The Lowest Speed Of The Machine; The Homing Speed Of The Machine - Husqvarna 6690 Manual

Speed control
The stop-right function
The lowest speed of the motor
Requirements
The machine should manage a lowest speed of
+20
100 r/min.
-0
Action
Remove the wall plug. Set the thread take-up lever at the
lowest position and remove the handwheel. Remove the
belt guard. Set the stop-right pushbutton at the neutral
position. Connect the machine but remember that the
brush holder and open wires of the motor and the rear
of the printed circuit are live and unprotected, even if the
main switch is turned off. Insert the service cassette.
Turn on the main switch. Start the machine and let it run
a few revolutions until the step motor is well in operation.
Press the button under 110 (speed r/min). Depress the
foot control so that the machine runs at the lowest
possible speed or re-set the changeover switch if
foot control with changeover switch 411 6539 is
used. The illuminated light on the panel indicates the
speed of the machine.
Adjustment
The number of revolutions can be adjusted by means
of the lower potentiometer (P1). Turn the
potentiometer anti-clockwise for higher speed,
clockwise for lower speed.
Comment
There are magnetic bars on the upper part of the printed
circuit which sense the position of the hand wheel. These must not come into contact with
metal objects. For this reason always set the thread take-up lever at the lowest position when
removing or replacing the handwheel, so that the inside plate of the handwheel cannot come
into contact with the magnetic bars.
Homing speed of the machine
Explanation
The homing speed is a measurement of the capacity of the electronics to turn the arm shaft
after release of the foot control. It should be sufficient to drive the machine to the set stop-right
position.
Action
Set the stop-right push-button to the up or down position. Remove the handwheel.
Start the machine and depress the foot control so that the machine runs at the lowest possible
speed or re-set the changeover switch if foot control or reset the changeover switch if foot
control with changeover switch 411 6539 is used. The illuminated light on the panel indicates the
speed of the machine. Release the foot control or re-set the changeover switch. The speed
must not increase during the first second but a slight decrease is acceptable.
Adjustment
The homing speed is set by means of the upper potentiometer (P2). Higher speed is obtained
by turning the potentiometer anti-clockwise, lower by turning it clockwise.
Comments
If the speed is too high, the machine will make extra stitches.
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