Advertisement
This instruction manual uses the following safety alert symbols and words to alert you to hazardous situations and your risk of personal injury or property damage.
Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
(Used without word) Indicates a safety related message.
NOTICE: Indicates a practice not related to personal injury which, if not avoided, may result in property damage.
Read all safety warnings, instructions, illustrations and specifications provided with this power tool. Failure to follow all instructions listed below may result in electric shock, fire and/or serious injury.
The term "power tool" in the warnings refers to your mains-operated (corded) power tool or battery operated (cordless) power tool.
Do not allow familiarity (gained from frequent use of your saw) to replace safety rules. Always remember that a careless fraction of a second is sufficient to inflict severe injury.
Never modify the power tool or any part of it. Damage or personal injury could result.
Cutting plastics, sap coated wood, and other materials may cause melted material to accumulate on the blade tips and the body of the saw blade, increasing the risk of blade overheating and binding while cutting.
ALWAYS use safety glasses. Everyday eyeglasses are NOT safety glasses. Also use face or dust mask if cutting operation is dusty. ALWAYS WEAR CERTIFIED SAFETY EQUIPMENT:
Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm. Some examples of these chemicals are:
Your risk from these exposures varies, depending on how often you do this type of work. To reduce your exposure to these chemicals: work in a well ventilated area, and work with approved safety equipment, such as those dust masks that are specially designed to filter out microscopic particles.
Volts | Total length of Cord in Feet (meters) | ||||
120 V | 25 (7.6) | 50 (15.2) | 100 (30.5) | 150 (45.7) | |
240 V | 50 (15.2) | 100 (30.5) | 200 (61.0) | 300 (91.4) | |
Ampere Rating | American Wire Gauge | ||||
More Than | Not More Than | ||||
0 | 6 | 18 | 16 | 16 | 14 |
6 | 10 | 18 | 16 | 14 | 12 |
10 | 12 | 16 | 16 | 14 | 12 |
12 | 16 | 14 | 12 | Not Recommended |
The label on your tool may include the following symbols. The symbols and their definitions are as follows:
V | volts | |
Hz | hertz | |
min | minutes | |
⎓ or DC | direct current | |
![]() | Class I Construction (grounded) | |
.../min | per minute | |
BPM | beats per minute | |
IPM | impacts per minute | |
RPM | revolutions per minute | |
sfpm | surface feet per minute | |
SPM | strokes per minute | |
A | amperes | |
W | watts | |
![]() | alternating current | |
![]() | alternating or direct current | |
![]() | Class II Construction (double insulated) | |
no | no load speed | |
n | rated speed | |
![]() | earthing terminal | |
safety alert symbol | ||
![]() | visible radiation | |
![]() | wear respiratory protection | |
![]() | wear eye protection | |
![]() | wear hearing protection | |
![]() | read all documentation |
For your convenience and safety, the following warning labels are on your miter saw.
ON MOTOR ENDCAP:
TO REDUCE THE RISK OF INJURY, USER MUST READ INSTRUCTION MANUAL. WEAR EYE PROTECTION AND RESPIRATORY PROTECTION. USE ONLY IDENTICAL REPLACEMENT PARTS. DO NOT EXPOSE TO RAIN OR USE IN DAMP LOCATIONS.
ON FENCE:
ALWAYS ADJUST FENCE PROPERLY BEFORE USE. CLAMP SMALL PIECES BEFORE CUTTING. SEE MANUAL.
ON GUARD:
DANGER – KEEP AWAY FROM BLADE.
ON UPPER GUARD:
PROPERLY SECURE BRACKET WITH BOTH SCREWS BEFORE USE.
ON TABLE: (2 PLACES)
KEEP HANDS AND BODY OUT OF THE PATH OF THE SAW BLADE. CONTACT WITH BLADE WILL RESULT IN SERIOUS INJURY. DO NOT OPERATE SAW WITHOUT GUARDS IN PLACE. CHECK GUARDING SYSTEM TO MAKE SURE IT IS FUNCTIONING CORRECTLY. DO NOT PERFORM ANY OPERATION FREEHAND. NEVER REACH IN BACK OF SAW BLADE TURN OFF TOOL AND WAIT FOR SAW BLADE TO STOP BEFORE MOVING WORKPIECE OR CHANGING SETTINGS OR MOVING HANDS. NEVER CROSS ARMS IN FRONT OF BLADE. ALWAYS TIGHTEN ADJUSTMENT KNOBS BEFORE EACH USE. DISCONNECT POWER BEFORE CHANGING BLADE OR SERVICING.
ON TABLE: (2 PLACES)
Double insulated tools are constructed throughout with two separate layers of electrical insulation or one single layer of reinforced insulation between you and the tool's electrical system. Tools built with this insulation system are not intended to be grounded. As a result, your tool is equipped with a two prong plug which permits you to use extension cords without concern for maintaining a ground connection.
