Adjusting The Needle Clearance; Adjusting The Shuttle Race Thread Guide; Rotary Hook Lubrication Amount - Brother BAS-311H Service Manual

8. ADJUSTMENT

8-7. Adjusting the needle clearance

3059B 0138Q
Turn the pulley (1) in the direction of the arrow to align the tip of the rotary hook with the center of the needle, and then loosen
the set screw (2) and turn the eccentric shaft (3) to adjust so that the clearance between the needle and the rotary hook is 0.01
to 0.08 mm.

8-8. Adjusting the shuttle race thread guide

Install the shuttle race thread guide (1) by pushing it in the direction of the arrow so that the needle groove is aligned with the
center of the needle plate hole.
NOTE:
If the shuttle race thread guide is in the wrong position, thread breakages, soiled thread or tangling of the thread may
occur.
The position of the shuttle race thread guide is adjusted at the time of shipment from the factory. It should not be changed if
possible.

8-9. Rotary hook lubrication amount

More oil
Less oil
89
Aligned
0.01 to 0.08 mm
(for medium-weight and
heavy-weight material
specifications)
0.1 to 0.2 mm
(for seatbelt specifications)
The optimum position is when the head of the set screw (1)
is aligned with the edge of the bed. The rotary hook
lubrication amount can be adjusted within three turns to the
right from that position.
･
If the set screw (1) is turned clockwise, the lubrication
amount becomes smaller.
･
If the set screw (1) is turned counterclockwise, the
lubrication amount becomes greater.
3127B
BAS-311H
3378B
3574Q