DeWalt 7749 - Troubleshooting and Detailed Adjustments; Rollerhead Bearing and Arm Clamp Adjustment

ADJUSTING
ROLLERHEAD
BEARINGS
TO ARM
TRACKS
The rollerhead
is suspended
by
four
special tolerancc,
grcased-packed,
double
shield
ball bearings.
These
bearings are mounted
on two straight
bearing
shafts
and
two
eccentric
bearing shafts.
In
proper
adlustment thc top and
bottom radii
of
all
four
bearings
should
be
in
contact with the
arm tracks
for
their entire
length
and head
should roll freely
but with
some
resistance.
Excessive
bcaring
pressure
will
cause
diflicult operation
and
rapid
wear. Too
little
pressure
will cause
loss
of accuracy
and
the saw will
try to
feed
itsclf into
the material
bein-e crosscut.
Proper
adjustment
will require
a force
of 4 to 6 pounds
to move
the
rollerhead
along
the arm
at a
constant speed. The front
and rear
bearings
should bc adjusted
to
contribute
equally to this force.
l.IoTE:
the end cap was removed
for clarity and
it
need not
be removed for
this
adjustment.
(a)
Wipe
tracks
with
a clean
dry
lint-free
cloth.
(b)
Bring
motor,
yoke,
and rollerhead
assemblies
to
the end of arm.
(c)
Set in
"out
rip"
position.
(d)
Loosen hex
nuts on left
side, front
and rear.
(e)
Insert
Vs" Allen wrench
in recess
at
bottom of
shafts and turn
bearing
shaft
until the
bearing
is snugly
aqainst the
track.
Repeat
for
the second
bearing.
Check the force
required
to move
the rollelhead.
Rcadjust
as
required.
(f)
Tighten
the hex
lock
nuts while holding
each bcaring
shaft in its adjusted
position.
ARM TO
COLUMN
Prior
to readjusting
the
arm clamp
cam check
adjustment
of the arm
to column. With
the arm
clamp
released
there
should
be no
vertical plav
in the
arm.
and
the arm
should
fir snuelv
on
the
column.
To adjust:
(a)
Loosen
trvo
jam
nuls
(.{)
in
slLrr at rear
of arm.
turning
them clockrvise.
(b)
{diust
bolts
(B
)
for proper
fir
and re-
ti-shten
jam
nuts
(A).
REMOVING
SHROUD
To make
adjustments
in the
arm
it is
necessary
to
remove
the
arm
cover, as follorvs:
(a)
Remove
elevating handle.
Handle is
held
on
by a set
scre\\'.
(b)
Remove
front
end
cap
&
mirer
clamp
handle.
(c)
Remove
arm
cover
bv rotatins
it over
the handle
post.
ADJUSTING
ARM
CLAMP
The
arm
clamp
handle
operates
a
cam that clamps
the
miter
latch
from
the
0: and
45:
slots.
To
adjust:
(a)
Loosen
ser
screw
(A)
on
clamp
bolt
(B)
(b)
To
tighten
clamp turn
clamp
bolt
clockrvise,
be
made
prior
to trying
the
clamp.
)
(c)
Retighten
set screw
(A).
E--'
''.-
\
A
Cross section
of back
of arm
with
shroud removed
and releases
the arm. and lifts
in
clamp cam
pivot pin
(C).
(Very
little
adjustment
shouid