NOTE: Double insulation does not take the place of normal safety precautions when operating this tool. The secondary insulation system is for protection against injury resulting from a possible failure of the primary insulation within the tool.
WHEN SERVICING USE ONLY IDENTICAL REPLACEMENT PARTS. Repair or replace damaged cords.
Polarized plugs (one blade is wider than the other) are used on equipment to reduce the risk of electric shock. When provided, this plug will fit in the polarized outlet only one way. If the plug does not fit fully in the outlet, reverse the plug. If it still does not fit, contact a qualified electrician to install the proper outlet. Do not change the plug in any way.
Be sure your power supply agrees with the nameplate marking. 120 volts, AC means that your saw will operate on alternating current only. A voltage decrease of 10 percent or more will cause a loss of power and overheating. All DeWALT tools are factory tested. If this tool does not operate, check the power supply.
Capacity of cut
50° miter left and 60° miter right 49º bevel left and right 0° miter | |
Max. Height 4.4" (112 mm) Max. Width 13.75" (349 mm) | Resulting Width 9.1" (231 mm) Resulting Height 3.0" (76 mm) |
45° miter | |
Max. Height 4.4" (112 mm) Max. Width 9.6" (244 mm) | Resulting Width 5.8" (147 mm) Resulting Height 3.0" (76 mm) |
45° bevel - Left | |
Max. Height 3.1" (79 mm) Max. Width 13.75" (349 mm) | Resulting Width 11.4" (290 mm) Resulting Height 1.7" (43 mm) |
45º bevel - Right | |
Max. Height 2.2" (56 mm) Max. Width 13.75" (349 mm) | Resulting Width 11.4" (290 mm) Resulting Height 1.1" (28 mm) |
Your saw is capable of cutting baseboard moldings 0.75" (19 mm) thick by 6.5" (165 mm) tall on a 45° right or left miter.
Drive
120 Volt motor
15 Amp motor
3800 RPM
Cut helical gears
Multi-V belt
Carbide tooth blade
Automatic electric brake
Check the contents of your miter saw carton to make sure that you have received all parts. In addition to this instruction manual, the carton should contain:
1 DWS779 miter saw
1 DeWALT 12" (305 mm) diameter saw blade
In bag:
1 Blade wrench
1 Material clamp
2 Lock washers
2 Wing nuts
1 Dust bag
1 Base extension (right)
1 Base extension (left)
1 Instruction manual
This heavy duty miter saw is designed for professional wood cutting applications.
DO NOT use under wet conditions or in presence of flammable liquids or gases.
This miter saw is a professional power tool. DO NOT let children come into contact with the tool. Supervision is required when inexperienced operators use this tool.
Your miter saw is not fully assembled in the carton. Refer to the Assembly and Adjustments section for assembly instructions. Open the box and lift the saw out by the convenient the lifting handle 13, as shown in Figure B.
Place the saw on a smooth, flat surface such as a workbench or strong table.
Examine Figure A to become familiar with the saw and its various parts. The section on adjustments will refer to these terms and you must know what and where the parts are.
Pinch Hazard. To reduce the risk of injury, keep thumb underneath the handle when pulling the handle down. The lower guard will move up as the handle is pulled down which could cause pinching. The handle is placed close to the guard for special cuts.
Press down lightly on the operating handle 2 and pull lock down pin 17. Gently release the downward pressure and hold the arm allowing it to rise to its full height. Use the lock down pin when carrying the saw from one place to another. Always use the lifting handle 13 to transport the saw or the hand indentations 9 shown in Figure A.
(Fig. A)
Mounting holes 3 are provided in all 4 feet to facilitate bench mounting, as shown in Figure A. (Two different-sized holes are provided to accommodate different sizes of screws. Use either hole, it is not necessary to use both.) Always mount your saw firmly to a stable surface to prevent movement. To enhance the tool's portability, it can be mounted to a piece of 1/2" (12.7 mm) or thicker plywood which can then be clamped to your work support or moved to other job sites and reclamped.
NOTE: If you elect to mount your saw to a piece of plywood, make sure that the mounting screws don't protrude from the bottom of the wood. The plywood must sit flush on the work support. When clamping the saw to any work surface, clamp only on the clamping bosses where the mounting screw holes are located. Clamping at any other point will surely interfere with the proper operation of the saw.
To prevent binding and inaccuracy, be sure the mounting surface is not warped or otherwise uneven. If the saw rocks on the surface place a thin piece of material under one saw foot until the saw sits firmly on the mounting surface.
(Fig. A)
To reduce the risk of serious personal injury, turn off the tool and disconnect it from the power source before attempting to move it, change accessories or make any adjustments.
To reduce the risk of serious personal injury, always lock the rail lock knob 29, miter lock handle 5, bevel lock knob 11, lock down pin 17 and fence adjustment knobs 14 before transporting saw.
