−
13
−
3-6 Adjusting the position of moving knife movement
1) Proper movement of the moving knife
The position of moving knife when it moves until it will go no further is the position where the front top end of
moving knife is receded 2.5 to 3 mm from the center of the needle. When the amount of recession is excessively
small, the moving knife cannot scoop needle thread or bobbin thread when trimming thread, and if the amount
is excessively large, feed dog may come in contact with moving knife. Therefore, properly adjust the moving
knife position.
Reference for positioning the moving knife at the predetermined position is the position where the V groove
indicated on the knife installing base is aligned with the periphery of moving knife.
2) Adjusting the moving knife position
Adjustment is performed by changing the right and left positions of moving knife link pin (Fig. 15 (1)) when the
sewing machine stops.
①
Loosen the lock nut of moving knife link pin (Fig. 15 (1)).
②
Following the predetermined position in Fig. 14, move the moving knife link pin to the left and right so that
V groove (Fig. 14) for positioning moving knife on the knife installing base is aligned with the periphery of
moving knife.
③
Tighten the lock nut of moving knife link pin at the proper position.
Set the position of moving knife pin to the right to increase the amount of recession, and to the left to
decrease the amount.
3) When adjustment cannot be performed by moving knife link pin only
①
Loosen the lock nut of moving knife link pin (Fig. 15 (1)).
Fig. 14
2.5 to 3 mm
Moving knife
Center of needle
When moving knife recedes most.
0.5 mm
(0.2 to 0.7)
V groove for positioning
moving knife
Predetermined position
