Let’s talk differential feed on a Serger.
Here is the knob.
We’re going to adjust.
Notice that it’s set at 1 when you don’t need it, so it’s kind of like a one to one
ratio.
The numbers change down to 0.7 and then it will go all the way up 2.
The 2 would be like a 2:1 ratio.
What kind of ratio are we actually talking about?
When we come over here, if you want, you can look under the foot and you’re going to
notice that you have two sets of feed dogs, two in the front and two in the back.
We sometimes need this when we stitch on fabrics that are stretchy and you get it and when
it comes out and it’s wavy, or you’re stitching on fabric that is slippery.
You’re stitching along and you’re realizing the bottom layer for example, comes out a
little on the short size because the bottom layer is gathered up and you don’t want
that.
These two items are going to show us what differential feed can fix.
Let’s go ahead and just start.
This is just a regular one to one ratio on the knit fabric.
Let’s go ahead and stitch like normal.
Look what we get.
We have the wavy edge which we don’t want, so pretty much what’s happened because this
foot is so long, the pressure of it has stretched it during the surging process.
What we are going to do is we’re going to ask the front feed dog to go get more fabric
and ease it in before the needles which are behind where the front of the foot starts
pushing down before it gets the stitch.
I’m going to go ahead, let’s see here, 2.0.
I’m going towards … I probably won’t need to, but let’s go ahead because sometimes
of a light knit, you only have to go out to 1.5.
Let’s see where we at here.
I’m going to do it on the other side, so we have something to compare it.
What’s going on here is … I love this.
Look at how flat that is.
I’m also noticing that it actually went in a little bit more than I needed.
See how it’s starting to ease in, so between 1 and 2 as in 1.5 would be just enough to
ease it in so we don’t have the waves and we have it perfectly flat.
With this of course, you still have that stretch and give, but we definitely don’t want to
start with the wave at the beginning.
Differential feed and honestly if you forget which way to go, one makes it worse, one makes
it better.
Give it a whirl both ways and you will definitely see the difference.
Fleeces, sweatshirt fabric, T-shirt knits, those are going to be the things you’re
going to notice that at.
Go back to 1 and then we’ll go ahead and just do these two slippery fabrics.
I remember working on a rayon project when I was young and I noticed that when I got
to the end, my bottom layer was actually shorter than my top layer.
We’ll just say it was on a shorter dress to start off with, so that dress was getting
smaller and smaller.
See on this back side?
Can you see, this is the underneath edge, that is starting to get a little bit puckered
where the top edge was not puckered.
What was happening is the bottom layer was being fed faster.
If you don’t want the puckers, what we’re going to do is change it to the 0.7 range.
We’ll just do it again.
You’re going to notice now that front feed dog will be not pulling in the same as the
back.
It’s actually going to be pulling in less and what it’s going to do is help hold that
bottom layer from feeding as quickly and without that extra gather.
Now it’ll be perfectly flat all the way through.
Flat and flat.
Here’s something that you might notice.
On this turquoise fabric here, did you notice that my four different colors of thread.
I’ve got the yellow, the red, the green, and the blue.
They all just blend in, so it really doesn’t show up much depending on your color order.
The only thing that I would change because I’m going to see yellow in that needle is
I would put my blue or a small spool of turquoise thread, a matching thread in my outside needle
and guess what, it won’t matter what thread is actually in the inside seam because you’re
not going to see it.
Even though there’s red right there.
Who cares?
You really can be quite forgiving.
There has been projects that I have some colorful insides with because that’s what I had on
and it wasn’t going to matter and only one needle was going to show in the seam which
I did match up.
Differential feed is definitely something to know about and be able to adjust.
Again, one makes it better, one makes it worse.
If you can’t remember the whole way it’s supposed to work, just give it a go both ways.