Beisler 739-23-1 Service Manual - Manual (Page 35)

3.4.2 Adjustment of toothed belt tension
Caution! Risk of injury!
Switch off main switch!
Check and adjust tension of toothed belt only when the sewing
machine is switched off.
Instruction and inspection
When the material clamp guide is in its end position at the front, it
should be possible to slightly squeeze the toothed belt.
Consequences of excessive belt tension
–
Shorter service life
– Running noises
Consequences of insufficient belt tension
–
Nonconforming meshing between belt teeth and wheel
– Skipping of teeth under load
– Varying stitch lengths
Adjustment of setting
Left toothed belt
–
Loosen counternut 3.
– Adjust the belt wheel 2 by means of the nut at its rear.
Increase or reduce tension of the toothed belt 1.
– Tighten counternut 3.
Right toothed belt
–
Loosen screws 4 on the securing plate of the motor.
– Move step motor 5 to adjust tension of toothed belt.
– Tighten screws 4.
3-35
3 2 1
5 4