37
The
tension discs should be pushed apart to open
when the presser foot is lifted. But the open timing of the
tension discs can be adjusted as follows: Remove face
plate and the rubber plug at rear side of arm and loosen
screw (A) of the knee lifting lever (left), then the tension
releasing cam can be moved leftward or rightward when
the cam is moved rightward, it is later to open, otherwise
it is earlier to open.
.
29. Adjusting presser foot alternate lift mechanism (Fig 37)
27. Adjusting the tension releasing mechanism (Fig 35)
35
-14-
28. Upper feed adjustment (Fig 36)
36
Right
D
During the sewing, the center gauge (L) between
the walking foot sliding block and its shaft can be adjusted
according to the differences of the friction coefficients of
the friction coefficients of materials and the sewing pro-
cess.
Method: Increase L the upper feed amount
enlarged
reduce L the upper feed amount
shorten
For special sewing requirements, for example, the
upper layer of material needs more amount than the lower
layer does, in this case, adjustment can be done in the
range of above theory for operation.
.
.
.
.
During the sewing, the alternate lift amount can
be adjusted accoding to the nature of material. In general
sewing, the amount of walking foot is 5.5mm, and the
presser foot lift amount is 3.5mm.
Method: loosen the screw A. turn presser foot
front crank upward to increase the amount of walking
foot; turn it downward to reduce the presser foot amount,
the range of adjusting amount is not too large. After
adjustment, tighten the screw.
.
.
Left
Above
Under
