26
4.8 Setting the retaining spring of the hook thread
The retaining spring (1) holds the hook thread after having
performed the trimming. It is to be set in such a way that the
force necessary for pulling out the thread from the retaining
spring (1) is approximately equal to the force necessary for
pulling out the thread from the hook.
Caution! Danger of injury!
Switch off the main switch! Before starting the setting
operation, wait until the motor stops!
- Shape the retaining spring (1) in such a way that it fits close
with all its surface (without wedge) onto the moving trim-
ming knife (3).
- Shape the retaining spring in such a way that it fits close, with
the slightly tightened screw (2), onto the moving trimming
knife without any pressure.
- Tighten the screw (2), until the necessary force for pulling the
thread from the retaining spring is attained. The pulling force is
tested using a screwdriver (4) according to the illustration.
Caution!
The setting of the retaining spring (1) depends on
the setting of the hook tension and differs then
according to the respective sewing category.
The adjusting screw (2) should not be screwed in in such a
way that the retaining spring gets over the perimeter of the
moving trimming knife.
4.9 Setting the switching of electromagnets
The electromagnets of the trimming device and loosening of the
tensioner must work in accordance with the diagram. This is
ensured by setting the stopmotor (see the instructions for use of
the stopmotor).
1- 1. position of the needle (225
°
on the handwheel)
2- 2. position of the needle (64
°
on the handwheel)
3- position of stopping the tensioner (10
°
÷ 25
°
on the hand-
wheel)
4- movement of the pickup roller
5- current of the trimming device electromagnet
6- current of the tensioner loosening electromagnet
5. Material trimming
5.1 Setting of the eccentrics (basic)
for the knives A and C
For the knives A and C, the mutual orientation of the
eccentrics (2, 3) should be such, so that their counterweights
are in alignment (this refers to the largest possible stroke of
the knife = 2,4 mm).
Caution Danger of injury!
Switch off the main switch! Before starting the
setting operation, wait until the motor stops!
3
2
1
3
1
3
1
2
4
5
6
1
3
2
4
2
3
