Singer 601 - Advanced Features and Machine Care; Using the Push Button Back Tack; Using the Wiper Feature; Machine Care and Maintenance

3. Use sensor retainer supplied with the machine and be sure it is correctly secured in position.
NOTE: The sensor plate for upper needle position should not be reset in order to solve the problem of tension
releasing mechanism not being released when needle stops in the upper needle position.
This adjustment should be made hv resetting the sensor unit on the hub of machine pulley as instructed below.
a. Loosen the two set screws holding the sensor unit and while holding the sensor with one hand, turn machine
pulley slightly over toward the front of machine.
b. Hold sensor in this position and temporarily tighten the first screw.
c. Run machine and check whether the tension releasing mechanism is released when the needle stops in the
upper position. Repeat above, il necessary.
d. Firmly tighten both first and second set screws.
TIMING - ACTUATION OF TRIMMER SOLENOID
The trimmer solenoid is actuated when the take-up lever reaches a point 10mm (.394"') before its lower dead
point. The timing of this actuation is controlled by the sensor plate (B) in the sensor unit. (Refer to item 3 under
Description of Trimming Operation).
TIMING - COMPLETION OF ACTUATION OF TRIMMER SOLENOID
The current supply to the trimmer solenoid is cut off completing its actuation when the tension release action
plate pin B is in the range C shown in Fig. 68. This timing is controlled by the sensor plate (g) and when adjustment
is necessary, reset this sensor plate.
Turn machine pulley until the clearance between tension release action plate pin and tension release action cam
C is approximately lmrn (0.39'') (Fig. 68) and while holding the machine pulley in this position, set sensor plate ©
as shown in Fig. 69.
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Fig. 68
Fig. 69