Merrow Class 70 - Class 70 Cutter Adjustment; Class 70 Cutter Positioning; Merrow Class 70 Cutter Sharpening; Class 70 Cutter Sharpening Procedure

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
CLASS 70 INSTRUCTION BOOK
UPPER AND LOWER CUTTER
46. GENERAL: The upper and lower cutter may be adjusted up and down and laterally to the
right or left.
47. The position of cutters determines the width of the fabric within the seam . When a butt
seam is desired, the cutting surfaces should be positioned approximately in the middle of the
Needle Flate Chaining Finger. When a gap seam is desired, the cutting surfaces shouldbe
positioned as for a butt then moved to the left about 1/2 the width of the gap required. Lap
seams are created by setting the cutting surfaces to the right of the butt seam posit ion. The
position of the cutters will vary with the thickness of fabric and some trial settings should be
made
to determine the correct position for each weight of material. Loosely woven materials
require a wider setting than light fabrics.
48. The L. C. Holder slides in the L. C. Holder Support Assembly providing lateral movement
to the Lower Cutter . Do not allow the Lower Cutter to push too tightly against the Upper
Cutter. If more than a light pressure is required, it usually indicates that the cutters are dull
and
should be sharpened.
ADJUSTMENT
49. Set the cutting edge of the Lower Cutter slightly above the upper surface of the Needle
Plate by means of the L. C. C. Nut 2-5 / 32. Do not set this cutter high enough to contact the
lower surface of the Presser Foot.
50. Clamp the L. C. Holder to the width of trimming desired by Screw 86-3/16. Turn the
machine over by hand and set the Upper Cutter so that in its lowest position its cutting edge is
a little below the top edge of the Lower Cutter. This adjustment is made by U. C. Clamp
Screw and U.C. Holder Screw.
51. Loosen L. C. H. C. Screw 86-3 / 16 and turn the Machine over by hand. The downward pro-
jection at the rear of the Upper Cutter should be in contact with the lower Cutter at all times.
52. Press the L, C. Holder lightly to hold the cutters together and tighten the L. C.H. C.
Screw 86-3/16 .
SHARPENING THE CUTTER S
53. The Upper and Lower Cutters must be sharpened in a Cutter Grinder, which has a Jig to hold
the cutters at the proper angle. Those customers who do not have a Merrow Cutter Grinder can have
dull cutters sharpened by sending them to your distributor or to the Merrow Machine Company,
Newington, Connecticut 06111.
54. When using
the Merrow Cutter Grinder, be sure that the retaining groove for the cutter is
perfectly clean before inserting the cutter and clamping the cutter into the cutter holder. The
cutter should be carried entirely across the grinding face of the wheel, to prevent the wheel
from becoming worn unevenly and requiring replacement so that cutters may be sharpened
properly.
55. Very little need be ground off the cutters . If too much is ground at one passage across the
face of the wheel, the temper of the cutter will be drawn and its cutting quality greatly im-
paired.
56. The cutter should not be discolored by grinding.
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