The threads are not tight on my serger

try adjusting the top thread tension one number or letter higher
and sew on a scrap piece of fabric till the stitches look normal.

sergers the most frustrating machines. Every time you change fabrics you go through a tension adjusting phase.

First make sure you have threaded the machine in the proper order. upper looper, lower looper, then needles from right to left. Always thread any machine while the presser foot lever is in the UP position.

If you ever break a thread... you MUST pull all threads and rethread using the proper order.

Ok that's out of the way. Pull all your threads and get out several pieces of the same fabric scrap. Thread each pathway with a different color. This will help you determine which thread is giving you fits. Sew a test strip. Which thread is loose? tighten/loosen that tension. Keep doing this until you have a well balance seam. Then clip the colored threads starting with the upper looper thread, tie off to your proper color for your seam pull the thread through and up through the throat plate. proceed in this manner with lower looper, right needle, left needle. Sew a test seam.

Good luck.

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

Have you used an overlocker before? If not, I'd suggest that you obtain a user manual for it as they are completely different to a sewing machine and at some point you will need to rethread it. You can purchase one from here
http://pages.sewing-machine-manuals.com/173/PictPage/3923709707.html

This machine makes three and four thread seams, which is a combination of two needles and two loopers. For the three thread seam you can use either the left or right needle which gives you different sized seams. For the four thread you use both needles, one goes through the middle of the seam and the other is on the left side securing the seam. On most overlockers you are able to move the cutting blade too and this will reduce or increase the amount of fabric being trimmed from the right side.

This page http://sewing.about.com/od/sergersoverlock/ss/serger.htm will give you some general information on sergers/overlockers too.

So adjusting tension is a matter of changing the tension on the top and lower looper threads to close up against the cut edge, or moving the blade over to make the seam a little wider or narrower. You may also need to finess the left needle tension so that the seam doesn't pull apart, I always test serge two layers and then pull open from the right side and see if the needle thread is showing (it will show a little bit but you dont want it so loose that it pulls open. Only tighten the needles in very small increments though, as you'll break threads and needles if you turn them up too tight.

Hard to explain without seeing what your machine is seaming now. But as a rule of thumb, start with all four tension dials (or 3 if doing a three thread seam) on 5. If the tension dials are correctly calibrated then this should give you a pretty good seam. You may wish to lengthen the stitches, I usually work with stitch length of 2.5 (same as your sewing machine stitch length) Stitch length will be a dial on the right side beside the flywheel or in front of the blade area. The blade adjustment should be a little knob near the blade area too. There will be a lower fixed blade and a moving upper blade which sits against the lower one, they work like scissors to trim the fabric. So to adjust the blade, you will need to take the pressure off the upper blade, then wind the knob to move it left or right.

Different weights of fabric will behave differently on the overlocker so you do need to adjust tension for each new project. For example, if seaming a jersey knit you'd use a four thread seam, this gives elasticity and strength and you can join two garment pieces with this seam. You'd probably make a 6mm or 7mm wide seam, the left needle will secure the fabric and the loopers will encase the fabric smoothly while the right needle secures them and gives extra strenth to the seam.

But on organza for example, I would make a very narrow three thread seam using the right needle as the organza will roll inside the overlocking if you cut the fabric too wide.

And on something like curtains I would neaten the edge with a wide 3 thread seam using the left needle to get a very wide seam, the fabric wont roll so you'd need to loosen the two loopers a little to smoothly encase the cut edge.
For example, on this image above you can see that the looper threads are laying a little off the edge of the fabric in places, particularly the lower looper, (the side that looks like Y's where you can't really see the middle needle thread), so I would tighten the lower looper about .5 on its dial, then test again.

I hope that this makes sense to you, you will need to test serge, and adjust one dial at a time, test again and look at the result, then maybe adjust another thread until you are getting a smooth looking seam.

A rolled hem on any overlocker is formed by using the right hand needle only, and the two loopers to form a narrow three thread seam. You also need to retract the seam width finger as Trial2962 said. This is a little finger that sits on the stitching plate and the loopers form the stitching over it. By retracting it, the looper threads can form a narrow seam and in fact, roll the fabric inside the seam. You need to move the cutting blade as far right as it will go so you are trimming as wide as possible from the needle, turn the tension on the top looper rigth down to 2 so it is very loose and this thread wraps around to the underside. And tighten the lower looper tension to about 7 so it hardly shows and sits right up against the needle thread. Adjust and test until you get the seam looking like this, then turn the stitch length dial (on the right side by flywheel) down to 0.5 to close the seam right up tight. Lastly, if you can source it in the right colour, buy woolly overlock thread and run this through the upper looper only, this thread is fluffy and when not under tension, relaxes and "fills" out so the seam appears like a continuous coverage over the fabric.

You will need to practice a few runs and go slowly on corners, a curve is obviously much easier to serge than a right hand cover so if you can, cut the fabric with curved ends, much easier to get a great finish. When you chain off at the end, you need to unravel the tail threads and pull them inside the seam for a few mm with a needle to get a smooth finish, then trim the tail and seal with a drop of Fray Stop.

Hi. As a rule of thumb, once the tension is balanced on your machine, it shouldn't need adjusting. It's not something you adjust for each different type of seam or fabric (again, rule of thumb!). (Certain kinds of sewing, like free motion embroidery or when you use rayon thread, require particular tension adjustments, but for ordinary sewing, you shouldn't have to mess with the tension that often.
If the top tension is too tight, your top thread will be loose and basically just sitting on top of the fabric. You need to loosen it up so that the bobbin thread can pull the top thread down into the fabric.
Let me know if this helps, ok? I'm going to post a tip on adjusting tension so please check that out.
Happy Sewing!

Robbie

This is a tension adjustment problem. It's good to use two different colors of thread, like you did. From your description, the top thread (needle thread) tension needs to be tighter. As you tighten the tension of the top thread, you'll see that the top thread pulls the bobbin thread up into the fabric so it's no longer laying loose on the bottom of the fabric.

You'll need to have the pressure foot down when you tighten the tension. Tighten it a little, sew a practice seam, check to see what the stitch looks like. Tighten it a little more, sew, check, etc etc--until both top and bottom look the same--you shouldn't see much (if any) of the bobbin thread color on top of the fabric or the top thread color on the underside.

Let me know how this works for you, ok?


Robbie

the top seam is actually the bobbin thread. dots on the underside means that the top tension is too tight. you may have a piece of thread or something gummy caught between the upper tension disks.

Stretch fabric is made for using the differential feed on your machine, sergers love stretchy things. Try widening the stitch you are using and turn your differential feed down one notch to allow the machine to get a good grip on the fabric, you may need to bump the differential feed up more if it still doesn't stitch nice, keep trying on a piece of scrap fabric of the same as you are using until you are happy with the stitch.Another solution is to put some lightweight tissue paper under the seams and then tear it off after you have sewn the seams, this works but will dull your blades over time.

Sounds like your needle threads are not tight enough.

Do some samples using different colored threads, if necessary, to see which needle thread is not doing the job. Then tighten in increments till you get the right tension settings.

It helps if you make notes of the correct settings on that material for the next time. Start a sample notebook, for the different materials you might use with tension settings for each, and if you do any fancy stuff with your serger, like pintucking, puffing, elastic application, ruffling and such.