DeWalt DW897 Guide D'utilisation page 6

DW 897-220 5/2/02 1:48 PM
up to 1/8" (3mm). To remove the punch, loosen the head set screw
about 4-5 turns (See Figure 2). Slide the shoe assembly from the
head. Unscrew the punch from the connecting rod bushing. Punch
may be resharpened carefully on a bench grinder with a fine grit
wheel. Be careful that the punch does not become shorter than the
minimum length of 2.44 inches (2-7/16 inches or 61mm). Punches
shorter than this will not engage the die sufficiently and must be
replaced. The ground face must be square to the punch axis. After
grinding, carefully stone the ground edges to remove burrs. Do not
round over corners.
Figure 2
HEAD
CAM
SHAFT
PUNCH
CONNECTING
SET
ROD BUSHING
SCREW
DIE
PUNCH
SHOE
GUIDE
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Figure 3
CAM
HEAD
SHAFT
PUNCH
PUNCH
GUIDE
SHOE
DIE
WEAR
PLATE
Reassembly of Nibbler Head
Screw the punch fully into the connecting rod bushing. Slide the shoe
assembly over the end of the punch and into the head. NOTE:
Lubrication groove in punch face must not be exposed at front of
shoe. Turn the shoe to desired cut orientation. Tighten set screw.
Next, check punch engagement.
Checking Punch Engagement
Since the punch length is now changed, the punch engagement may
have to be adjusted. Check punch engagement by placing a flat
blade screwdriver in the cam shaft slot and turning the shaft. (See
Figure 2) Punch should dip .020" to .04" (.5 to 1.0mm) into the die at
the full down stroke position. Too much punch dip into the die will
result in a loss of capacity (bottom of punch will not clear die enough
on up stroke.)
Punch Engagement Adjustment
If the punch engagement should need adjustment, loosen the set
screw and rotate shoe either clockwise (punch deeper into die) or
counterclockwise (punch out of die). Tighten set screw firmly. Turn
cam shaft with screwdriver in slot to check punch engagement
(moving punch fully down). Repeat as necessary.
Die Replacement
If the die becomes dull, replace it. Replace old die by removing two
screws at the front (Figure 2). Install new die and tighten screws.
Recheck punch engagement and adjust punch depth if necessary.
Wear Plate
This tool is equipped with a wear plate to increase the life of the
shoe (See Figure 3). The wear plate fits between the shoe and the
punch. Anytime the punch, punch guide or die is removed, inspect
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