Brother BAS-342G PS, Service Manual

Page: 107 / 152

7. ADJUSTMENT
98 BAS-342G
7-16. Adjusting the thread trimmer cam position
1. Remove the top cover.
2. Loosen the two set screws (1), and then adjust the
position of the thread trimmer cam (3) so that the
distance between the edge of the collar shaft (2) and the
edge of the thread trimmer cam (3) is 0.2 - 0.5 mm. After
adjusting, tighten the two set screws (1).
7-17. Belt tension adjustment
<X-GT belt>
1. Provisionally tighten the four bolts (1) and the two bolts (2).
2. Tighten the M6x30 bolt, and then pull the X pulley bracket (3) to adjust the tension.
3. Fully tighten the four bolts (1) of the X base plate (4) and the two bolts (2) of the X pulley bracket (3).
4. Remove the M6X30 bolt.
5. Move the X base plate (4) to the left edge.
6. Use a tension gauge to measure the tension at the middle of the lower belt while referring to “Measurement position” in
the illustration. (Refer to “6-5-2. X-feed mechanism” for details on measuring the tension.)
*
Check that the value for the belt tension is within the following value ranges. If it is not within this range, repeat steps 2 to 6.
[For a new belt: 650 - 750 N; For a reused belt: 520 - 600 N]
* The belt tension gauge should be set to measure a unit weight of 0.04 kg/m, a belt width of 50 mm and a span length of
485 mm.
* It is recommended that you use the Yunitta U-505 tension gauge.
1386B
4685Q
Microphone
position
Finger pressing
position
[Measurement position]
Middle of belt