Bernette b68 AIRLOCK - 3-Thread Overlock Wide (LN); 3-Thread Overlock Narrow (RN)

Sewing Test
78
2022-05 EN 50400685.00A.04
Stitch Formation Measures
The seam puckers.
> Reduce LN-thread tension (yellow).
> Reduce RN-thread tension (green).
> Set the differential feed between 1 and 0.6 (stretching).
> Reduce the stitch length SL.
3-Thread Overlock Wide (LN)
Stitch Formation Measures
Looper threads (red/blue) form
loops on the bottom side of fabric.
> Reduce LL-thread tension (red).
> Increase UL-thread tension (blue).
Looper threads (red/blue) form
loops on the top side of fabric.
> Reduce UL-thread tension (blue).
> Increase LL-thread tension (red).
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 UL-thread tension (blue).
> 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.
3-Thread Overlock Narrow (RN)
Stitch Formation Measures
Looper threads (red/blue) form
loops on the bottom side of fabric.
> Reduce LL-thread tension (red).
> Increase UL-thread tension (blue).
Looper threads (red/blue) form
loops on the top side of fabric.
> Reduce UL-thread tension (blue).
> Increase LL-thread tension (red).
Needle thread (green) forms loops
on bottom side of the fabric.
> Reduce LL-thread tension (red).
> Increase RN-thread tension (green).
The fabric edge forms a tunnel or
curls.
> Reduce UL-thread tension (blue).
> Reduce LL-thread tension (red).
> Increase the mtc micro thread control.
> Reduce the cutting width CW.
> Check the rolled hem selection N/R position.