Thread Tension - Bernina B 590 Service And Maintenance Manual

4.3.17 Thread tension

Disassembly:
• Remove the covers (see 4.1).
• Picture 1 - Untighten screw a by 2 rotations.
Remove screw b.
• Picture 2 - Push stepping-motor carrier to right in
direction of arrow. Then lift thread tension out.
• Picture 3 -
No.
1 Rubber mount
2 Thread tension axis
3 Left tension disc
4 Centre tension disc
5 Right tension disc
6 Buffer with position retainer
7 Tension spring
8 Washer
9
10 Drive wheel
11 Spacer
Assembly:
• Picture 3 - Reassemble upper-thread tension in this
order.
• Picture 4 - Turn tension discs closed until guiding
slots match. This will make it easier to fit them onto
the guide rail.
• Picture 2 - Push stepping motor to right in direction
of arrow. Then refit thread tension.
• Picture 1 - Refit and retighten screw b.
• Picture 5 - Using distance gauge 735386.50.00,
reset to mechanical basic setting.
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