Bernina B 590 Service And Maintenance Manual page 59

• Picture 5 - Insert the setting hook including gauge
shaft 734591.70.00 and fitted pressure spring into
hook race ring. Then slide the 5.0mm thick end of
gauge shaft through the hook race bearing up to
stop. Secure gauge end using the plastic knurled
nut. It must now be possible to compress the
gauge shaft to check for smooth running.
• Align gauge shaft bracing horizontally. Check if
hook race ring is properly centred by briefly
pressing the gauge shaft. The gauge shaft must be
pushed back by the spring automatically.
• Picture 4 – Slightly retighten the three screws 2 of
hook race ring 1 => 2 => 3. Then retighten
completely in this order: 1 => 2 => 3
• The hook race ring is now locked in all directions.
• Align gauge shaft bracing vertically. Check if hook race ring is properly centred by briefly pressing the
gauge shaft. The gauge shaft must be pushed back by the spring automatically
Note:
If the gauge shaft is pushed back by the spring automatically, the z-axis setting of the hook race
bearing is fine. Repeat this procedure 3 times.
• Insert the hook drive in its neutral position in such way that the drive
belt can be loaded onto the gearwheel using spring mounting tool
398112.03.0+. The flat side of the hook drive shaft is opposite the hook
drive securing screw 8. With screw driver T8 put race securing screw 8
back into place without fixing it.
• Position circlip 235020.53.++ onto hook magnet. Then insert hook.
• With the left hand and simultaneously, press hook into hook race and
hook driver up to stop.
• With screw driver T8 retighten hook race securing screw 8.
• Remove hook. Then remove circlip 235020.53.++ from hook.
• Refit hook.
Note:
It is necessary to use the distance gauge 734956.50.00 with the
distance 1.025mm.
Check:
• Picture 6 - The hook drive shaft end protrudes
ca. 4.5mm from the hook bearing.
Use 3.0mm pin b to lock hook drive in loop lift
position.
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