(A)
4 mm
18
104 72 63-26
Adjustment of pre-tension dial
The standard position of the pre-tension dial is as follows:
The screw head (A) should be 4 mm below the dial face.
Adjustment of bobbin thread tension
Requirement
The force required for pulling cotton thread 50/2 or synthetic fi ber thread 100/3 off the bobbin must be
approximately 20 - 30 g.
Check
• There must not be any thread waste under the tension spring.
• The tension spring must rest evenly and parallel on the bobbin case.
• When a threaded bobbin case hangs on its thread, it should not slide downwards by its own weight.
• With a quick upward movement of the hand, the thread must run off gradually.
Adjustment
• Loosen the set screw a little and turn it in again until a resistance is felt when the thread is pulled off.
• Re-check