge flat until the seam is made over it. But for rolled hems you want to retract this finger so it does roll.

On the Bernettes this is a little lever in front of the stitching area that you pull back to retract the finger. Have a look around where the stitch forms and you should see the finger. Some machines, its a part you change on the needle plate with a screw driver, or just move a switch or lever.

You want the right hand needle in place, remove the left hand needle.

Thread upper looper with wooly overlock thread, this is a fluffy nylon that pulls flat under tension but relaxes and "fills" out once its stitched into place. Gives that lovely covered look you see on shop bought tablecloth edges. Your regular thread in needle and lower looper. Usually cutting blade to the right side as you want it to cut more fabric than in the seam so it rolls under. Now loosen off the tension on the top looper, (I use 2 on mine but this is something you need to finesse with each machine), and tighten up the tension on lower looper, (about 7). Leave needle tension alone.

Now test stitch on your fabric, and finess the upper and lower looper tensions until you get the lower looper thread almost not showing, it should be right up against the needle on the underside with the upper looper thread completely wrapping around top and bottom, pulling the fabric under.a seam like this.


Test stitch and adjust upper and lower looper until this is happening.

Now, turn stitch length down to close up the stitching, probably 1 or 0.8 if you want a real satin stitch look to the hem.

Because of the stitch density this uses thread so do the finessing first, then turn the length down.

That's it! Now right down the tension settings you used and keep handy for next time.

a wide zig-zag on a light weight fabric single layer is almost guaranteed to pucker up, just because the thread is under tension and this is often stronger than the fabric being pulled together by the stitches.

However, if a straight seam is puckering, this could be caused by a blunt needle, too big needle, or too tight tension or too long stitch length. You should be able to vary some of these variables to reduce the puckering and improve the stitch appearance. Other things to check might be the top thread being caught up somewhere in the thread path and pulling on the stitching.

If I am finishing the cut edge of aa single layer of light weight fabric I would use a three step zigzag to hold the fabric firmly and neatly.

Hope this helps a little?

you might want to get a new thread or a needle
or try checking the functioning places by checking under