Tool review: 3-HP Tablesaws
Riving Knife Saws
According to the old joke, every tablesaw made in the last 50 years came with a free dust collector: the combination blade guard/splitter that sits on a shelf collecting dust. That's because most of us reason that we're smart enough not to stick our fingers into a moving blade. However, kickback can surprise even the most seasoned woodworkers, and many tablesaw injuries caused by kickback could have been thwarted by a riving knife, a steel fin located immediately behind the blade that goes up and down with it and prevents a board from contacting the teeth at the back of the blade.
Our test of today's riving-knife-equipped cabinet-style saws reveals that you'll be glad to have most of them in your shop. As we discovered, it's the subtle differences and helpful features that separate the top performers from the pack.
You'll like a riving knife
We're all familiar with the traditional tablesaw splitter, with blade guard and antikickback pawls attached, that's been standard equipment for decades. Mounted to the trunnion assembly at the back of the saw, it tilts with the blade, but does not move up and down. A riving knife, as defined by UL, differs from a splitter in that it mounts immediately behind the blade, moves up and down with the blade, and stands no taller than the top arc of the blade.
This allows you to remove the guard and pawls yet keep this safety device in place to make non-through cuts such as tenons and rabbets. Although a riving knife won't protect your hands from contacting the blade, it greatly reduces the chance of kickback. Of the nine saws we tested, six come with a separate riving knife that swaps with the blade guard/splitter assembly [Photo A]. Many of those require removing the throat insert to access the mechanism that releases the guard or riving knife [Photo B].
Delta's system is unique. Instead of trading the splitter/guard for the knife, the guard and pawls come off the splitter without tools [Photo C], which then drops down to below the blade arc to make it a true riving knife.
As they come from the factory, two saws don't meet UL's definition of a riving-knife saw. Both manufacturers offer riving knives as optional equipment ($30-$40), but, in our opinion, one should be included as standard gear.
All pack plenty of power
Equipped with identical, sharp, 40-tooth blades, these 220-volt, 3-hp saws cut through all thick hardwoods at a hand-fed rate with no trouble. Even when we hooked up a power feeder to provide constant feed rates, only one stalled -- and that wasn't until ripping 3"-thick red oak at a faster-than-we'd-feed-it-by-hand rate of 13 feet per minute (fpm).
All nine saws come standard with T-square-style rip fences that work about equally well. Whether covered with sideboards made of laminate-covered plywood, high-density plastic, or aluminum, they all proved smooth and straight. None have built-in T-track slots for mounting jigs or accessories.
All of the fences lock on the front rails only, so we measured deflection at the back end with a dial indicator while applying sideways force with hanging weights, and also by ripping different sizes of wood and plywood. Seven of the nine demonstrated such minuscule deflection, it would never be noticed. The other two showed a bit of blade scoring.
Some miter gauges stand out
Here we saw real differences. A couple saws come with old-school, ho-hum miter gauges with three miter stops and no frills. Four others add width adjusters on the bars to remedy a sloppy fit in the miter slot. The remaining saws include upgraded miter gauges with extra detent stops, additional adjustments, and large, comfortable handles.
•Cut quality. An expensive saw won't make a bad blade cut better, so it makes sense to outfit the saw with a high-quality blade. Four machines come with a blade, but only one made furniture-quality cuts in our tests. When we outfitted the others with a new, premium blade, we saw improvement with each one.
•Dust collection. These saws fall into three categories for gathering dust: those with only a dust port at the bottom of the cabinet; those with a blade shroud that connects directly to the dust port; and those with a blade shroud and a blade-guard mounted dust port. Generally, saws with blade shrouds outperformed those without; guard-mounted ports proved a mixed bag.
If we had to write the check...
Because of the wide price range with these tablesaws, from $1,350 to $3,300, your budget might be the primary factor in choosing one. If you can afford them, the feature-packed SawStop Professional and Delta Unisaw rise above the field and share Top Tool honors. The SawStop has the exclusive safety blade-brake -- a huge advantage over the field -- a rip fence that did not deflect at all, an easy-to-use-and-change blade guard and riving knife, a built-in mobile base, and the best dust collection.
On the other hand, Delta's made-in-the-U.S. Unisaw has our favorite blade guard and riving-knife system, a stellar miter gauge, and the largest crosscut capacity in front of the blade. The big top combines with a massive trunnion to make it the heaviest saw in the test. The Unisaw also has the best standard-issue blade, a storage drawer below the extension table, and the most routinely used controls—blade height and bevel, riving-knife release, and a large dial bevel gauge -- all on the front of the cabinet for easy access.
If these saws prove out of your price range, then consider the Grizzly G0691, our Top Value at $1,350. With plenty of power and an easy-to-use riving knife, this Grizz gives you a lot for the money.
Learn the results of our testing of the Delta Unisaw 36-L352, General 650R-T50, General International 50-300 M1, Grizzly G0651 and G0691, Jet JTAS-1-XL50-1PK, Laguna Platinum MTS0300-0180, Powermatic PM2000, and SawStop Professional in the May 2010 issue of WOOD magazine.