Serger Series – Part 1: Anatomy

On November 4th 2013 I got my longed for overlocker. *Confession*. Up until a few weeks back I had only ever used the 4 thread overlock that it had come factory threaded with. I had literally been too scared to unthread the thing for fear of being unable to re thread it. Resolutely sticking to this method of changing the thread cones. Sound familiar? Well a few weeks ago, after my machine had a bit of a hissy fit at me; I decided enough was enough. I decided that, like in any successful relationship, if she and I were going to fulfil our relationship potential; then I had to invest some time in getting to know her better.

So over the past few weeks I’ve taken my overlocker to bits (yep, with a screwdriver and everything) cleaned it, reassembled it, and played with it. I’ve watched you tube videos, played with sample swatches  and **shock horror** read my manual!! (C’mon…I’m not the only one to never read a manual, right??) What I’ve discovered is that overlockers are nowhere near as scary as I thought. Yes, they still sound and run like sewing machines on steroids BUT threading one is now like “oh, was that it?!” and diagnosing (and correcting) the cause of loopy weird stitching is now a piece of cake.

So I  thought I’d share my discoveries in a new series aimed at beginner, scaredy cats like me. Cos I know you’re out there. Just wanting to get serging/buy a serger  and wondering if you’ll be able to get to grips with it. Well….you will!

The best place to start is a tour of a serger and it’s various components. What they are and what they do. First I better introduce you to my machine. A Singer 14SH754.  A 2, 3 and 4 thread overlock machine with differential feed. (We’ll get to what differential feed is in a bit!) Here’s how she looks from the front….

and from this angle you can see the key elements at the side and the back of the machine. Ready for the tour? Here goes….

Starting at the back you have the thread spools. No different to a sewing machine except there are 4. Those clear plastic things that sit at the bottom of the spools are removable and are there to accommodate the large thread cones that you typically use on a serger. Remove those and you can use a normal size thread spools. So if you have a more obscure colour and don’t want to buy 4 massive cones of it, you can use normal ones too! In the middle is a telescopic metal thread bar. The whole thing extends up and the threads slip inbetween the crossover part at the top of each loop and sit in the bottom of the loop. There to separate and guide the individual threads and keep them at tension.

Visible just behind the carry handle in the previous pic. More thread guides. This time they look like the hook part of a hook and eye fastening. There to help keep the the threads separated, at tension, and guide them through that channel there, that leads to the tension dials/discs around the front….

Lastly (at the back, for now) the presser foot lever. Just the same as on a standard machine. Raises and lowers the presser foot. Simple as. That white “bar” you can see to the left is part of the knife mechanism. We’ll get to that in a mo!

Moving around to the side. There’s your presser foot. Nothing strange there. Note the angle of the needles and the presser foot bar though. On a standard machine the presser foot bar and needles point straight down. Slightly angled on a serger. Also note the white bar that we saw in the previous pic has the blade attached to it….

Presser foot lifts up and down as on a standard machine. Underneath are the feed dogs and throat plate. As on a standard machine. Presser feet are changeable (for different actions/stitches) on overlockers just as they are on standard machines. So…just the blade that’s any different here really!

There are your needles from the front. Released and changed using those tiny screws. Left needle (B) sits higher than the right needle (A). The little “pig tail” curls keep the needle threads separate, at tension and guide them into the right place for threading. In the right foreground of the pic you can see that blade again…

The blade points downwards and snugs into the presser foot. You can disengage it by pushing it in towards the white cylinder and using the black knob on the right to rotate it out of the way…

Here is the blade from a different angle. In reality there are 2 blades. The one that is attached to the presser foot bar and moves up and down. And a fixed blade that sits just under the throat plate/feed dogs…as you sew, the fabric slides over the throat plate and between the upper and lower blades…

As the needles move down, so does the upper blade. Slicing the fabric between the upper and lower blades in the process. Ouch! (At the same time that this is happening, the needles behind it will be picking up the threads from the lower looper to help form the stitch on the underside of the fabric)

Just infront of the blade you can see a white switch with “R” stamped to the left of it and “S” stamped to the right; and below that a black dial. This relates to adjusting the stitch width. For normal overlocking that white button is pushed forward to the “S” position. We’ll revisit “non normal” stitching in a later post 😉

So we’re back round to the front….

Open the door at the front and this is what you see. The part that seems scary. The inner workings of the upper and lower loopers. But bear with. It’s honestly not that scary 🙂

Let’s start up top with the tension dials. Ignore the numbers here. I’ve been playing and we’ll get to those in another post. For now let’s talk function. Just the same as a standard machine except, again, there are 4 instead of 1. They set how “tight” your stitch sits in the fabric. Inside each tension dial are 2 metal discs that look a bit like finger cymbals. Same as a standard machine, the higher the number you set the dial, the closer the discs squeeze together and the tighter they hold the thread that runs between them. That tension is transferred to the stitch as it goes through your fabric. Getting the correct tension for your fabric is pretty important and I have a whole separate post lined up for that 🙂 For now…just note that they are colour coded….

Underneath each tension dial are yet more thread guides. Alot of thread guides on a serger. But then there’s alot of thread to guide! Thread guides on this machine that are directly under their alotted tension dials are left plain. The rest are colour coded with coloured dots, that relate to the relevant tension dial,  so you know which thread should be passing through…

And here is the cause of my irrational past fear. The upper and lower loopers! Upper looper (red) forms the overlock stitch ontop of your fabric. Lower looper (yellow) forms the overlock stitch on the underside of your fabric. Undeniably the lower looper is  sliiiiightly tricky to thread. The rest is a cinch, honestly!

Here’s a slightly different angle….The reason the lower looper (yellow dots and diagram) is slightly more tricky is because the lever thingy part of it (that part of the diagram on the right of the photo) is tucked right under the feed dogs/throat plate and even when fully extended, requires a little bit of slight of hand to loop the the thread around it. But that’s why it has it’s own diagram I guess. Never the less, after a couple of goes (tweezers are a MUST) you get the knack and it’s fine…

This machine, and most machines will have a threading guide on board. But I have a whole post lined up on threading too. So we will return to that. I think that’s enough on threading for now! Nearly there. How you feeling? Geeked out yet? Just a couple of bits left to see!

Back round to the side of the machine. A couple of dials and a lever…

Top dial is your stitch length. For the majority of standard stitches set between 2.5 and 3…

The big wheel is your hand wheel for your needles. Just like a standard machine. On/off switch and power source behind that. Nothing different there. In front however is the differential feed lever. This controls the rate at which the feed dogs pull the fabric through the machine and depending on the setting can either stretch the fabric out, or gather it. For normal stitching its set at 1 (in the middle). Again…separate post line up for that too 😉

Worth noting the air vents for keeping the motor from overheating. Do not obstruct whilst in use.

Then finally back to the back and a little tip. I keep a photograph of the make and model numbers of my machines on my phone. Then if I’m out and about and accidentally stumble into a haberdashery (as you do…accidentally) and want to check if a bobbin/blade/presser foot is compatible with my machine…then I can tell the store owner what my machine is…because I can never remember model numbers!

Anyway….there ends part one. Alot of images I know but hopefully useful in acquainting you with the anatomy of a serger and preparing the ground for the next few posts which will hopefully have you fearlessly serging away in no time.

Watch this space. Next up…the dreaded threading!!