Bernette Airlock b64 - 3-Thread Overlock

Sewing test
63
2020-09 EN 5040064.00A.04
4-/3-thread Overlock
With a balanced stitch formation, the Looper Thread (blue/red) are intertwined at the fabric edge.
The Needle Threads (green/yellow) create two straight lines of stitches on the right side of the stitch and
appear as dots on the wrong side of the stitch.
Stitch pattern Solution
The Looper Threads are intertwined on the
wrong side of the fabric.
> Reduce the Lower Looper Thread Tension (red).
> Increase the Upper Looper Thread Tension
(blue).
The Looper Threads are intertwined on the
right side of the fabric.
> Reduce the Upper Thread Tension (blue).
> Increase the Lower Looper Thread Tension
(red).
The Left Needle Thread forms loops on the
wrong side of the fabric.
> Increase the Left Needle Thread Tension
(yellow).
> Reduce the Lower Looper Thread Tension (red).
The Right Needle Thread forms loop on the
wrong side of the fabric.
> Increase the Right Needle Thread Tension
(green).
The fabric edge curls.
> Reduce the Upper Thread Tension (blue).
> Reduce the Lower Looper Thread Tension (red).
> Increase the mtc Mircro Thread Control.
> Reduce the Cutting Width «CW».
> Check the Rolled Hem Selection Lever position
«N».
The seam puckers.
> Reduce the Left Needle Thread Tension
(yellow).
> Increase the Right Needle Thread Tension
(green).
> Set the Differential Feed between 1 and 0.6
(Stretching).
> Shorten the Stitch Length «SL».
Tab.1: Optimizing the stitch: 4-/3-thread overlock