DeWalt 20 in. Variable-Speed Scroll Saw

Why I reached for this scroll saw

I added the DW788 to my bench to handle larger fretwork, inlay, and inside-cut projects that outgrew my benchtop saw. I wanted a 20-inch throat, true variable speed, low vibration, and fast blade threading. After weeks of cutting everything from 1/8-inch Baltic birch to 2-inch cherry and thin aluminum sheet, I have a clear sense of where this saw shines—and where it asks for a bit of patience or a tweak.

Build, layout, and first impressions

The core of this saw’s appeal is its double parallel-link arm. It’s the right design for minimizing front-to-back blade motion and isolating vibration. Mounted to a sturdy stand and properly leveled, the DW788 runs impressively smooth and quiet for its size. My dial indicator isn’t lab-grade, but cut quality tells the tale: tight-radius turns feel controlled, and the blade tracks true with far less washboard effect than C-arm designs.

The table is a big, flat slab of cast iron that bevels 45 degrees both left and right. It’s substantial and stays put once locked, though the under-table bevel lock could stand a slightly beefier knob. The footprint is compact for a 20-inch saw, but don’t let that fool you—at 56 pounds, most of that mass is in the table. Plan to bolt it down; it’s worth the stability.

Front-mounted controls are a win. The on/off switch, variable-speed dial (400–1,750 SPM), tension lever, and dust blower are all right where your hands naturally fall. Power is modest on paper (1.3 A), but scroll work is about control, not brute force. Within its 3/4-inch stroke, the motor has plenty of torque for hardwoods at the lower end of the speed range and for intricate veneers at the high end.

Blade changes and inside cuts

Tool-free blade clamps are the promise here, and they do make life easier—up to a point. For standard wood blades (say, #3 to #7), the clamps hold securely and threading the blade through an inside cut is quick once you get the choreography down: drop tension, lift the arm, clamp bottom, clamp top, tension, and go.

Two caveats:

• Bottom visibility: There’s only a narrow slot in the table, no removable insert, and the lower clamp sits behind a small guard. You end up working by feel. After a few days it became muscle memory, but the learning curve is real. A small magnetic LED under the table helps, as does a handheld inspection mirror when you’re starting out.
• Thin blades and metals: Ultra-thin blades (for thin aluminum or tight fretwork) can slip in the stock clamps if your technique isn’t spot-on. Degreasing the clamp faces, lightly scuffing them with 600-grit, and ensuring blades are oil-free improved holding power for me. On aluminum, a slower speed with a touch of lubricant reduces chatter and unloading forces on the blade, which also helps.

If you do a lot of metal fretwork with fine blades, an aftermarket clamp set with larger, more positive contact surfaces made a noticeable difference in my shop. With that swap, slips essentially disappeared.

The arm lifts to thread blades for internal cuts, but it doesn’t stay up on its own. That’s not a defect; it’s how the geometry maintains alignment under tension. You’ll need to drop tension to lift the arm, and you may find yourself wishing for a third hand. My fix was simple: a small shop-made prop that nests under the arm, and later, a dedicated arm-lift accessory. Either approach speeds up piercing work tremendously.

Accuracy and cut quality

This saw’s calling card is how predictably it cuts. The arm geometry keeps the blade perpendicular through the stroke, so kerfs stay square and patterns register cleanly. On 1/2-inch hardwood, I can sneak up to a knife line and the blade doesn’t wander if I let the teeth do the work. Compound cuts and stack cutting also benefit from the low vibration—parts stay aligned, and you don’t fight the stock.

• Wood: With the table waxed and the speed around 700–900 SPM for hardwoods, I get clean edges and minimal fuzz. At max speed, the saw is gentle enough for delicate veneers without grabbing.
• Plastics: Slow down, use a fine-tooth blade, and let the blower do its job; edges stay crisp with less melting than I expected.
• Thin aluminum: The saw will handle 1/8-inch aluminum, but you’ll want a slower stroke, a skip-tooth or metal-cutting blade, and a dab of cutting wax. Any tendency for the stock hold-down to chatter becomes more apparent here; I usually swing the hold-down out of the way and rely on steady hand pressure and proper tension.

Maximum capacity is 2 inches at 90 degrees, and it will do it, though efficiency improves with an aggressive blade and moderate feed pressure. The variable speed range is genuinely useful: it’s broad enough that you can match the application rather than feeling like you’re picking between “too slow” and “too fast.”

Ergonomics and workflow

• Controls: The front-facing tension lever encourages good habits. I flick tension off for every blade thread, which prolongs blade life and keeps the arm geometry consistent.
• Table bevel: It’s accurate and repeatable, but I recommend checking 90 degrees with a small engineer’s square and setting your own zero. Once dialed in, it holds fine.
• Dust management: There’s a flexible blower to clear the cut line. It works, but the modular plastic line is fragile. Mine developed a crack near the tip early on; it’s a cheap part and easy to replace, and swapping to a higher-quality section of modular hose makes it a non-issue. There’s no built-in dust collection port, so add a small hood and a shop vac if you’re volume cutting.

Setup tips that paid off

• Mount it solidly. A dedicated stand or heavy bench with through-bolts transforms the user experience.
• Square the blade and table together. A few minutes with a square and a light touch on the clamp alignment gives you cleaner, straighter cuts.
• Prep the clamps. Clean the clamp faces and blades; lightly scuff if you plan to run very fine blades.
• Wax the table. It reduces friction, protects the iron, and helps with tight-radius work.
• Foot switch. A simple deadman-style switch lets you keep both hands on the work while starting/stopping.

Reliability, service, and what I’d watch for

My unit arrived well-aligned and mostly trouble-free, but I’ve seen enough of these in other shops to offer a checklist:

• Check the blower line on day one. If it’s brittle or cracked, replace it immediately.
• Inspect the bevel lock, table scale, and tension lever for play. Minor looseness is easily corrected; anything significant should go back under the 90-day satisfaction guarantee.
• Listen for unusual noise at low speed. Properly tuned, this saw purrs; rattles usually trace to something simple (stand, loose knob, or blower).

The warranty is generous for a tool in this category (3-year limited, 1-year free service, 90-day satisfaction guarantee). Keep your receipt, test thoroughly in the first week, and don’t hesitate to exchange a questionable unit—this saw rewards a good sample with years of smooth service.

Who it’s for

• Ideal: Woodworkers and hobbyists doing fine fretwork, intarsia, templates, and inside-cut work on projects up to 20 inches deep.
• Good fit: Makers who value low vibration, precise control, and quick blade threading over raw power.
• Less ideal: Folks who primarily cut thin metals with very fine blades and demand out-of-the-box perfection. You can get there, but you may want to plan on a clamp upgrade and an arm-lift solution.

Recommendation

I recommend the DW788 for anyone serious about scroll work who wants a smooth, accurate, and quiet saw with a true 20-inch capacity. Its parallel-link design, broad speed range, and front-mounted controls make day-to-day use a pleasure, and the cast-iron table gives it the mass and feel of a shop tool rather than a hobby gadget.

Be aware of its quirks. The bottom clamp is hard to see, the arm doesn’t stay up without detensioning (and benefits from a prop or lift), and the stock blower hose is fragile. If your work leans heavily on ultra-fine blades for metal, plan on a clamp tune-up or an aftermarket set. None of these are deal breakers in my shop; they’re manageable realities of a design that otherwise nails the fundamentals.

In short: for wood-focused scroll work, it’s one of the best balances of price, precision, and user experience available. With a careful setup and a couple of inexpensive tweaks, it becomes a reliably excellent partner for intricate cutting.