DeWALT DWS779 vs. DWS780 miter saw — What’s the difference? Everything you need to know. The truth is, there isn’t much difference between the two miter saws, and the DeWALT DWS779 has been discontinued but it’s still available at the time of this writing on Amazon. The reality is, the DWS780 is definitely better so don’t worry about the older DW779 being left behind by DeWalt.
INTRO | DeWALT DWS779 vs DWS780
A miter saw is a must-have tool if you are a serious DIY enthusiast. It’s the best alternative to the table saw’s miter function. All table saw users know how frustrating a table saw miter slide can be. Few are of good quality and tend to be inaccurate and difficult to use.
A popular alternative is to build a crosscut sled for your table saw. You will find excellent examples of this on the internet. Keeping in mind that you must have a table saw on site to be able to use it, this solution is not very convenient. I consider it a viable solution in the workshop at home when you are on a limited budget. For on-site work, like installing crown and base moldings, you cannot beat the Double bevel compound sliding miter saw. It’s lighter, more portable, and far more convenient than a table saw. It also beats using any circular or track saw for these installations.
To tradespeople, the miter saw is one of the must-have tools on a jobsite. The miter saw is also known as a drop saw in the trade. It is used to make quick, accurate crosscuts in workpieces at selected angles. An alternative to the miter saw is a circular saw, but it is more difficult to use and less accurate. The miter is invaluable when used to for cutting moldings and trim. It is a task that requires the most accurate cuts possible, and requires that you maintain the same accuracy all day.
The miter saw is accurate, and easy to set up and use. A miter saw is not exclusively used to cut moldings. You use it for door frames, window trimming, picture framing, and a lot more. DeWALT has become synonymous with quality tools. They are a popular choice internationally. The DeWALT miter saws are no exception and are renowned for accurate, clean cuts for years on end.
Before I introduce and compare the DeWALT DWS779 and DWS780 saws, we should divert a little. For those of us who do not fully understand the miter saw variants, a quick review of terms used is in order. What’s the difference between a miter, compound miter, double-bevel-compound miter, and a double-bevel-compound-sliding miter saw? Which one should one buy?
DeWALT DWS779 | *Discontinued for the improved DWS780
A miter or chop saw can make cuts at a variety of angles. You pull the blade down onto the workpiece and cut it. The blade cannot tilt to cut a bevel. It moves through one plane only, at 90° to the base. This type of saw can only make miter cuts.
To make miter and bevel cuts, you need a compound miter saw. This can be a single bevel or double bevel compound miter saw. On the single bevel compound miter saw, the cutting arm can pivot to the left or right only, not both. With this type of saw, you can cut crown moldings or picture frames and any miter cut that requires cutting on two planes.
On a double bevel, compound miter saw the blade pivots left and right for angled cuts and tilts in both directions for beveled cuts. These miter saws are called compound or double compound miter saws. The compound miter saw is limited in the length of its cut. A 12-inch compound miter saw can only cut material up to 5.5 inches wide. It allows you to cut a deck board (6″ wide) at right angles, using one cut. When you have to make a 45°miter cut, you will not be able to cut all the way through. You will need to flip the lumber over, swing the saw to the other side and re-align the cut line. If you work with great care, you can make an acceptable clean cut.
Shared Features of the DeWALT DWS780 and the DWS779
A 10″ double bevel, compound miter saw fitted with a fine cut 60 tooth blade will most likely make the best miter cuts. It will be a more suitable solution for picture framing, and will save you some money. Blades are cheaper to buy and sharpen, and the blade is less prone to flexing and “spreading” the kerf. For greater flexibility of use and convenience, you cannot beat the 12″ double bevel, compound sliding miter saw.
This limited cut length is the reason the Double bevel compound sliding miter saw came to be. With this type of machine, you can do a 45° miter cut on 2×12 dimensional lumber in one go with a 12″ blade. In this review of the DeWALT DWS779 vs. DWS780, you will find a way of making the cut even wider. I will discuss three sliding compound DeWALT miter saws: DeWALT DWS779 and DWS780 models. The DWS780 replaces the DWS779 and has an additional convenience. I discuss the two excellent tools in one review and point out why you should still consider the DWS779 while it is available. I also introduce the DeWALT DHS790AT2 FLEXVOLT which is the same saw but powered by DeWALT’s improved battery system.
