Synchronisation Of Underfeed And Roller Overfeed - Duerkopp Adler 271 Service Manual

2.7.1 Synchronisation of underfeed and roller overfeed

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Caution: danger of injury
Turn off the main switch.
Synchronisation may only be adjusted with the sewing machine
switched off.
Regulation and inspection
The operation of the underfeed and roller overfeed should be
synchronised.
On no account may the movement of the overfeed roller be completed
before that of the feed dog.
This ensures that the material between the sewing foot and the roller
remains under tension, thus minimising seam-crimping when the
stitches are tightened.
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Remove bobbin-winder cover.
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Lock the sewing machine:
class 273: in position B
class 274: in position E.
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The groove 4 of the cam 2 and the groove 3 of the connecting rod
1 must coincide.
Adjustment
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Remove locking pin.
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Undo fastening screws of cam 2.
It should be possible to rotate the cam on the shaft with minimum
effort.
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Secure cam 2 with a screwdriver.
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Turn handwheel:
class 273: to position B
class 274: to position E.
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Retighten fastening screws of the cam 2.
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Check that groove 4 of the cam and groove 3 of the connecting rod
coincide.
If not, the adjustment must be repeated.
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Replace bobbin-winder cover.
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