Service-Manual_artista_630_640_english_V4.01_032069_50_04.doc
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4.22 Drive belt (synchronization of main and base shaft)
Disassembly
1. Remove
covers.
2. Loosen the two motor bracket screws (
25
) and pull
drive belt off hand wheel.
3. Remove
screw
(
46
) and belt tensioner (remove
tensioner, clean and oil idler pulley shaft).
4. Remove shaft bearing (
48
) screw (
49
). Swing shaft
bearing down, taking care not to move the bevel
gear out of mesh.
5. Slide belt tensioner out down, and remove it from
the top over the hand wheel.
Assembly:
1. Pin balance piece and base shaft. Cylinder flute
(edge) must face front (see
p. 50 CB and 52 RH
)
2. Fit new drive belt and belt tensioning pulley (note
the pinning positions.)
3. Refit the shaft bearing bracket (
48
) – 0.1-0.3 mm
play between bearing shaft and bracket. Adjust with
screw (
47
)
4. Tension drive belt – turn hand wheel back by a half
rotation, tighten screw (
49
).
5. Adjust synchronisation, (
p. 50 CB and 52 RH
).
6. Refit main motor (
p. 30
).
7. Refit
covers.
8. Calibrate speed – Service Program test 4f (
p.
84
).
9. Carry out a functional check.
10. Sew-off.
4.23 artista 630 upper thread tension
Disassembly:
1. Remove
covers.
2. Remove securing screws (
58
).
3. Replace thread tensioner (
59
).
Assembly:
1. Fit new thread tensioner and tighten securing
screws (
58
).
2. Note the position of the thread tension release.
3. Set the stitch width limiter (
73
) with screw (
74
).
4. Refit rear and front covers.
5. Set thread tension (
p. 63-
).
6. Adjust thread regulator spring (
p. 65
):
7. Check thread tension release mechanism.
(
p. 61
)
8. Sew-off.
73
74
58
58
59
46
49
48
25
47