Miter Saws we Review :
- DeWALT DWS779 — 12″ Sliding Compound Miter Saw
- DeWalt DWS780 — 12-Inch Double Bevel Sliding Compound Miter Saw
- DeWALT DHS790AT2 FLEXVOLT — 12″, Battery-powered, 120V MAX*-Double bevel compound sliding miter (with 2 Flexvolt batteries and fast charger)
DeWALT DWS779 vs. the DWS780 — Miter Saws
12-Inch Double Bevel Sliding Compound Miter Saw.
- Integrated CUTLINE Blade Positioning System provides adjustment free cut line indication for better accuracy and visibility
- Powerful 15 amp, 3,800 rpm motor delivers extended power and durability
- Super efficient dust collection system captures over 75% of dust generated
- Tall sliding fences support crown molding up to 7-1/2 in. nested and base molding up to
- 6-3/4 in. vertically against the fence while easily sliding out of the way for bevel cuts
- Exclusive back fence design cuts up to 2×16 dimensional lumber at 90° and 2×12 at 45°
- Adjustable stainless steel miter detent plate with 10 positive stops improves productivity and ensures cutting accuracy
- Miters 60° to the right and 50° to the left providing increased capacity
- Oversized bevel scale makes bevel angle adjustments accurate and easy
- Compact, lightweight design (56 lbs.) allows for easy transport and storage
- Cam lock miter handle with detent override deliver quick and accurate miter angles
- Dual horizontal steel rails with innovative clamping mechanism and linear ball bearings deliver an accurate, durable and compact saw
- Innovative gearbox and belt-drive design increases vertical cutting capacity
- Precise miter system and machined base fence support optimize durability and cutting accuracy
The DeWALT DWS779 is now discontinued and selling at a reduced price. It was replaced by the DWS780 which is the updated model with some additional features. Unlike the DWS780, the DWS779 does not have the XPS light that indicates the cut line on the workpiece. This XPS cutline projects a shadow of the blade onto the piece so that you can see where the blade will cut. It’s a fantastic idea because previous laser cutline indicators tended to go out of alignment after a while. They seemed like a good idea, but this shadow cutline will never be wrong.
The good news is that you can buy an XPS cutline kit for the DWS779 from DeWALT. It’s easy to install and worth the effort. This XPS cutline is the only difference in functionality between the DWS779 and the DWS780. From the advertised specs, there seems to be a weight difference. The DWS780 being 11 pounds lighter than the DWS779. There is no indication whether this is true or how it was achieved, possibly the 67 pounds is its shipping weight.
The DWS779 sells at a lower price than the DWS780. If you feel the shadow cutting line is not worth an additional $200 or so, the older model is highly recommended. Apart from the light, it is the same model with the same features and capabilities.
The DWS779 power source is a 15 Amp corded motor, delivering ample power and runs at 3,800 rpm. To achieve the smoothest cuts on moldings and other precision work, I recommend a sharp 60 tooth carbide tipped blade. Also cut slower at an even rate. Included with the saw, is a material clamp similar to the DW7082 accessory. I recommend using it to prevent material moving or creeping during a cut.
The DeWALT can cut up to 2×16 dimensional lumber at 90° due to the back fence design and 2×12’s at 45°. You use a special set-up by making a higher platform. The plan is to use a platform made from 1.5 inch thick particleboard or similar material, and cut it to 14.5 x 26 inches. You have to remove both left and right sliding fences. Mount the platform to the saw, and cut the workpiece on the platform that you have mounted to the table. It enables you to use a wider through section of the blade at the expense of losing some depth of cut. This whole procedure is explained in detail in the user’s manual.
The efficient dust collection system uses a bag to collect most of the dust generated, although most users recommend using a dust collector instead. Users that use a dust collector or vacuum cleaner say it keeps the sliding bars and the rear of the machine cleaner. It will increase the lifespan of the bearing seals that tend to collect dust and wear out.
Bevel angles can be set from 49° left to 49° right. While doing bevel cuts, you can also do miter cuts of up to 50° left or 60° right. It may be necessary to remove the right or left side fence to cut some compound angles. Fortunately, this is easy. You simply unscrew the fence adjustment knob several turns and slide the fence out.
