Knee Lifter Unit (Accessory); Lower Thread Tension - Bernina activa 125 Service Manual

42 Basic adjustment to the knee lifter lever
(Available as a special accessory)
Standard:
The end of the knee lifter should be vertical under the
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right edge of the LCD.
Correction:
Loosen the screw 109 of the feed-dog drop unit.
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Insert knee lifter lever 110.
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Adjust the lifter to the convenient position.
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Tighten the screw 109.
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Checking the release of the lifter lever:
Place the lifter lever in its highest position.
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Turn the upper tension dial to no.10.
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When the knee lifter is actuated, the lifter lever must
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drop down.
Correction:
Turn the adjustment nut 111 until the lever drops down.
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Check the tension release mechanism and if necessary
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correct (lever must be free).

Lower thread tension

111
Standard:
For testing use Mettler white thread (BW Ne 60/2 resp.
NM 43.1/2). The lower thread tension is checked with the
moveable setting weight No. 006 543 7001. The bobbin
case is placed in the weight gauge just as in the hook.
Hold the free end of the thread and suspend the bobbin
case with the setting weight (without any additional
weight).
The bobbin case must not move downwards. After atta-
ching an additional weight (5 gr.) the thread should move
downwards (speed 1m/2 – 4 sec.). If you test with darning
thread the speed should be 1m/25 sec.
Correction:
Regulation of the lower thread tension is made with the
bobbin case adjusting screw and a small screwdriver.
Anti-Clockwise = weaker
Clockwise = stronger
110
109
right
left