Thread Tension - Duerkopp Adler 558 Operating Instructions Manual

2.8 Thread Tension

Upper thread tension
The upper thread tension on the machine arm must generally be set tighter than the
underthread tension.
It is set by turning the knurled nut 6.
Tension increase
Tension decrease
The upper thread tension is executed as a dual tension:
–
Remaining rest tension 1
It serves to tauten the upper thread during the cutting procedure under the
needle plate as well as to achieve the desired length of upper thread end.
The rest tension must, depending on the elasticity of the upper thread used, be
so set that upper thread end hanging out of the needle is long enough to assure
a secure sewing start.
The setting occurs by turning the sleeve 2.
Longer thread end
Shorter thread end
If the upper thread end remains too long then work must be conducted without
tension release. This can, for example, be the case with firm and hardly flexible
upper thread.
For the appropriate settings see Service Instruction 558.
–
Main tension 5
This should be appropriately corrected after changing the rest tension.
The thread gripper 3 remains closed in the end position.
During removal of the sewing pieces this avoids a subsequent pulling of the
upper thread out of the thread tension.
For the next sewing sequence there is then always an uniformly long starting
thread available.
Subsequent pulling of the upper thread by hand
Open the thread gripper 3 by hand and subsequently pull the thread.
For this either hold the button 4 down or swing the release lever 7 down.
= turn to the right
= turn to the left
= turn to the left
= turn to the right
ATTENTION !
Do not heighten the cutting effect of the upper thread knife
by further increasing the rest tension.
To heighten the cutting effect sharpen the knife.
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