In order to conveniently carry the miter saw from place to place, a lifting handle 13 has been included on the top of the saw arm and hand indentations 9 in the base, as shown in Figure A. To transport the saw, lower the arm of the saw and press in the lock down pin 17 to secure the arm.
To reduce the risk of serious personal injury, turn unit off and disconnect it from power source before making any adjustments or removing/installing attachments or accessories. An accidental start-up can cause injury.
NOTE: Your miter saw is fully and accurately adjusted at the factory at the time of manufacture. If readjustment due to shipping and handling or any other reason is required, follow the steps below to adjust your saw.
Once made, these adjustments should remain accurate. Take a little time now to follow these directions carefully to maintain the accuracy of which your saw is capable.
Base extensions must be assembled to both sides of the saw's base before using the saw.
(Fig. A, D–F)
To reduce the risk of serious personal injury, turn off the tool and disconnect it from the power source before attempting to move it, change accessories or make any adjustments.
(Fig. A, G)
Unlock the miter lock handle 5 and swing the miter arm until the miter latch button 6 locks it at the 0° miter position. Do not lock the miter lock handle. Place a square against the saw's fence and blade, as shown. (Do not touch the tips of the blade teeth with the square. To do so will cause an inaccurate measure ment.) If the saw blade is not exactly perpendicular to the fence 10, loosen the four miter scale screws 8 that hold the miter scale and move the miter lock handle and the scale left or right until the blade is perpendicular to the fence, as measured with the square. Retighten the four screws. Pay no attention to the reading of the miter pointer at this time.
(Fig. A)
Unlock the miter lock handle 5 to move the miter arm to the zero position. With the miter lock handle unlocked, allow the miter latch to snap into place as you rotate the miter arm to zero. Observe the miter pointer 30 and miter scale 7 shown in Figure A. If the pointer does not indicate exactly zero, loosen the miter pointer screw 26 holding the pointer in place, reposition the pointer and tighten the screw.
(Fig. A, H, I)
To align the blade square to the table 16, lock the arm in the down position with the lock down pin 17. Place a square against the blade, ensuring the square is not on top of a tooth. Loosen the bevel lock knob 11 and ensure the arm is firmly against the 0° bevel stop. Rotate the 0° bevel adjustment screw 42 with the 1/2" blade wrench as necessary so that the blade is at 0° bevel to the table.
(Fig. I)
If the bevel pointer 43 does not indicate zero, loosen the screw 44 that holds it in place and move the pointer as necessary. Ensure the 0° bevel is correct and the bevel pointers are set before adjusting any other bevel angle screws.
(Fig. A, I)
To adjust the right 45° bevel angle, loosen the bevel lock knob 11 and pull the 0° bevel stop to override the 0° bevel stop. When the saw is fully to the right, if the bevel pointer does not indicate exactly 45°, turn the left 45° bevel adjustment screw 33 (Fig. A) with the 1/2" blade wrench until the bevel pointer 43 indicates 45°.
To adjust the left 45° bevel stop, first loosen the bevel lock knob and tilt the head to the left. If the bevel pointer does not indicate exactly 45°, turn the right 45° bevel adjustment screw until the bevel pointer reads 45°.
(Fig. A)
In order that the saw can bevel to many bevel positions, one of the fences may have to be adjusted to provide clearance. To adjust each fence, loosen the fence adjustment knob 14 and slide the fence outward. Make a dry run with the saw turned off and check for clearance. Adjust the fence to be as close to the blade as practical to provide maxi mum workpiece support, without interfering with arm up and down movement. Tighten the fence adjustment knob securely. When the bevel operations are complete, don't forget to relocate the fence.
For certain cuts, it may be desirable to bring the fences closer to the blade. To use this feature, back the fence adjustment knobs out two turns and move the fences closer to the blade past the normal limit, then tighten the fence adjustment knobs to keep the fences in this location. When using this feature, make a dry cut first to ensure the blade does not contact the fences.
NOTE: The tracks of the fences can become clogged with sawdust. If you notice that they are becoming clogged, use a brush or some low pressure air to clear the guide grooves.
(Fig. A, Y)
Pinch Hazard. To reduce the risk of injury, keep thumb underneath the handle when pulling the handle down. The lower guard will move up as the handle is pulled down which could cause pinching.
The lower guard 4 on your saw has been designed to automatically uncover the blade when the arm is brought down and to cover the blade when the arm is raised.
The guard can be raised by hand when installing or removing saw blades or for inspection of the saw. NEVER RAISE THE LOWER GUARD MANUALLY UN LESS THE BLADE IS STOPPED.
NOTE: Certain special cuts of large material will require that you manually raise the guard. Refer to Cutting large Material under Special Cuts.
The front section of the guard is louvered for visibility while cutting. Although the louvers dramatically reduce flying debris, they are openings in the guard and safety glasses should be worn at all times when viewing through the louvers.
