Bernette b68 AIRLOCK - 2-Thread Wrapped Overlock Wide (LN)

Sewing Test
81
2022-05 EN 50400685.00A.04
Stitch Formation Measures
The fabric edge doesn't curl as
intended.
> Increase the cutting width CW.
> Increase LL-thread tension (red).
> Increase UL-thread tension (blue).
> Reduce the stitch length SL.
> Check the rolled hem selection N/R position.
Upper looper thread (blue) wraps
fabric edge too tightly.
> Reduce UL-thread tension (blue).
> Reduce the stitch length SL.
Lower looper thread (red) not
straight along the needle thread.
> Increase LL-thread tension (red).
> Increase RN-thread tension (green).
The seam puckers.
> Set the differential feed between 1 and 0.6 (stretching).
> Reduce LL-thread tension (red).
> Reduce RN-thread tension (green).
> Reduce the stitch length SL.
Needle thread (green) forms loops
on bottom side of the fabric.
> Increase RN-thread tension (green).
2-Thread Wrapped Overlock Wide (LN)
Stitch Formation Measures
Looper thread (red) wraps fabric
edge too loosely.
> Increase LL-thread tension (red).
> Reduce the mtc mircro thread control.
> Increase the cutting width CW.
Looper thread (red) wraps fabric
edge too tightly.
> Reduce LL-thread tension (red).
> Increase the mtc micro thread control.
> Reduce the cutting width CW.
> Check the rolled hem selection N/R position.
Needle thread (yellow) forms loops
on bottom side of the fabric.
> Reduce LL-thread tension (red).
> Increase LN-thread tension (yellow).
The fabric edge forms a tunnel or
curls.
> Reduce LL-thread tension (red).
> Increase the mtc micro thread control.
> Reduce the cutting width CW.
> Check the rolled hem selection N/R position.
The seam puckers.
> Reduce LN-thread tension (yellow).
> Set the differential feed between 1 and 0.6 (stretching).
> Reduce the stitch length SL.