In the old days we gathered fabric on our sewing machines by pulling bobbin thread, zigzaging over floss and a whole host of other stand on your head tricks. But with sergers today you can easily gather fabric either on the edge (with a 4 thread) or down the center (with a 5 thread). How U do dat?
First of all adjust the needle thread tensions to a higher number. For example if 3 is normal for your serger - set both needle tensions at 6 or 7, adjust the stitch length to as high a number as you can. Lastly adjust the differential feed to the highest number you can. For some sergers that means adjusting the stitch length to 4 or 5. The differential feed settings differ from model to model. So if 2 is the highest number on the dial - than that's the number for U.
Of course several sewing machine companies that carry sergers offer a "gathering foot" or "gathering attachment" for sergers. I can tell you from experience - THEY WORK GREAT!!!! The gathering is uniform and neat. (Don't worry about the stitches on the edge looking loopy - they are supposed to.)
How do you know how much the fabric will gather? Well - here is one way to judge. Take a 10" scrap of the fabric you will be using for the project (garment) and gather it. Then run to the yardstick or cutting table if you have one and measure and see what you have left. Let's say you have 5". Well you know how to calculate now. One teacher I had said start with 12" - yeah that would work if I had paid more attention in math class. Did not. I was too busy flirting with all the boys. I was a teenager in the 60's - enough said.
Everyday I am grateful to the person that invented the calculator. Thanks!
If you scroll down you will see a little girl's dress I made with a ruffle at the hem That is exactly how I did it. Go take a look.
Happy Velentine's Day everyone!