(Fig. A)
Periodically check the rails 23 for any play or clearance. The right rail can be adjusted with the rail set screw 31 shown in Figure A. To reduce clearance, use a 4 mm hex wrench and rotate the rail set screw clockwise gradually while sliding the saw head back and forth. Reduce play while maintaining minimum slide force.
(Fig. A, J)
The miter lock rod 45 should be adjusted if the table of the saw can be moved when the miter lock handle 5 is locked (down). To adjust the miter lock, put the miter lock handle in the unlocked (up) position. Using a 1/2" open end wrench, loosen the lock nut 46 on the miter lock rod. Using a slotted screwdriver, tighten the miter lock rod by turning it clockwise. Turn the lock rod until it is snug, then turn counterclockwise one turn. To ensure the miter lock is functioning properly, re-lock the miter lock to a non-detented measurement on the miter scale – for example, 34º – and make sure the table will not rotate. Tighten lock nut.
Your compound miter saw has several main controls, which will be discussed briefly here. For more information on these controls, see the respective sections later in the manual.
Miter Control (Fig. A)
The miter lock handle 5 and miter latch button 6 allow you to miter your saw to 60° right and 50° left. To miter the saw, lift the miter lock handle, push the miter latch button and set the miter angle desired on the miter scale 7. Push down on the miter lock handle to lock the miter angle.
Trigger Switch (Fig. A)
The trigger switch 1 turns your saw on and off. A hole is provided in the trigger for insertion of a padlock to secure the saw.
Miter Latch Override (Fig. A)
The miter latch override 22 allows your saw to override the common stop angles. To override the common stop angles, push the miter latch button 6 and flip the miter latch override lever to the vertical position.
Bevel Lock Knob (Fig. A)
The bevel lock knob 11 allows you to bevel the saw 49° left or right. To adjust the bevel setting, turn the knob counterclockwise. The saw head bevels easily to the left or to the right once the 0° bevel override knob is pulled. To tighten, turn the bevel lock knob clockwise.
0° Bevel Override (Fig. A)
The bevel stop override allows you to bevel the saw to the right past the 0° mark.
When engaged, the saw will automatically stop at 0° when brought up from the left. To temporarily move past 0° to the right, pull the bevel lock knob 11. Once the knob is released, the override will be reengaged. The bevel lock knob can be locked out by twisting the knob 180°. When at 0°, the override locks in place. To operate the override, bevel the saw slightly to the left.
45° Bevel Stop Override (Fig. A)
The bevel stop overrides are held secure with their attachment screw to prevent inadvertent movement. Use the bit on the blade wrench to loosen the attachment screw. This allows the slides, to be pulled outward and the saw head to pivot past the 45º mark. Be sure to retighten the attachment screw when finished.
Rail Lock Knob (Fig. A)
The rail lock knob 29 allows you to lock the saw head firmly to keep it from sliding on the rails. This is necessary when making certain cuts or when transporting the saw.
Depth Stop (Fig. A)
The depth stop 24 allows the depth of cut of the blade to be limited. The stop is useful for applications such as grooving and tall vertical cuts. Rotate the depth stop forward and adjust the depth adjustment screw 28 to set the desired depth of cut. To secure the adjustment, tighten the wing nut 20. Rotating the depth stop to the rear of the saw will bypass the depth stop feature. If the depth adjustment screw is too tight to loosen by hand, the provided blade wrench can be used to loosen the screw.
Lock Down Pin (Fig. A)
The lock down pin should be used only when carrying or storing the saw. NEVER use the lock down pin for any cutting operation.
To lock the saw head in the down position, push the saw head down, push the lock down pin 17 in and release the saw head. This will hold the saw head safely down for moving the saw from place to place. To release, press the saw head down and pull the pin out.
Automatic Electric Brake
Your saw is equipped with an automatic electric blade brake which stops the saw blade within 5 seconds of trigger release. This is not adjustable.
On occasion, there may be a delay after trigger release to brake engagement. On rare occasions, the brake may not engage at all and the blade will coast to a stop.
If a delay or "skipping" occurs, turn the saw on and off 4 or 5 times. If the condition persists, have the tool serviced by an authorized DeWALT service center.
Always be sure the blade has stopped before removing it from the kerf. The brake is not a substitute for guards or for ensuring your own safety by giving the saw your complete attention.
To reduce the risk of serious personal injury, turn unit off and disconnect it from power source before making any adjustments or removing/installing attachments or accessories. An accidental start-up can cause injury.
Always use eye protection. All users and bystanders must wear eye protection that conforms to ANSI Z87.1 (CAN/CSA Z94.3).
Plug the saw into any household 60 Hz power source. Refer to the nameplate for voltage. Be sure the cord will not interfere with your work.
To reduce the risk of serious personal injury, ALWAYS use proper hand position as shown.
To reduce the risk of serious personal injury, ALWAYS hold securely in anticipation of a sudden reaction.
