Sewing Blog

How to Use an Overlocker Machine: A Guide to Your Serger Differential Feed

There’s nothing like knowledge to defeat fear and I know for sure that many sewers are actually scared by learning how to use a serger.

Let’s explore one of its most interesting features: the differential feed!

Serger Pepper - All about differential feed - Craftsy

But, first: what are the feed dogs?

Feed dogs are those thin spiky metal bars you can find right below your presser feet.

They move the fabric toward the back of your sewing machine and/or serger, under the needle, determining the exact length of your stitches.

They can also move the other way, doing what we call “backstitch” (although I wouldn’t suggest you to backstitch on your serger!).

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The differential feed system

Looking at your serger needle plate, you'll notice two independent sets of feed dogs: one front, the other one rear.

Serger Pepper - Differential feed dogs - Craftsy

Each one has an individual feed mechanism: they will be able to feed the fabric at a different ratio (but you can also make them move at the same speed, if that's what you need!).

The differential feed knob/lever has a numbered scale, usually going from 0.6 (or 0.7, like mine) to 2, where:

  • From 0.6 to 1 (negative differential feed) the front feed dog doesn't move as much as the rear feed dog, causing the fabric to stretch under the presser foot to offset the puckering;
  • 1 (sometimes labeled as N - neutral differential feed) both feed dogs walks at the same speed;
  • From 1 to 2 (positive differential feed) the front feed dog moves more than the rear feed dog, amassing fabric under the presser foot (when set at 2 it actually makes twice as many rotations of the rear one!)
Differential feed lever- Craftsy

To help visual people like me, most sergers comes with two little graphics next to the numbered scale, meaning stretched (0.6) and gathered (2) fabric.

Troubleshooting

If you're sewing a medium weight woven fabric, 99% of the times your differential feed will work just fine set on 1.

If you sew other kinds of fabric, you may need to adjust the differential feed to achieve a pucker-free or waver-free seam, laying flat.

Note: Always try on scraps to decide the ideal settings, paying attention to keep grains, bias and stretch directions consistent with your project!

  1. If you're sewing a sheer, lightweight or slippery fabric, you may experience puckering.
Differential feed on lightweight woven - Craftsy

How to fix it:

Decrease your differential feed ratio until you get a flat seam.

  1. If you're sewing knit, stretch, or even woven fabric cut on bias, you may stumble upon a stretched wavering seam.
Differential feed on knits - Craftsy

How to fix it:

Increase your differential feed ratio until you get a flat seam.


Differential feed: Creative uses

Differential feed >1

Gathering

Since using settings above 1 will cause your front feed dog going faster than the rear one, you can easily create gathering with a 4 thread overlock, just increasing needles' tension.

Experiment on scraps to see how much you are able to gather your fabric:

  • If it's not enough ruffled, pull the right needle thread to increase gathering;
  • If it's too full, just pull the fabric to make it looser.
Gathering with the serger differential feed - Craftsy

Easing

Another practical way to use positive differential feed, is using it to ease in: think to fit a sleeve head into an armscye or sewing a rounded hem.

Remember you need to put the fabric to be eased in against the feed (to learn more good tips like this one, check Janet Pray's "Sew Better, Sew Faster" classes!)

Differential feed <1

Lettuce edge

Since using settings below 1 will cause your front feed dog going slower than the rear one, you can easily create a lettuce edge on a stretch knit (use narrow hem settings and learn more with Angela Wolf's "Creative Serging Class"), creating that fun wavy look!

serger differential feed

If you're in the market for a serger, I would suggest you buy one with this feature, but what if your old/inherited/second-hand one doesn't have a differential feed and you're experiencing unwanted wavering on knits (or puckering on sheers)?

You can mimic the differential feed with your right hand in front of the presser foot, gently pushing (positive differential feed) or holding (negative differential feed) the fabric while it feeds through the needle, just as you would do with a regular sewing machine.

If all else fails: the stitch length and the foot pressure can influence the waviness/puckering of the fabric.

Play with those settings until you get the best result, while you're testing your settings!

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36 Comments

Cucicucicoo

Great and useful article! 🙂 Lisa

Reply
Irene V. (MammaNene)

Thanks Lisa!

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Sandra

Very usefull and clear, thanks:-D

Reply
Irene V. (MammaNene)

Happy to hear you liked it, Sandra!
I enjoyed writing it and I’m using my differential feed even more 😉

Reply
Carrie

Very well written!

Reply
Irene V. (MammaNene)

Thanks Carrie… I’m blushing!