The saw is accurate when you receive it. Should any of the settings be out, it is easy to adjust. The miter 0° position can be adjusted in relation to the miter latch by releasing four screws, and setting the miter position. The miter pointers and scale can also be adjusted. All the adjustments are explained in detail in the user’s manual.
To align the blade square to the table, you first loosen the 0° bevel lock. Then adjust a bevel adjustment screw with the blade wrench, so that the blade is at 0° bevel to the table. The bevel pointers can also be adjusted. You loosen each screw that holds each bevel pointer in place and move them as necessary. The bevel stop 45° right and left adjustment is a little more complex, but the instructions in the manual are detailed and logical.
Adjusting the kerf plates closer to the blade is easy to do. Then you cut them slowly with the saw blade to give the smallest gap possible between the blade and the kerf plates. It surprised me that you can adjust the rail guides for zero play to ensure accurate cuts.
You can cut a crown molding up to 7-1/2″ nested between the sliding fence and the optional DW7084 crown molding fence. A base molding up to 6-3/4″ fits vertically against the fence for easy miter cuts. You can also make a fitting for crown molding cuts from scrap particleboard or similar materials.
An alternative method for cutting crown moldings, is to bevel cut the molding on the table. I highly recommend the use of the crown molding fence accessory or your own version. It is more accurate and convenient. You can get the crown molding fence accessory from any DeWalt dealership.
The saw has an automatic electric blade brake. It stops the blade within 5 seconds of releasing the trigger. Unfortunately, the brake is not adjustable. DeWALT recommends monitoring it and having the saw serviced if it should stop working.
Although the saw can cut bevels up to 49°, you first have to push the bevel override-levers rearward, and out of the way. To use the 45° stops, pull the bevel override levers forward.
The DWS779 is backed by DeWALT’s same three-year limited warranty as the more recent DWS780.
Both the DWS779 and the DWS780 are excellent and capable compound sliding miter saws, suitable for any crosscut work. If you do not consider a corded miter saw as a limitation then this saw is ideal. Should you prefer a battery operated model with as much power and the same abilities, then the next one is for you.
DeWALT DHS790AT2 FLEXVOLT
Includes : 2x FlexVolt Batteries & a Fast Charger. You’ll be impressed with this powerful 120V battery-powered miter saw by FlexVolt. Work anywhere in an ultra-portable package.
- Flexible power options – corded or cordless
- Accuracy – CUTLINE™ blade positioning system and highly visible miter and bevel scales
- Runtime – Up to 289 cross cuts in 3-1/4 in. base molding
- Portability – Compact design weighs only 56lbs.
- Ultimate power flexibility providing the convenience of cordless with the performance of corded
- A powerful 120V brushless motor provides long run-time compared to brushed motors
- Integrated adjustment-free Cutline Blade Positioning System for accuracy and visibility
- High visibility bevel scale makes bevel angle adjustments accurate and easy
- Tall sliding fences support crown molding up to 7-1/2″ nested and base molding up to 6-3/4″ vertically against the fence
- Adjustable stainless steel miter detent plate with 11 detents, 60 degrees to the right and 50 degrees to the left providing increased capacity
Includes : DHS790 Miter Saw, 2x FLEXVOLT 20V/60V MAX* Batteries, Dual Port Fast Charger, DCA120 120V MAX* Corded Power Supply, 12 in. Blade, Blade Wrench, Dust Bag
The DeWALT DHS790AT2 FLEXVOLT is the same saw as the DWS780 and DWS779 with a different power pack. Instead of the normal corded 15 Amp motor, a battery-driven brushless motor drives the blade. This change makes it even more powerful than the corded tools, and the blade runs at the same speed as the DWS780 (3,800 RPM).
With the DHS790AT2 FLEXVOLT, you are free to tackle the job anywhere. There’s no need to rely on a generator or utility power. But, is it powerful enough to do any of the framing and finishing tasks, or building decks? Will the batteries last long enough and should utility power be available, can I use it?
