Jack A4 User Manual

Mechanical adjustment-Adjustment of the hook
Turn the handwheel to make the hook tip to the center needle, and then
continue to turn the handwheel to make the needle from down to up in 2.2
2.5 mm, then to keep hook tip to above the pinhole between 1-1.2 mm, and
also the horizontal distance between needle and the hook tip is 0-0.1 mm.
1-1.2mm

Jack A4 Specifications

General

Brand	Jack
Model	A4
Category	Sewing Machine
Language	English