Proper positioning of your body and hands when operating the miter saw will make cutting easier, more accurate and safer. Never place hands near cutting area. Place hands no closer than 4" (100 mm) from the blade. Hold the workpiece tightly to the table and the fence when cutting. Keep hands in position until the trigger has been released and the blade has completely stopped. ALWAYS MAKE DRY RUNS (UNPOWERED) BEFORE FINISH CUTS SO THAT YOU CAN CHECK THE PATH OF THE BLADE. DO NOT CROSS ARMS, AS SHOWN IN FIGURE K3.
Keep both feet firmly on the floor and maintain proper balance. As you move the miter arm left and right, follow it and stand slightly to the side of the saw blade. Sight through the guard louvers when following a pencil line.
To turn the saw on, push the lock-off lever 40 to the left, then depress the trigger switch 1. The saw will run while the switch is depressed. Allow the blade to spin up to full operating speed before making the cut. To turn the saw off, release the switch. Allow the blade to stop before raising the saw head. There is no provision for locking the switch on. A hole 50 is provided in the trigger for insertion of a padlock to lock the switch off.
Always be sure the blade has stopped before removing it from the kerf.
Your saw has a built-in dust port 15 that allows either the supplied dust bag or a shop vacuum system to be connected.
NOTE: This saw has a dust port equipped with an AirLockTM fitting, which is a universal system that connects tools to dust extraction shrouds to minimize cleanup on the jobsite.
To Attach the Dust Bag
(Fig. A)
If the slide feature is not used, ensure the saw head is pushed back as far as possible and the rail lock knob is tightened. This will prevent the saw from sliding along its rails as the workpiece is engaged.
NOTE: Although this saw will cut wood and many non-ferrous materials, we will limit our detailed discussion to the cutting of wood only. The same guidelines apply to the other materials. DO NOT CUT FERROUS (IRON AND STEEL) MATERIALS OR MASONRY WITH THIS SAW. Do not use any abrasive blades.
NOTE: Refer to Guard Actuation and Visibility in the Assembly and Adjustments section for important information about the lower guard before cutting.
(Fig. A, N)
A crosscut is made by cutting wood across the grain at any angle. A straight crosscut is made with the miter arm at the zero degree position. Set and lock the miter arm at zero, hold the wood firmly on the table and against the fence. With the rail lock knob tightened, turn on the saw by squeezing the trigger switch 1 shown in Figure A.
When the saw comes up to speed (about 1 second) lower the arm smoothly and slowly to cut through the wood. Let the blade come to a full stop before raising arm.
When cutting anything larger than a 2 x 8 (51 x 203 mm [2 x 6 (51 x 152) at 45º miter]) use an out-down-back motion with the rail lock knob loosened. Pull the saw out, toward you, lower the saw head down toward the workpiece, and slowly push the saw back to complete the cut. Do not allow the saw to contact the top of the workpiece while pulling out. The saw may run toward you, possibly causing personal injury or damage to the workpiece.
Cutting of multiple pieces is not recommended but can be done safely by ensuring that each piece is held firmly against the table and fence.
NOTE: To provide greater crosscut capacity with reduced stroke, the blade on the DWS779 extends deeper into the table. As a result, a greater lifting force on the workpiece may be experienced during the cut.
Always use a work clamp to maintain control and reduce the risk of workpiece damage and personal injury, if your hands are required to be within 4" (100 mm) of the blade during the cut.
NOTE: The rail lock knob 29 shown in Figure A must be loose to allow the saw to slide along its rails 23.
Miter crosscuts are made with the miter arm at some angle other than zero. This angle is often 45º for making corners, but can be set anywhere from zero to 50º left or 60° right. Make the cut as described above.
When performing a miter cut on workpieces wider than a 2 x 6 that are shorter in length, always place the longer side against the fence 10.
To cut through an existing pencil line on a piece of wood, match the angle as close as possible. Cut the wood a little too long and measure from the pencil line to the cut edge to determine which direction to adjust the miter angle and recut. This will take some practice, but it is a commonly used technique.
A bevel cut is a crosscut made with the saw blade leaning at an angle to the wood. In order to set the bevel, loosen the bevel lock knob 11, and move the saw to the left or right as desired. (It is necessary to move the fence to allow clearance.) Once the desired bevel angle has been set, tighten the bevel lock knob firmly. Refer to the Controls section for detailed instructions on the bevel system.
Bevel angles can be set from 49º right to 49º left and can be cut with the miter arm set between 50º left or 60º right. At some extreme angles, the right or left side fence might have to be removed. To remove the left or right fence, unscrew the fence adjustment knob 14 several turns and slide the fence out.
NOTE: Refer to Fence Adjustment in the Assembly and Adjustments section for important information on adjusting the fences for certain bevel cuts.
The smoothness of any cut depends on a number of variables. Things like material being cut, blade type, blade sharpness and rate of cut all contribute to the quality of the 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.
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.
For varied cutting applications, refer to the list of recommended saw blades for your saw and select the one that best fits your needs. Refer to Saw Blades under Accessories.
