What To Look For When Buying A Serger:
You know, if you buy a cheap serger from a box store, you will be very frustrated. So don't! What is the difference? "Tolerance."
When a machine is manufactured, the manufacturer sets a tolerance level. "Low tolerance," means they don't tolerate any sloppiness in the manufacturing process. A "low tolerance" factory will make a quality machine. The metal has to meet a certain quality. The parts have to fit together tightly, without any "play." You can detect a serger that's made in a "high tolerance" factory (where they allow sloppiness), by grabbing the needle bar and see if it will wiggle forward and backward. If it wiggles forward and backward, we can't set the needle/looper distance (a timing setting), because it's variable. If the metal is cheap, the screws strip, and the parts wear out quickly. It then becomes a disposable machine. When you take a cheap machine in for a repair, we don't have much to work with. Sometimes we will tell you it isn't worth the cost of having it repaired, because we CAN fix it, but it won't STAY fixed.
Three features that you really want on a serger are 1) a built-in rolled hem, 2) differential feed, and 3) a tall thread rack.
#1 The rolled hem is such a great way to finish a raw edge. You can use it to finish the edge of a ruffle, instead of folding it in half. You can finish table linens or anything else that you don't want to put a hem on. On most machines, there's a switch in the front that's pushed forward for regular serging, and pulls back for a rolled hem.
#2 Differential feed means that you have 2 feed dogs. The front feed dog goes the same speed all the time. The back feed dog can be adjusted to go faster or slower. So, if you're sewing on a stretchy fabric, and you don't want it to stretch out and be wavy, you can slow down that back feed dog. However, if you do want it to stretch out and make a "lettuce leaf edge," you can make the back feed dog go faster. Also, if you're sewing with a non-stretchy fabric, and you want to gather it up a bit, you can slow down the back feed dog, and it will gather it. You'd need a gathering foot to get deep gathers, though.
#3 A tall thread rack may seem like a little thing, but the taller the thread rack, the nicer the thread feeds off of the spool. And it is sooooo important for the thread to feed well off of the spools. If it doesn't feed well, where the threads are supposed to lock on the edge, will wave.
I'd like to show you a few things about serger repair.
Here's a common problem we see with sergers. There are 2 pins in the needle plate that hold the fabric stable as the stitch is formed. Sometimes they get bent or broken off. Sometimes you can bend the bent pin back in place. The pin on the left is too bent, and will have to be replaced. The pin on the right is broken off, and will also have to be replaced. Some sewing machine mechanics are willing to replace these pins, others will just have you buy a whole new needle plate.
I worked on this serger a couple days ago. The woman says she sews on flannel every day. If you'll look closely at the needle plate, you can see that the center support is broken out and pokes up in the front. And the support between the pins is broken and pushed down. The cause of the break is the amount of lint that's packed into the feed dogs. WOW! That's a lot of lint!
|You can click on the image to get a closer look.|
Moral of the story... it's a great idea to remove the needle plate, and clean out the lint every once in a while.
|In this picture, the thread puller is knocked out of position.|
|Here, I've loosened the black screw, and moved the arm so it's even with the looper arm behind it, then re-tightened the screw.|
When sergers sit unused for a long time, the old oil will turn into a gummy mess. So, if you can't turn the handwheel, that usually means you have a gummy mess inside. Then we have to remove the old oil with a "solvent," remove the solvent and whatever it disolved, then re-oil.
To prevent this from happening to your serger, just get it out and use it every month.
This poor serger! Its owner should be reported to the sewing machine abuse council!
Strike 1: Bad thread.
Strike 2: The thread rack is on backwards -- the thread needs to pull straight up off of the cone.
Strike 3: The far left spool pin is broken off.
Strike 4: The pad under the spool pin is falling apart.
Strike 5: The thread puller is out of position.
This is a great serger! We'll just clean it up and it will run like new.
After its been cleaned and oiled, we'll put the thread puller back in place.
Then we need to repair the spool pin. I cut a spool pin off of another machine that was in the "bone yard."
I used a Dremmel to make a hole through the bottom of the base. Then I used the Dremmel to hollow out the spool pin.
Select a screw that will stick up about 1/2" past where the old spool pin broke off. Make sure the screw and hollow spool pin with fit together nicely.
Mix up some 5 minute epoxy, and put it inside the hollow spool pin. Screw the new spool pin on, and let it sit until hardened. Clean up any excess glue.
Not a very good picture, but you can see the position of the thread rack. It even has a sticker on it that tells which side should go towards the front.
Didn't have time to take more pictures, but it sewed-off beautifully!
Skipping Stitches and Tension
(A reply to Anne B. that may be helpful to someone else.)
The first thing we need to check when a machine is skipping stitches, is the needles. Have you put new needles in? And are they pushed all the way up? When pushed all the way up, the needle on the right will be a little longer than the needle on the left. Some Singer sergers take a very specific needle. Go wherever Singer needles are sold, then look for the serger needles. They’re different from other brands because the top of the shank is very small. Use a size 75 to 90 needle.
The next thing to check is the needle guard. This is under the needle plate and is like a shield on both sides of the needle (front and back). Do the needles hit the needle guard? That’s something you can adjust.
Then make sure there are no burrs or damaged needle plate pins.
If you’ve checked all of this, and you’re still skipping stitches, it’s time to take it to the shop to have the timing adjusted. That’s something you don’t want to try yourself. If you scramble the timing, it would be a disaster.
It sounds like the Juki’s timing is waaay out, or it has the wrong needles in it. The older Juki’s also take a very specific needle, the BLx1. The newer Juki’s take a regular Schmetz or Bernina 130 705H. Use a size 75 to 90 needle.
The timing settings on a serger are quite complicated. #1. The needle bar has to be the right height. #2. The lower looper has to take the thread off the back of the needles, and hit just above the needle eyes. #3. The upper looper has to take the thread off the front of the needles, and hit just above the needle eyes. #4. The loopers have to be very close, but not touch, and the lower looper has to cross behind the upper looper, just under the bump. #5. Both loopers need to come very close to the needles, but not touch. #6. The feed dogs need to be going down at the same time the needles are just about even with the needle plate. #7. The cutting arm needs to be in sinc with the feed dogs.
As for the tensions, you’ve got to start with a good thread. A couple that we’ve had trouble with are Mediera and Guterman. There’s also some that comes on a very big cone, and is very stiff (don’t know the brand). If you use Maxilock, you’ll always get your best stitch. Then make sure the thread is pulling straight up, off of the cone. The easier it comes off of the cone, the better your stitch will be.
Turn the tension dials to zero, then blow them out with an air compressor or canned air. Then put them all on 3, and start adjusting them by how your stitch looks.
Start with the needle tensions. They are the straight lines on the back of the fabric. If they’re looping, tighten the tension. If they’re pulling too tight, loosen them.
Then work with your loopers. You want the ridge, where the stitches lock together, to be balanced on the edge of the fabric. If the ridge is coming tightly to the front, loosen the front. If it’s coming loosely to the front, tighten the back. If it’s coming tightly to the back, loosen the back. If it’s coming loosely to the front, tighten the back.
I hope there’s something here you can use.
Here's some pictures in reply to serger timing.
There’s a bolt/screw at the bottom of the lower looper that holds it onto the shaft. If you loosen it, you can move the whole arm.
The lower looper should pass behind the needles and the tip should be just above the eye of the needles.
|The loopers should only have a tiny space between them, but they should “nest” together.|