Basic Knee Lifter Settings (Fhs); Basic Settings Of Lower Thread Tension - Bernina aurora 430 Service Manual

Basic presser foot lifter setting (FHS)
Standard:
• The end of the knee-activated lever (FHS)
should be approx. 160 mm from the
needle center position (horizontally).
Note! This can be set to suite the customer.
Correction:
• Attach lifter in opening 110.
• Loosen screw 109.
• Position lifter appropriately.
• Retighten screw 109.
Checking correct position:
• Raise lifter lever.
• Set upper thread tension to 10.
• When the lifter is actuated, the lifter lever
must drop.
Correcting the position:
• Loosen securing screw and turn
adjustment eccenter 111 until the lifter
lever drops.
• Check tension release mechanism. Correct
if necessary (lever must be free).
Basic setting of lower thread tension
Standard:
• Use Mettler no. 60/2 Nm 43.1/2 white
thread.
• Use no. 001 538 70.00 gauge to adjust
lower thread tension. The bobbin case is
inserted into the weight gauge in exactly
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 weight (5 g,
no. 398 117 030) the thread should
unwind fast (unwinding speed: 1m in 2-4
sec.). If you test with darning thread, the
unwinding speed is 1m/25 sec.
Correction:
• Use a small screwdriver to adjust the
lower thread tension by turning the
bobbin case spring screw as appropriate.
Note:
• Turn screw counterclockwise (to left) to slacken
• Turn screw clockwise (to right) to tighten.
109
111
79
110