Main Shaft And Synchronizing Disc - Bernina aurora 430 Service Manual

66

Main shaft and synchronizing disc

Disassembly:
1) Remove covers.
2) Remove P-Print (see page 55).
3) Remove securing screws 73 and 74 from
balance piece.
4) Remove motor drive belt.
5) Remove base shaft timing belt.
6) Remove screws 79a and clamps, along
with circlip 76.
7) Pull complete main shaft off balance
piece. Move belt off base shaft.
8) Replace any shaft parts or the shaft itself
if necessary.
Assembly:
1) Assemble main shaft with plastic washer,
steel washer, spherical bearing, steel
washer, plastic washer, setting collar 75,
circlip 76, synchronizing disc 77, spherical
bearing with screw 77a and drive belt
flange 78).
2) Position balance piece in such way that
the thread take-up lever faces the front.
3) Insert main shaft through base shaft
timing belt and into balance piece.
4) Insert spherical bearings into their sockets
and secure with clamps 79.
5) Position the main shaft into balance piece
in such way that the marking on the take-
up link can be seen. Tighten balance piece
screws 73 & 74.
6) Place adjusting collar against balance
piece so there is no play and tighten
screws.
7) Position synchronizing disc (see page 23)
and secure.
8) Pin balance piece.
9) Remove main motor bottom screw.
Loosen top screw, swing motor up and
secure.
10) Pin hook drive crank.
11) Place base shaft link belt and tighten.
79a 79
75a
12) Retighten drive belt flange.
13) Place drive belt and tighten it (see page
67). Secure motor.
14) Attach front cover.
15) Refit P-Print.
16) Connect L-Print.
17) Connect machine.
18) Set synchronizing disc in service
programme "Positioning" (see page 23).
19) Refit covers.
20) Calibrate speed (see test programme no.
6.1 page 33).
21) Carry out a functional check.
22) Sewing-off.
76 77 77a
75
73
78
78a
79
79a
74