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.
(Fig. A)
Refer to Depth Stop for detailed instructions for setting depth of cut. A piece of scrap wood should be used to verify the desired depth of cut.
Hold the wood firmly on the table and against the fence 10. Align the cut area underneath the blade. Position the saw arm fully forward, with blade in down position. Turn on the saw by squeezing the trigger switch 1 shown in Figure A. Smoothly, push saw arm rearward to cut a groove through the workpiece.
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.
To widen the groove, repeat steps 1–4 until the desired width is obtained.
(Fig. A)
To reduce the risk of serious personal injury, turn off the tool and disconnect it from the power source before attempting to move it, change accessories or make any adjustments.
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.
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.
Always use a work clamp to maintain control and reduce the risk of workpiece damage and personal injury.
If you cannot secure the workpiece on the table and against the fence by hand, (irregular shape, etc.) or your hand would be less than 4" (100 mm) from the blade, a clamp or other fixture must be used.
For best results use the vertical material clamp 21 provided with your saw. Additional DW7082 clamps can be purchased at your local retailer or DeWALT service center.
Other aids such as spring clamps, bar clamps or C-clamps may be appropriate for certain sizes and shapes of material. Use care in selecting and placing these clamps. Take time to make a dry run before making the cut. The left fence will slide from side to side to aid in clamping
(Fig. A)
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.
To reduce the risk of serious personal injury, turn off the tool and disconnect it from the power source before attempting to move it, change accessories or make any adjustments.
ALWAYS SUPPORT LONG PIECES.
Never use another person as a substitute for a table extension; as additional support for a workpiece that is longer or wider than the basic miter saw table or to help feed, support or pull the workpiece.
For best results, use the DW7080 extension work support to extend the table width of your saw, available from your dealer at extra cost.
Support long workpieces using any convenient means such as sawhorses or similar devices to keep the ends from dropping.
To best understand how to make the items listed here, we suggest that you try a few simple projects using scrap wood until you develop a "feel" for your saw.
Your saw is the perfect tool for mitering corners like the one shown in Figure O. Sketch 1 in Figure P shows a joint made by using the bevel adjustment to bevel the edges of the two boards at 45º each to produce a 90º corner. For this joint the miter arm was locked in the zero position and the bevel adjustment was locked at 45º. The wood was positioned with the broad flat side against the table and the narrow edge against the fence. The cut could also be made by mitering right and left with the broad surface against the fence.
Sketch 2 in Figure P shows a joint made by setting the miter arm at 45º to miter the two boards to form a 90º corner. To make this type of joint, set the bevel adjustment to zero and the miter arm to 45º. 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 P are for four-sided objects only.
As the number of sides changes, so do the miter and bevel angles. The chart below gives the proper angles for a variety of shapes.
EXAMPLES
NUMBER OF SIDES | MITER OR BEVEL ANGLE |
4 | 45° |
5 | 36° |
6 | 30° |
7 | 25.7° |
8 | 22.5° |
9 | 20° |
10 | 18° |
The chart assumes that all sides are of equal length. For a shape that is not shown in the chart, use the following formula: 180º divided by the number of sides equals the miter (if the material is cut vertically) or bevel angle (if the material is cut laying flat).
A compound miter is a cut made using a miter 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 Q.
NOTE: If the cutting angle varies from cut to cut, check that the bevel lock knob and the miter lock handle are securely locked. These must be locked after making any changes in bevel or miter.
The chart at the end of this manual (Table 1) will assist you in selecting the proper bevel and miter settings for common compound miter cuts. To use the chart, select the desired angle A (Fig. Q, Angle A+Exteriors Angles = 90°) 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 miter angle.
Set your saw to the prescribed angles and make a few trial cuts. Practice fitting the cut pieces together until you develop a feel for this procedure and feel comfortable with it.
EXAMPLE: To make a 4 sided box with 65° exterior angles(Figure Q), 25°(Angle A) = 90° – 65°(Exteriors Angles), use the upper right arc. Find 25° on the arc scale. Follow the horizontal intersecting line to either side to get miter angle setting on saw (23°). Likewise, follow the vertical intersecting line to the top or bottom to get the bevel angle setting on the saw (40°). Always try cuts on a few scrap pieces of wood to verify settings on saw.
ALWAYS MAKE A DRY RUN WITHOUT POWER BEFORE MAKING ANY CUTS.
Straight 90° cuts:
Position the wood against the fence and hold it in place as shown in Figure R. Turn on the saw, allow the blade to reach full speed and lower the arm smoothly through the cut.
(Fig. R)
Position material as shown in Figure R.
All cuts should be made with the back of the molding against the fence and with the bottom of the molding against the table.
Inside corner | Outside corner | |
Left side |
|
|
Right side |
|
|
Material up to 6.5" (165 mm) can be cut as described above.
Your miter saw is better suited to the task of cutting crown molding than any tool made. In order to fit properly, crown molding must be compound mitered with extreme accuracy.
