DUST
CONTROL
Place the saw flat on the floor
near the wall to be undercut.
Make certain blade is set
parallel to the floor.
Make sure the blade holding
screw, and height locking
wing screws are tightened
securely. Handle ratchet
teeth should interlock and
three-arm knobs be tight-
ened securely (figure 10).
Always keep the handle in
the vertical position for gen-
eral undercutting.
Lower the handle for under-
cutting toe spaces (figure 11). Be sure to lock knobs.
Plug in the saw and grasp handles firmly with both hands.
Keep one hand on the switch handle and one hand on the
ratchet handle at all times. Depress the safety lock button,
then pull the power switch.
To start a cut, use the wall to push the blade guard back
and expose blade.
DO NOT USE YOUR HAND!
First, plunge slowly to appropriate depth. Second, push
the saw forward. Move the saw from left to right only.
Don't force the saw; let blade cut at highest RPM pos-
sible. Do not pull the saw towards you or run in reverse.
Do not lift or angle the saw or kickback may result.
Remove the saw from the cut, and release the switch to stop.
Turn off and unplug saw.
Retract the height adjuster
so it is flush with the hous-
ing to allow clearance for
the Allen® wrench.
Push the spindle lock
button with one hand and
insert the Allen® wrench
into the blade screw with
other hand; then turn the
Allen® wrench until the
spindle engages with the
lock button (blade will
stop rotating).
Hold onto the plastic housing, then push hard on the Al-
len® wrench counter-clockwise to open. If the blade is
hard to remove, use a Vise Grip® to hold the blade.
Figure 3
SAFETY FIRST
HANDLES:
In use, keep both hands on the handles at all times.
KICKBACK HAZARDS:
While cutting, do not force the
saw. Also, keep the housing flat on the floor and the blade
parallel to the floor at all times. Angling may cause powerful,
dangerous kickback. Keep the saw RPMs high. Using a
dull blade will place a heavy load on your saw and increase the
danger of kickback. Use only Crain replacement blades.
EYE & EAR PROTECTION:
Always wear safety glasses when
using a power tool. Wear ear plugs when using this saw.
BLADE GUARD:
The blade guard attached to your saw is
for your safety and protection. If it becomes damaged, do
not operate your saw until it has been repaired. Keep the
blade guard in operating condition when using the saw.
DOUBLE-INSULATED:
This tool is constructed with two
separate layers of electrical insulation. A tool built with this
insulation system does not need to be grounded.
DANGEROUS ENVIRONMENTS:
Keep work area clean;
clutter invites accidents. Do not use the saw on damp or
wet floors. Be sure that there is good lighting. This saw
may throw sparks. Make certain that flammable materials,
especially explosive vapors, are not present. Use face or
dust mask if cutting operation is dusty.
ACCIDENTAL STARTING:
To avoid accidental starting, do
not carry tool while plugged in or with fingers on switch.
CORD ABUSE:
Never carry tools by the cord or yank the
cord to disconnect from an outlet. Keep cords away from
heat, oil, and sharp edges.
EXTENSION CORD:
To minimize power loss and prevent
overheating, use maximum of 25 feet long and 16 AWG.
HAIR & CLOTHING:
Keep all loose hair and clothing away
from the spinning blade at all times.
The Heavy-Duty Undercut Saw is designed for undercut-
ting affixed wooden door jambs, moldings, base, as well
as masonry and stone, to allow new floor coverings to be
fit underneath. Do not use this saw for sanding floors,
cutting metal, or any other purpose not described in this
instruction manual.
WORKING TERMINOLOGY:
Figure 1
BLADE INSTALLATION:
see Figure 3
BLADE HEIGHT ADJUSTMENT:
see Figure 4
A depth gauge adjustment scale is engraved on the
depth gauge with twelve
1
/
8
" increments (figure 6).
We recommend the depth of
cut be set to no more than
1
/
2
"
to minimize the chance of hit-
ting wall studs, nails, etc.
When undercutting wood
base, set depth to cut wood
only. Cutting sheetrock
makes dust that can dam-
age the saw over time.
To adjust the depth gauge,
loosen the depth gauge
three-arm knob and slide the
depth gauge in or out.
The depth adjuster accurately
controls the depth of cut at
any of three angles: straight-
on (figure 7), 45˚ left (figure 8),
or 45˚ right (figure 9).
Cutting at a 45˚ angle is easiest
to push the saw (figure 8).
For dust control, cutting at the
45˚ right angle is preferred.
