DURKOPP ADLER 878-M PREMIUM, Service Instructions Manual

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Thread trim
56 Service Instructions 878-M PREMIUM - 03.0 - 10/2019
14.4 Setting the cutoff curve
Obr. 46: Setting the cutoff curve
Proper setting
1. If the lever (13) is in its basic rest position, there is a distance A = 0.05
to 0.1 mm between the cutoff curve (9) top point and the roller (10). In
this position, the moving knife is at the longest rear distance from the
sewing machine operator.
2. The angular position (timing) of the cutoff curve (9) should be such that
thread trimming appears when the angle on the handwheel is 40° to 45°
(60° for short thread trimming). This is guaranteed when the roller (10)
fits in the curve path recess (11) at the handwheel position 90° (100° for
short thread trimming).
1. Tilt the machine head (

p. 15 ).
2. Open the hook cover.
3. Loosen the screws on the ring (14).
4. Loosen the screws on the cutoff curve (9).
5. Turn the top of the cutoff curve (9) to face the roller (10). Move the
cutoff curve to the side so that the distance between the cutoff curve
and the roller is (A) = 0.05 to 0.1 mm.
6. Move the ring (14) to the right as far as it will go to the cutoff curve (9).
Take care that the looping stroke is not interfered with (

p. 35 ).
7. Tighten the screws on the ring (14).
8. Tighten the screws of the cutoff curve (9) so that the blade of the moving
knife (7) and the blade of the fixed knife (5) are aligned at 40° to 45°
on the handwheel.
9. Check the setting of the distance as prescribed in instruction 1, the
angle of the cutoff curve according to instruction 2 and that of the looping
stroke (

p. 35 ).
(9) - Cutoff curve
(10) - Rolle
(11) - Curve path recess
(12) - Clamp joint screw
(13) - Lever
(14) - Ring
(5) - Fixed knife
(7) - Moving knife
⑤
⑦
⑭ ⑬
⑫
⑨
⑪
⑩
A