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3.7.8.3 Setting the gear clearance
In the cone gear of the drive of the top roller foot, the minimum
clearance must be set. A too small clearance will increase the
friction resistance of the gear, the excessive clearance will
influence the inaccuracy of feeding. The top roller itself is
mounted on balls. With this type of mounting,it is also
necessary to set the minimal possible radial clearance.
The given clearances are set as follows:
Caution! Danger of injury!
Switch off the main switch! Before starting the setting
operation, wait until the motor stops!
- Loosen and unscrew the screw (1).
- Remove the top roller from its holder (2).
- By screwing the screw (3) against the pin (4) set the minimum
radial clearance of the wheel (5) (it must turn easily with
minimum clearance).
- Put two washers (6) on the pin (4).
- The pin (4) with the top roller is to be inserted into the hole of
the holder (2).
- Screw in and tighten the screw (1).
- If there is not the least required adjustable clearance in the cone
gear, repeat the above procedure in using the necessary number
of washers (6).
3.7.8.4 Replacement of the top roller
When replacing the top roller, proceed as follows:
Caution! Danger of injury!
Switch off the main switch! Before starting the setting
operation, wait until the motor stops!
- Unscrew the screw (1).
- Unscrew the screw (3) with the washer (2).
- Remove the driven top roller with the holder (4) from the holder
(5) and from the articulated shaft (8).
- Mount another top roller in inverted procedure to dismantling.
- Set the top roller according to the par. 3.7.8.2.
3.8 Setting the presser foot lift
The maximum lift of the presser foot when lifting the foot with
knee lever or with electromagnet is to be A = 12.5mm ±
0.7mm.
Caution! Danger of injury!
Switch off the main switch! Before starting the
setting operation, wait until the motor stops!
- Place a cube (1) having the height of A = 12.5 mm under
the presser foot.
- Screw in thoroughly downwards the screw (2).
- Tighten slightly the screw (3) in such a way that the lever (4)
turns on the shaft (5) with a certain friction moment.
- Push with the screwdriver on the lever (4), until it attains the
wall inside the arm of the sewing machine. In this position,
tighten duly the screw (3).
- Check the axial clearance of the shaft (5) which should be the
least possible.
- Set the normal pressure force of the presser foot.
4
5
3
2
1
A
6
3
1
4
2
5
3
5
4
6
1
2