This angle captures as much
dust as possible inside the
housing. When using this
saw with a vacuum, this is
DEPTH ADJUSTMENT:
Unplug the saw. Loosen the two height locking wing
nuts one to two turns.
Turn the two height adjustment three-arm knobs clock-
wise to increase blade height and counter clockwise to
decrease height.
It is best to turn both
height adjustment three-
arm knobs at the same
time to ensure the blade
is set parallel with the
floor.
Both the front of the
height adjuster and the
inside of the height ad-
Figure 9
Figure 11
Figure 8
Figure 10
Figure 7
CAUTION!
BLADE EXPOSED
WHILE CUTTING
KEEP HANDS
AWAY!
SWITCH
RATCHET
HANDLE
MOTOR
HOUSING
DEPTH GAUGE
ADJUSTMENT
SCALE
HEIGHT LOCKING
WING SCREW
DEPTH GAUGE
THREE-ARM KNOB
BLADE
GUARD
DEPTH
GAUGE
SPINDLE
LOCK
BUTTON
Figure 12
Figure 13
Figure 14
Cut towards the corner at 45˚ angle (see figure 12) until
the depth gauge meets the right wall (see figure 13).
Stop and unplug saw. Fully retract depth gauge and
continue the cut.
Push saw into the corner as shown (see figure 14).
WARNING: Depth gauge covers the blade and makes the
saw safer to use. Always unplug the saw and reset the
depth gauge when inside corner cutting is complete.
INSIDE CORNER CUTTING:
Figure 2
BLADE REMOVAL:
see Figure 2
BEST FOR
PUSHING
DUST
CONTROL
HEIGHT
ADJUSTMENT
THREE-ARM
KNOB
REFERENCE
LINES
USING THE SAW:
Figure 6
DEPTH GAUGE
THREE-ARM
KNOB
0"
1
/
2
"
1
/
4
"
EACH
LINE IS
1
/
8
"
DEEP
45º LEFT
ANGLE
SWITCH HANDLE
STRAIGHT
ON
45º
RIGHT
ANGLE
ALLEN®
WRENCH
Unplug the saw.
Place the blade spac-
er over the spindle.
Place the blade on top
of the blade spacer.
Place the blade clamp
through the arbor hole
of the blade with the
bottom slot of the
blade clamp prop-
erly aligned with the
spindle.
Insert and re-tighten
the blade screw. Push
in the spindle lock to
tighten. Be sure to
tighten firmly before use.
BLADE
SPACER
ALLEN®
WRENCH
BLADE
SCREW
BLADE
CLAMP
#821,
#805, or
#822
MUST
ENGAGE
SPINDLE
SPINDLE
UNPLUG THE SAW. REMOVE ALLEN®
WRENCH BEFORE STARTING.
UNPLUG THE SAW. REMOVE ALLEN®
WRENCH BEFORE STARTING.
VISE
GRIP®
BLADE
SCREW
Figure 4
juster have 10 reference lines, in
3
/
32
" increments (.093", one
blade thickness - figure 5). Max. height is 1".
To prevent saw kickback, the blade must be set parallel to the
floor. This can be ensured by checking from the front of the
saw that, on BOTH sides of the blade housing, the number
of lines below the bottom
edge of the blade hous-
ing are the same (figure 4),
OR by turning the saw
over and making sure the
bottom edge of the blade
housing is completely
parallel with a reference
line (figure 5).
It may be easiest to set
the saw blade flat on
top of the new flooring
to be fit beneath the desired undercut, and turn the height
adjuster three-arm knobs clockwise until the height ad-
juster rests flat on the floor. From that point, for a snug fit
with the new floor, adjust height down by one reference
line (one blade thickness).
Securely tighten the height locking wing screws before use.
HEIGHT ADJUST-
ER THREE-ARM
KNOBS
HEIGHT
LOCKING
WING SCREW
BOTTOM
EDGE OF
HOUSING
REFERENCE
LINES
NEW FLOOR TO
BE INSTALLED
HANDLE REMOVED FOR CLARITY -
DON’T USE WITHOUT HANDLE!
REFERENCE
LINES
REFERENCE
LINES
WING
SCREW
HEIGHT ADJUSTER
BOTTOM EDGE
OF HOUSING
BOTTOM
EDGE OF
HOUSING
RATCHET
TEETH
THREE-ARM
KNOB
the most effective angle to
control dust (figure 9).
Re-tighten the three-arm
knob firmly before use.
Figure 5
TOE
SPACE