VIDEO | DeWALT FlexVolt Miter Saw — DHS790AT2
This saw uses the 120V MAX FLEXVOLT system, and they supply two batteries with it. This battery system automatically switches to suit the voltage demand of the tool in which it is inserted. You get maximum runtime when using it with 20V MAX* tools and more power with 60V MAX* and 120V MAX tools. In 120V tools, you use two 60V MAX batteries which together gives you the 120 Volts. This flexibility is possible due to the internal construction of the battery pack. It is a wonderful battery that is compatible with older 20 Volt DeWALT tools, yet it is used extensively in the modern 120 Volt tools. Currently, you have a choice between 9Ah FLEXVOLT batteries and the same sized 12.0Ah.
Tech Specs :
- 45° Bevel Cut Capacity (dimensional lumber) : 2×14″ (2×16″ with back fence)
- 45° Miter Cut Capacity (Max Height) : 4″
- 45° Miter Cut Capacity (Max Width) : 8″
- 90° Cross-Cut Capacity (dimensional lumber) : 2×14″ (2×16″ with back fence) in
- 90° Cross-Cut Capacity (Max Width) : 16″
- Amps : 15 Amps
- Arbor Size : 1″ in
- Blade Diameter : 12″
- For Metal Cutting : no
- For Wood Cutting : true
- Handle Type Top : Handle
- Horizontal Capacity: Baseboard Lying Flat : 16″ in
- Horizontal Capacity: Crown Molding Lying Flat : 13-3/4″ in
- No Load Speed : 3800 rpm
- Power Tool Type : Cordless
- Tool Height : 23 in
- Tool Length : 32 in
- Tool Weight : 56 lbs
- Type of Miter Saw : Slide
- Vertical Capacity: Baseboard Against Fence : 6-3/4″ in
- Vertical Capacity: Crown Molding Vertically Nested : 7-1/2″ in
How the FLEXVOLT 20V MAX switches to 60 Volt
The following information is not based on marketing material, but on information gained from dismantling a battery pack. Much was written in the past explaining how the battery can switch from 20 Volt to 60 Volt by simply inserting it into another tool. As a result of my own experience and knowledge of battery packs, the various explanations did not satisfy my curiosity.
Many of the theories were based on information from DeWALT. However, the arrangement of the FlexVolt batteries are not the same as it is illustrated in the drawings and videos from DeWALT. The layout is completely different. The battery has three sets of battery cells, five cells in each group. So there are 15 battery cells in the battery. Each pack of 5 cells delivers 18.15 Volts nominal (20V), 18.15 divided by 5 gives you 3.63 Volt for each cell.
VIDEO | How DeWalt FlexVolt Batteries Work
When not inserted in a tool, the battery pack is an 18Volt nominal battery with the three battery packs in parallel. This arrangement gives you the maximum Ah rating. The tools have an arrangement of contacts and two actuators that switches the battery voltage. The 60 Volt tool has a different arrangement of terminals to the 20 Volt tool. A sliding switch actuator on the 60 Volt tool pushes the switch on the battery pack in all the way to enable the 60 Volt mode. In this mode, the three packs of 18.15 Volts are put in series to give you 54.45 Volts nominal. The voltages of a fully charged battery are higher than the nominal voltages and closer to 20 Volts and 60 Volts. The maximum charge for each cell is 4.2 Volts, so immediately after a charge, the battery pack reaches 21 Volts.
The DHS790AT2 uses two batteries in series so that the maximum voltage available is 120 Volts. The motor used to drive the tool is not a normal brushed DC electrical motor. It is a brushless, multipole motor that delivers more power, runs cooler, and has reduced internal losses. At the same time, it requires less battery energy, and delivers up to 57% more run time per charge. It is, therefore, more efficient and it has fewer wearing parts. The only mechanical wear is on the motor bearings.
The cordless arrangement gives you all the power you need, where you need it. It is no wonder that DeWALT uses it to power the same basic tool used in the DWS780 model. You have the same 12-inch blade and the same double bevel compound sliding miter saw. You even get the same CUTLINE blade positioning system that uses a bright LED light to cast a shadow of the blade on the work. Wonderful, the only questions that remain is how long the batteries last? What do you do when you run out of battery power?
6.0Ah Battery — DEWALT DCB606-2 20V MAX
The runtime with two batteries is up to 289 to 310 crosscuts in 3-1/4 inch baseboard molding. Is that enough? I don’t know, you decide. It depends on what you want to do with the tool. Tradesman considers the tool to be very powerful and a little faster and smoother than the DWS780. Workers that use it all day, find that you seldom run out of battery power during a workday.
