5-19.Button Clamp Installation; 5-20.Elevation Amount Of Button Clamp; 5-21.Feed Timing; 5-22.Clutch Lever - Brother CB3-B917 Service Manual

5. ADJUSTMENT

5-19.Button clamp installation

Place the button on the button clamp and set the scale of the
horizontal feed and the vertical feed to the distance between
the buttons. The needle should be centered over the button
holes.

5-21.Feed timing

Contact
Adjust the feed cam so that the index on the feed cam is
aligned with the cam positioning pin when the machine is in
the stop position.
5-23.Braking force
Brake shoe
Set screw
39
Button clamp
513s
Cam positioning pin
Mark
Cam positioning pin
423s
Clutch body
Brake lever shaft
516s

5-20.Elevation amount of button clamp

The distance between the upper part of the feed plate and the
tip of the button clamp should be 13 – 14 mm.

5-22.Clutch lever

Clutch lever
Adjust the clutch lever base so there is a 0.5 to 1 mm gap
between the clutch lever shaft and clutch when the machine is
in the stop position.
1. While pushing the clutch body down, turn the machine
pulley two or more complete turns in the direction of the
arrow.
2. Loosen the set screw at the lower part of the clutch body.
3. Turn the brake lever shaft until the brake shoe is at its
lowest position.
4. Tighten the set screw to secure the brake lever shaft.
* If the brake is grabbing at low temperatures and low
operating speeds and causing the machine to stop before
the correct stopping position, it might be caused by one of
the following problems. In such cases, raise the position of
the brake shoe in step (3.) above.
Work clamp lift amount is too small
Thread is not being trimmed
CB3-B916A/B917A
Button clamp regulating plate
Button clamp
13 – 14 mm
Feed plate
514s
0.5 – 1 mm
Clutch lever base
515s