What Do The Cutting Blades Do?
The knives also called cutting blades, are a huge part of what makes using a serger so wonderful! The cutting blades trim the fabric even before the stitches are formed. This forms a neat, finished edge.
Upper And Lower Knives/Blades
Sergers have two knives that work together like scissors to trim the fabric as the machine stitches. The upper knife is the one that looks a bit like an upside down hook in from of the needles. The upper knife moves up and down. The lower knife is usually located just under the needle plate and it stationary. On many machines, the upper knife can be disengaged for decorative sewing.
How To Adjust The knife or Blade On A Serger
Most sergers have a dial that you can turn to adjust the distant on the blade. In the video above I show you how to make adjustments on a Baby Lock Imagine and A Brother 1034D. Most sergers are going to be similar to the ones I use in the video. Always run a few test strips after adjusting the blade width to ensure you like how it looks.
When To Engage or Disengage The Blade/Knife
Engaging or disengaging the blade allows you to prevent or allow the blades to cut off the edge of the fabric as you sew. By disengaging the knives, you can serge away from the edge of the fabric, topstitch, apply elastic and many other decorative stitches.
When the blade is engaged you can determine how much fabric will be cut from the edge. Most regular serging stitches looked best when the serger is allowed to trim off at least a small amount of fabric. My favorite part of this is my projects are clean and professional looking and I don't have to go back and trim my seam! Talk about saving time.