The two flat surfaces on a given piece of crown molding are at angles that, when added together, equal exactly 90°. Most, but not all, crown molding has a top rear angle (the section that fits flat against the ceiling) of 52° and a bottom rear angle (the part that fits flat against the wall) of 38°. Your miter saw has special pre-set miter latch points at 31.6° left and right for cutting crown molding at the proper angle. There is also a mark on the bevel scale at 33.9°.
The chart below gives the proper settings for cutting crown molding. (The numbers for the miter and bevel settings are very precise and are not easy to accurately set on your saw.) Since most rooms do not have angles of precisely 90º, you will have to fine tune your settings anyway. PRETESTING WITH SCRAP MATERIAL IS EXTREMELY IMPORTANT!
(Fig. A, S)
Inside corner | Outside corner | |
Left side |
|
|
Right side |
|
|
When setting bevel and miter angles for all compound miters, remember that:
The angles presented for crown moldings are very precise and difficult to set exactly. Since they can easily shift slightly and very few rooms have exactly square corners, all settings should be tested on scrap molding.
PRETESTING WITH SCRAP MATERIAL IS EXTREMELY IMPORTANT!
Place the molding on the table at an angle between the sliding fence 10 and the saw table 16, as shown in Figure T. Use of the crown molding fence accessory (DW7084) is highly recommended because of its degree of accuracy and convenience. The crown molding fence accessory is available for purchase from your local dealer.
The advantage to cutting crown molding using this method is that no bevel cut is required. Minute changes in the miter angle can be made without affecting the bevel angle. This way, when corners other than 90° are encountered, the saw can be quickly and easily adjusted for them. Use the crown molding fence accessory to maintain the angle at which the molding will be on the wall.
Inside corner | Outside corner | |
Left side |
|
|
Right side |
|
|
NEVER MAKE ANY CUT UNLESS THE MATERIAL IS SECURED ON THE TABLE AND AGAINST THE FENCE.
(Fig. A, U, V)
ALWAYS USE THE APPROPRIATE SAW BLADE MADE ESPECIALLY FOR CUTTING ALUMINUM. These are available at your local DeWALT retailer or DeWALT service center. Certain workpieces, due to their size, shape or surface finish, may require the use of a clamp or fixture to prevent movement during the cut. Position the material so that you will be cutting the thinnest cross section, as shown in Figure U. Figure V illustrates the wrong way to cut these extrusions.
Use a stick wax cutting lubricant when cutting aluminum. Apply the stick wax directly to the saw blade 39 before cutting. Never apply stick wax to a moving blade.
The wax, available at most hardware stores and industrial mill supply houses, provides proper lubrication and keeps chips from adhering to the blade. Be sure to properly secure workpiece.
Refer to Saw Blades under Accessories for correct saw blade.
When cutting bowed material always position it as shown in Figure W and never like that shown in Figure X. Positioning the material incorrectly will cause it to pinch the blade near the completion of the cut.
Plastic pipe can be easily cut with your saw. It should be cut just like wood and CLAMPED OR HELD FIRMLY TO THE FENCE TO KEEP IT FROM ROLLING. This is extremely important when making angle cuts.
Occasionally you will encounter a piece of wood a little too large to fit beneath the lower guard. If this occurs, simply place your right thumb on the upper side of the guard and roll the guard up just enough to clear the workpiece, as shown in Figure Y. Avoid doing this as much as possible, but if need be, the saw will operate properly and make the bigger cut. NEVER TIE, TAPE, OR OTHERWISE HOLD THE GUARD OPEN WHEN OPERATING THIS SAW.
To reduce the risk of serious personal injury, turn unit off and disconnect it from power source before making any adjustments or removing/installing attachments or accessories. An accidental start-up can cause injury.
To reduce the risk of serious personal injury, DO NOT touch the sharp points on the blade with fingers or hands while performing any maintenance.
DO NOT use lubricants or cleaners (particularly spray or aerosol) in the vicinity of the plastic guard. The polycarbonate material used in the guard is subject to attack by certain chemicals.
(Fig. Z, AA)
The belt is designed to last the life of the tool. However, abuse of the tool could cause the belt to fail.
If the blade does not turn when the motor is running, the belt has failed. To inspect or replace the belt, remove the belt cover screws 49. Remove the belt cover 55. Inspect the ribs of the belt for wear or failure. Check belt tension by squeezing the belt as shown in Figure AA. The belt halves should almost touch when squeezing firmly with the thumb and index finger. To adjust the tension, loosen, but do not remove, the four crosshead screws 56. Then rotate the set screw 57 on the top of the motor plate casting until the proper tension is achieved. Tighten the four screws securely and replace the belt cover.
NOTICE: Overtightening the belt will cause premature motor failure.
Blow dirt and dust out of all air vents with clean, dry air at least once a week. To minimize the risk of eye injury, always wear ANSI Z87.1 approved eye protection when performing this procedure.
