Stitch Length - Singer 7285Q Service Manual

Service Manual

15. Stitch length

(A) Checking meshing position of gears
This procedure is needed only when disassembling and re-assembling cams.
Rotate motor gear clockwise to touch it with stopper pin and mesh these gears so that
feed regulator gear may be positioned with full two gears below line from feed regulator to
motor gear
(B) Origin point positioning of stitch length
Step motor rotates 7.5 degrees with one pulse and ratio of motor gear vs. feed regulator
gear is 1:5. This amount of rotation makes feed regulator rotate 1.5 degree. This amount
of rotation makes stitch length vary by 0.25 mm. 0.25 mm stitch pitch moves at each of 7.5
degree exciting position.
Switch
Stopper pin
Full two gears below line
Stopper pin
Switch is
turned on.
Original issue
May, 2014
26/38
Page
Model
7285Q
Projection (1)