DeWalt DHS780 - Cutting Techniques; Cut Quality and Grooving; Workpiece Clamping and Support

16
ENGLISH
Quality of Cut
The smoothness of any cut depends on a number of variables, such as the material being cut,
blade type, blade sharpness and rate ofcut.
When smoothest cuts are desired for molding and other precision work, a sharp (60 tooth
carbide) blade and a slower, even cutting rate will produce the desiredresults.

WARNING: Ensure that the material does not move or creep while cutting; clamp it
securely in place. Always let the blade come to a full stop before raising arm. If small
fibers of wood still split out at the rear of the workpiece, stick a piece of masking tape on
the wood where the cut will be made. Saw through the tape and carefully remove tape
whenfinished.
Non-Through-Cutting (Grooving and Rabbeting) (Fig. A)
Your saw is equipped with a grooving stop
34
, depth adjustment screw
33
and wing nut
32
to allow for groovecutting. Instructions in the Crosscuts, Bevel Cuts and Cutting Compound
Miters sections are for cuts made through the full thickness of the material. The saw can also
perform non-through cuts to form grooves or rabbets in thematerial.
Grooving (Fig. A)
Refer to Grooving Stop for detailed instructions for setting depth of cut. A piece of scrap wood
should be used to verify the desired depth ofcut.
1. Hold the wood firmly on the table and against the fence
15
. Align the cut area
underneath the blade. Position the saw arm fully forward, with blade in down position.
Turn on the saw by pushing the lock-off button
5
to the left, and then depress the trigger
switch
4
shown in FigureA. Smoothly, push saw arm rearward to cut a groove through
the workpiece.
2. Release the trigger switch with the saw arm down. When saw blade has completely
stopped, raise the saw arm. Always let the blade come to a full stop before raising thearm.
3. To widen the groove, repeat steps 1–2 until the desired width isobtained.
Clamping the Workpiece

WARNING: A workpiece that is clamped, balanced and secure before a cut may become
unbalanced after a cut is completed. An unbalanced load may tip the saw or anything the
saw is attached to, such as a table or workbench. When making a cut that may become
unbalanced, properly support the workpiece and ensure the saw is firmly bolted to a
stable surface. Personal injury mayoccur.

WARNING: The clamp foot must remain clamped above the base of the saw whenever
the clamp is used. Always clamp the workpiece to the base of the saw – not to any other
part of the work area. Ensure the clamp foot is not clamped on the edge of the base of
thesaw.

CAUTION: Always use a work clamp to maintain control and reduce the risk of personal
injury and workpiecedamage.
Use the material clamp provided with your saw. The left or right fence will slide from side to
side to aid in clamping. Other aids such as spring clamps, bar clamps or C-clamps may be
appropriate for certain sizes and shapes ofmaterial.
To Install Clamp (Fig. A)
1. Insert it into the hole
28
behind the fence. The clamp should be facing toward the back of
the mitre saw. The groove on the clamp rod should be fully inserted into the base. Ensure
this groove is fully inserted into the base of the mitre saw. If the groove is visible, the clamp
will not besecure.
2. Rotate the clamp 180° toward the front of the mitresaw.
3. Loosen the knob to adjust the clamp up or down, then use the fine adjust knob to firmly
clamp theworkpiece.
NOTE: Place the clamp on the opposite side of the base when beveling. ALWAYS MAKE DRY
RUNS (UNPOWERED) BEFORE FINISH CUTS TO CHECK THE PATH OF THE BLADE. ENSURE THE
CLAMP DOES NOT INTERFERE WITH THE ACTION OF THE SAW ORGUARDS.
Support for Long Pieces
ALWAYS SUPPORT LONGPIECES.
For best results, use the DE7023-XJ or DE7033-XJ leg stands to extend the table width of your
saw. Support long workpieces using any convenient means such as sawhorses or similar
devices to keep the ends fromdropping.
Cutting Picture Frames, Shadow Boxes and Other Four-Sided
Projects (Fig.W)
Try a few simple projects using scrap wood until you develop a “feel” for your saw. Your saw is
the perfect tool for mitring corners like the one shown in FigureW.
Sketch 1 in FigureW shows a joint made with the bevel adjustment method. The joint shown
can be made using eithermethod.
• Using bevel adjustment:
- The bevel for the two boards is adjusted to 45° each, producing a 90°corner.
- The mitre arm is locked in the zero position and the bevel adjustment is locked at 45°.
- The wood is positioned with the broad flat side against the table and the narrow edge
against thefence.
• Using mitre adjustment:
- The same cut can be made by mitring right and left with the broad surface against
thefence.
Cutting Trim Molding and Other Frames (Fig.W)
Sketch 2 in FigureW shows a joint made by setting the mitre arm at 45° to mitre the two
boards to form a 90° corner. To make this type of joint, set the bevel adjustment to zero and
the mitre arm to 45°. Once again, position the wood with the broad flat side on the table and
the narrow edge against thefence.
The two sketches in FigureW are for four-sided objects only. As the number of sides changes,
so do the mitre and bevel angles. The chart below gives the proper angles for a variety of
shapes, assuming that all sides are of equallength.
Number of Sides Mitre or Bevel Angle
4 45°
5 36°
6 30°
7 25.7°
8 22.5°
9 20°
10 18°
For a shape that is not shown in the chart, use the following formula: 180° divided by the
number of sides equals the mitre (if the material is cut vertically) or bevel angle (if the material
is cut laying flat).
Cutting Compound Mitres (Fig.V,X)
A compound mitre is a cut made using a mitre angle and a bevel angle at the same time.
This is the type of cut used to make frames or boxes with slanting sides like the one shown in
FigureV.

WARNING: If the cutting angle varies from cut to cut, check that the bevel lock knob and
the mitre lock handle are securely locked. These must be locked after making any changes
in bevel ormitre.

WARNING: The saw must be fixed on a base support when performing compound cuts
to prevent tip over. Refer to Bench Mounting and Fig.GG.
The chart shown below will assist you in selecting the proper bevel and mitre settings for
common compound mitrecuts.
SET THIS BEVEL ANGLE ON SAW
SET THIS MITER ANGLE ON SAW
ANGLE OF SIDE OF BOX (ANGLE"A")
SQUARE BOX
6 SIDED BOX
8 SIDED BOX
• Select the desired angle A (Fig.X) of your project and locate that angle on the appropriate
arc in thechart.
• From that point follow the chart straight down to find the correct bevel angle and straight
across to find the correct mitreangle.
• Set your saw to the prescribed angles and make a few trial cuts. Practise fitting the cut
piecestogether.
Example: To make a 4-sided box with 26° exterior angles (Angle A, Fig.X), use the upper right
arc. Find 26° on the arc scale. Follow the horizontal intersecting line to either side to get mitre
angle setting on saw (42°). Likewise, follow the vertical intersecting line to the top or bottom
to get the bevel angle setting on the saw (18°). Always try cuts on a few scrap pieces of wood
to verify the settings on thesaw.
Cutting Base Moulding (Fig.N, Y)
ALWAYS MAKE A DRY RUN WITHOUT POWER BEFORE MAKING ANYCUTS.
To complete straight 90° cuts, position the wood against the fence and hold it in place as
shown in FigureY. Turn on the saw, allow the blade to reach full speed and lower the arm
smoothly through thecut.
Cutting Base Molding from 76 mm to 171 mm High Vertically Against
theFence
NOTE: Use the slide lock lever
19
, shown in FigureN, when cutting base molding measuring
from 76 mm to 171 mm high vertically against thefence.
Position material as shown in FigureY.