Never use solvents or other harsh chemicals for cleaning the non-metallic parts of the tool. These chemicals may weaken the plastic materials used in these parts. Use a cloth dampened only with water and mild soap. Never let any liquid get inside the tool; never immerse any part of the tool into a liquid.
Depending on your cutting environment, saw dust can clog the dust duct and may prevent dust from flowing away from the cutting area properly. With the saw unplugged and the saw head raised fully, low pressure air or a large diameter dowel rod can be used to clear the dust out of the dust duct.
Since accessories, other than those offered by DeWALT, have not been tested with this product, use of such accessories with this tool could be hazardous. To reduce the risk of injury, only DeWALT recommended accessories should be used with this product.
Recommended accessories for use with your tool are available at extra cost from your local dealer or authorized service center. If you need assistance in locating any accessory, please contact DeWALT Industrial Tool Co., 701 East Joppa Road, Towson, MD 21286, call 1-800-4-DeWALT (1-800-433-9258) or visit our website: www.dewalt.com.
Optional Accessories
The following accessories, designed for your saw, may be helpful. Use care in selecting and using accessories.
Extension Work support: DW7080
Used to support long overhanging workpieces, the work support is user assembled. Your saw base is designed to accept two work supports, one on each side.
Adjustable length stop: DW7051
Requires the use of one Extension Work Support (DW7080). It is used to make repetitive cuts of the same length from 0 to 42" (107 cm).
Clamp: DW7082
Used for firmly clamping workpiece to the saw fence for precision cutting.
Dust Bag: DW7053
Equipped with a zipper for easy emptying, the dust bag will capture the majority of the sawdust produced.
Crown Molding Fence: DW7084
Used for precision cutting of crown molding.
Saw Blades
ALWAYS USE 12" (305 mm) SAW BLADES WITH 1" (25.4 mm) ARBOR HOLES. SPEED RATING MUST BE AT LEAST 4800 RPM. Never use a smaller diameter blade. It will not be guarded properly. Use crosscut blades only! Do not use blades designed for ripping, combination blades or blades with hook angles in excess of 7˚.
To assure product SAFETY and RELIABILITY, repairs, maintenance and adjustment (including brush inspection and replacement, when applicable) should be performed by a DeWALT factory service center or a DeWALT authorized service center. Always use identical replacement parts.
Thank you for your purchase. Register your product now for:
Register online at www.dewalt.com/register.
BE SURE TO FOLLOW SAFETY RULES AND INSTRUCTIONS
TROUBLE! | WHAT'S WRONG? | WHAT TO DO |
Saw will not start | Saw not plugged in | Plug in saw. |
Fuse blown or circuit breaker tripped | Replace fuse or reset circuit breaker. | |
Cord damaged | Have cord replaced by authorized service center. | |
Brushes worn out | Have brushes replaced by authorized service center. | |
Saw makes unsatisfactory cuts | Dull blade | Replace blade. Refer to Changing or Installing a New Saw Blade. |
Blade mounted backwards | Turn blade around. Refer to Changing or Installing a New Saw Blade. | |
Gum or pitch on blade | Remove blade and clean with turpentine and coarse steel wool or household oven cleaner. | |
Incorrect blade for work being done | Change the blade type. Refer to Saw Blades under Accessories. | |
Blade does not come up to speed | Extension cord too light or too long | Replace with adequate size cord. Refer to Additional Safety Rules for Miter Saws. |
Low house current | Contact your electric company. | |
Machine vibrates excessively | Saw not mounted securely to stand or work bench | Tighten all mounting hardware. Refer to Bench Mounting. |
Stand or bench on uneven floor | Reposition on flat level surface. Refer to Familiarization. | |
Damaged saw blade | Replace blade. Refer to Changing or Installing a New Saw Blade. | |
Does not make accurate miter cuts | Miter scale not adjusted correctly | Check and adjust. Refer to Miter Scale Adjustment under Assembly and Adjustments. |
Blade is not square to fence | Check and adjust. Refer to Miter Scale Adjustment under Assembly and Adjustments. | |
Blade is not perpendicular to table | Check and adjust fence. Refer to Bevel Square to Table under Assembly and Adjustments. | |
Workpiece moving | Clamp workpiece securely to fence or glue 120 grit sandpaper to fence with rubber cement. | |
Material pinches blade | Cutting bowed material | Refer to Bowed Material under Special Cuts. |
TABLE 1: COMPOUND MITER CUT
(POSITION WOOD WITH BROAD FLAT SIDE ON THE TABLE AND THE NARROW EDGE AGAINST THE FENCE)
If you have questions or comments, contact us.
1-800-4-DeWALT
www.DeWALT.com
Here you can download full pdf version of manual, it may contain additional safety instructions, warranty information, FCC rules, etc.
Advertisement
Need help?
Do you have a question about the DWS779 and is the answer not in the manual?
Questions and answers