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Sheryl Ball

Great article! I’ve never changed the settings on my differential feeds so now I will need to experiment! Thanks!!

Reply
Irene V. (MammaNene)

I’m happy to hear you’re going to experiment with it, Sheryl. Please ask if you think something wasn’t working as expected, I’ll do my best to help you!

Reply
Wendy Cookson

Great tutorial, very well explained!

Reply
Irene V. (Serger Pepper)

Thanks Wendy!
I’m flattered by your sweet words 🙂

Reply
Kiran Makkar

Very nice article. Very easy to understand. It is a great effort indeed, Irene.

Reply
Irene V. (Serger Pepper)

Thanks Kiran!
I think I have a love relationship with my serger and I my mission is getting people love it like I do!

Reply
PJH

This is the best article I have ever read about sergers!
I hope this group continues as I will be looking forward to more of the same.

Reply
Irene V. (Serger Pepper)

You’re so nice PJH!
I hope you will enjoy my next ones too… because there are many more coming, for sure!

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Beatriz Azuara

A great item, love it as explained, is very well written and understood even wonder to me that I have yet overlock, but has been very easy to understand.

Reply
Irene V. (Serger Pepper)

Thanks Bea <3

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Robyn

Amazing Article! It actually has helped me understand my serger better!

Reply
Irene V. (Serger Pepper)

That’s lovely, Robyn!
A lot of people is scared by her serger… but there’s no reason!
Sergers are good friends to love, not bad enemies to fight.

Reply
A Flowy and Flowery T-Shirt Dress Refashion - Cucicucicoo

[…] for their sewing blog! (Wow! Go you, Irene!) Her first post was published there just yesterday on differential feed on overlock machines, so you should go take a look at it if you have a serger. Irene is probably the most […]

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Tutorial: Refashion di un vestito e una maglietta - Cucicucicoo

[…] scrivendo sul loro blog di cucito! (Wow!) Proprio ieri si è pubblicato il suo primo post sul trasporto differenziale sulla macchine tagliacuci, quindi dovresti leggerlo se hai una macchina così. Irene è anche probabilmente la persona più […]

Reply
Caro

What a wonderfully written tutorial! Thank you, Irene

Reply
Irene V. (Serger Pepper)

Oh, Caro!
You’re so nice, thanks for reading it and appreciating it <3

Reply
Roberta

Thank you for this informative article. It is uncommon to read articles that are strictly about sergers. I hope to see more.

Reply
Irene V. (Serger Pepper)

You will see more and more articles about serger… they’re my obsession 😉
Thanks Roberta!

Reply
Louise

Very good tutorial! I just purchased a new serger, wanting to learn all I can about using. Looking forward to more serger tutorials

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Leigh

Thank you so much – this info is very helpful, and clear. I will try it today !

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Charlotte Trayer

Very helpful and informative article! Great for those of us who have owned and used sergers for years without really figuring out how–or being confident enough–to do something other than straight serging! Thank you!

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Billie wood

Very helpful 🙂 thank you

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Lynne Campbell

This article was extremely well written! I have worked at a sewing store for 13 years and have taught folks how to use their serger so I know what you said to be absolutely true but I mostly wanted to see how you verbalize the descriptions without confusing inexperienced users. That, I know, is a very difficult task which you accomplished with flying colors! Take a bow!

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Margie Campbell

Nice information, Thanks!

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Casey

Thank you for pitting your time into helping people it means alot! People lie, you need to get recognition for helping people in this world that’s what its all about
Thanks
Casey
Oh can you tell me how the stitch finger works and is it important for some things or different material Im still not sure what it does. Thanks again

Reply
J

Thank you so very much for this article! I’ve tried numerous times over the years to understand differential feed and just couldn’t fully grasp it until now. Other articles I’ve come across, including my machine manuals, present it as if you already know all there is to know and just give subtle hints on how to use it for fancier things, so I was only able to get an idea of the concept but never a real understanding. They never explain HOW it works or truly explain WHEN to use. All these years, I knew it had something to do with the way the layers of fabric moved over the dogs but that’s it. Never anything about the numbers and how they affected the outcome.

You did so beautifully, coherently, straight forward, simply. Exactly what this self taught sewer needed to finally understand what is not a complicated process but, due to how others explained it, seemed so complicated. Thank you. 🙂

Reply
Taslim Tamboli

I really liked it and it’s helpful too 👍 Thanks for providing this article

Reply
S.RAMESH TIRUPUR INDIA

VERY USE FUL GUIDE LINES FOR BEGINERS.
THANKS

Reply

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