28. Changing the flat-toothed belt
Removal:
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Remove the housing in accordance with the adjustment and repair instructions.
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Turn the handwheel until the lobe of feed eccentric 5 is positioned at the rear (fig. 66).
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Loosen fastening screw of tensioning roller.
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Tilt the machine to the rear.
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Unscrew and remove fastening screw 98 of clamping plate 99 on the lower right calotte bearing.
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Remove the clamping plate.
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Slip off flat-toothed belt 100 from the upper and lower belt wheels 101 and 102.
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Lift complete hook driving shaft 28 out of the lower right calotte bearing 103 as far as it will go.
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Pull the flat toothed belt between calotte 104 and calotte bearing 103.
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Disconnect tension spring 105 on needle bar frame 106 (fig. 67).
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Remove lockwasher 54 on the needle bar frame.
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Remove circlip 107 on zigzag stepping motor 51.
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Dismantle the complete connecting rod 108.
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Loosen screw 109 on needle bar crank 110.
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Unscrew and remove both clamping plate screws 111.
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Dismantle both clamping plates 112.
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Lift the arm shaft with the crank as far out as possible from calotte bearings 113 and 114.
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Hold the needle bar crank firmly.
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At the same time move arm shaft 115 to the right until both parts are disengaged.
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Dismantle the complete arm shaft.
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Remove the flat-toothed belt from the housing to the top.
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