– 17 –
Adjustment procedures
Results of Improper adjustment
1. Turn the pulley to rise the feed dog to the highest point.
2. Loosen the screw
❶
. and move the main feed dog
❷
up and
down in order to keep the teeth side over the throat plate about
0.9 to 1.1 mm (30P : 0.7 to 0.9 mm, 60H : 1.0 to 1.2 mm). Then,
tighten the screw
❶
.
3. Loosen the screw
❸
. Move differential feed dog
❹
up and down
to adjust so that it is flush with the main feed dog
❷
. Then, tight-
en the screw
❸
.
4. The teeth section of the auxiliary feed dog
❺
has to be positioned
lower than the main feed dog
❷
by 0.3 to 0.5 mm (30P : 0.1 to 0.3
mm, 60H : 0.25 to 0.35 mm). The height of the auxiliary feed dog
❺
can be adjusted by loosening the screw
❻
.
o
If the feed dogs are too high,
the needles will be deflected
and broken when sewing heavy-
weight materials. The feed dogs
will tend to suffer scratches
when sewing light-weight mate-
rials. Puckering will frequently
occur.
o
If the feed dogs are too low, in-
sufficient feed power will result.
o
If the auxiliary feed dog
❺
is
too high, chain-off thread will be
often jammed.
o
If the main feed dog
❷
and
differential feed dog
❹
are set at
different heights, proper differen-
tial feeding action will be hin-
dered.
Adjustment procedures
Results of Improper adjustment
1. Loosen screw
❶
and turn rear support shaft
❷
.
2. When the feed dog is flush with the top surface of the throat plate
and the feed dog is levelled (30P : The feed dog is positioned
with its front part low), tighten screw
❶
.
o
When tilted with the front up ;
Good material catching will be
obtained.
o
When tilted with the front down ;
Uneven feed and puckering will
be effectively prevented.