Good news is that the FlexVolt batteries come with the DeWALT dual port fast charger. The fast charger does charge the batteries a lot faster than the standard charger. It charges a flat 20V 4 Ah battery in a little more than 33 minutes. To top it all, you also get a DC120A corded power supply that resembles a battery with a cord. It slides into the miter saw and powers it from the 120 Volt utility power for unlimited runtime. It does mean that instead of carrying one tool you haul the tool, two batteries, a charger, and the power supply.
I compared the specifications of the DHS790AT2 to the DWS780, and everything is the same. You get the same 2×16 dimensional lumber cuts at 90° and 2×12 inches at 45°. The same miter angles of 50° left and 60° right. The bevel angles and specifications are also the same. It is the same saw with a different power source.
DEWALT DHS790AT2 FLEXVOLT 120V | Battery Powered Miter Saw
The two corded DeWALT DWS779 and DWS780 and the cordless DHS790AT2 FLEXVOLT double bevel compound sliding miter saws are on an equal footing. All of them offer exceptional versatility and the renowned DeWALT quality of workmanship. I would be proud to own any one of them, but my personal favorite must be the DHS790AT2 FLEXVOLT model. Yes, it is more expensive than the corded models. However, it delivers more and that brushless motor will last forever. Many complaints that some batteries fail prematurely surfaced in the media and feedback columns. Even the best batteries do fail and can disappoint you, but you can rest assured that DeWALT will support you all the way.
Why do I need a double bevel compound sliding miter saw?
A double bevel compound sliding miter saw is the best tool for a variety of uses:
- It’s invaluable when doing crown trimmings
- The best tool to cut base moldings accurately
- To make regular board cuts like fitting a deck
- Angled, miter cuts when fitting into awkward corners
- General crosscut work such as flooring, paneling, etc.
- Trim work around doors and windows
- Cutting fence poles to length
For any of these tasks where a degree of accuracy and fast, convenient cuts are needed, you will benefit by using a miter saw. On most work sites, I notice that it is the first tool to be offloaded and readied. It is the most used and most versatile crosscut tool.
When skilled in using a circular saw, it is often used for quick, not so accurate cuts to shorten lumber. However, it is not easy to do accurate cuts with it. I find that it is a lot quicker and more accurate to use the miter saw. It may be because the saw is available and always ready. But most of the time, this is because the tool has accurate settings that are easy and quick to use. The cutline is fully visible, and lining it up with the blade is rapid and accurate.
A circular saw, on the other hand, has a hidden cut line that is difficult to see. It is hard to follow the line because you control the cut by hand and the saw tends to wander. It is possible to execute the cuts you do with a miter saw, but be warned, it’s difficult, slow and inaccurate.
With a miter saw, it is easy to line up the cut line. Even without the DeWALT shadow cutline or the laser guides that clearly show you where the cut is going to be. With the workpiece set against the fence, you move the handle down to see exactly where the blade will cut. I’ve done it for many years, and I never wished I had a laser guide. The absence of a cutline indicator will not deter me from purchasing the DWS779.
Bevel cuts cannot be done as easily on any other tool as on a sliding double bevel compound miter saw. Try doing repetitive angled bevel cuts on 1×10 lumber using a table saw. It’s not possible to do it as quickly and trouble-free, and a circular saw will never be as accurate. The quality of the cut will also be worse.
One advantage of using a miter saw is that the cut is always clean because the blade cuts down and the workpiece rests against the table. In addition to this, the fence supports it. It has almost no tendency to rip and splinter the one side of the cut as with a table saw, or circular saw.
Repeatable cuts to the same length can be done safely with a miter saw. You can do this with a table saw, but it is not safe. It can become dangerous when you cut short offcuts because you have to move the work through the blade and against the rip guide. Using a miter saw, you can safely butt your workpiece against a stop on one end of the work surface. The cut is safe because the work does not move, and it is quick and easy to feed it for the next cut. You can do mitered cuts, even compound cuts, repeatedly and more accurately than with any other tool. Except maybe for the radial arm saw. But these are expensive, especially compared to one of these miter saws. It is also not a portable tool, not nearly as portable as the DeWALT DHS790AT2 FLEXVOLT or even the DWS779 and the DWS780.