Lower-Thread Tension (Basic Setting) - Bernina B 590 Service And Maintenance Manual

Lower-thread tension
5.12.2
Check:
•
Use white cotton thread DMC 50 BLANC 652010.20.++ for gauging.
•
Use no. 0033924.70.00 gauge to adjust lower thread tension.
•
The bobbin case is inserted into the weight gauge in the same way as into the hook.
•
Hold free end of thread firmly and let the bobbin case and setting weight (without additional weight)
hang free.
•
The bobbin case must not move downwards.
•
After attaching an additional 3-gram weight 398142.03.0+ the
thread should unwind fast (unwinding speed: 1m/2-4 sec.).
Adjustment:
•
Use a small screwdriver to adjust the lower thread tension by
turning the bobbin case spring screw as appropriate.
•
Turn screw counterclockwise (to left) to slacken .
•
Turn screw clockwise (to right) to tighten.
BERNINA International AG
(basic setting)
Seestrasse 161 CH-8266 Steckborn
DRAFT – VERSION
1
398142.03.0
+
Schweiz Seite 116 von 172