Popular Woodworking 2009-10 № 178, страница 21
Levers versus poles. DeWalt's saw uses a spring-loaded lever to adjust the cut height. The other saws in the review have one pole or two poles on which the motor housing travels.
tions on a single pole and the DeWalt uses an entirely different setup on the DW744. The DeWalt unit sandwiches a plate of metal to stay in place, then raises and lowers it using a spring-loaded pivoting arm. Which design is best will be answered in time, but my gut instinct says the two-pole design is better.
The splitter on earlier saws stood above the tabletop to keep a board from pinching the blade and create kickback. But with many of the operations performed at a table saw, the splitter had to be removed - and more often than not, it was never replaced.
A riving knife travels with the blade as it is raised, lowered or tilted. The distance between the blade and knife remains constant, unlike the splitter where the gap increased as the blade was lowered. Also, a riving knife helps keep the wood tight against the fence during the cut.
How the riving knives are adjusted up and down is a major difference with these saws. As with larger saws, most of the riving knife adjustments are accessed through the saw's throat opening. We find the levered
Levers are better. Adjustment of the riving knife begins by unlocking the support, then the knife is positioned appropriately. The Craftsman and Bosch (shown here) saws have a lever instead of a small knob.
designs (on the Bosch, Craftsman and Makita models) better to work with than those with knobs. To reach through the opening is not that easy, but to do so while turning a small knob is asking a lot. Levers that disengage with a simple quarter-turn are the winner in our opinion.
Makita has a much different setup from the other two lever-adjusted saws. Access through the throat is not required. Makita has positioned its lever on the outside of the cabinet, which when pulled, releases the locking plate and allows adjustment of the riving knife. That's cool, but the lever is on the backside of the saw and you'll have to reach over the saw or walk around to the back to gain access.
The DeWalt and Jet saws have knobs, but on the Jet it's so small that a finger and your thumb is all you can use to turn the knob to lock or unlock the knife. And Jet has an issue
with its riving knife design. The opening is a simple slot. There are no notches or extra holes to help secure the knife. The locking plate is the only holding mechanism. Ifyour hand strength is suspect, there's a possibility of the riving knife changing position during a cut.
While the DeWalt saw's three-wing knob is larger, it's still a knob. But once the lock is loose, adjustment of the riving knife is easy and smooth. Simply push in on the knob as you adjust the knife. With pressure off the knob, the catch springs back to secure the knife in place. Then twist the knob to lock it.
The riving knives are left attached and in place or adjusted (slid down into the saw) for non-through cuts. That in turn means that the guards and kickback pawls must be removed for those cuts and replaced when making traditional through cuts. (You can't use the blade guard and pawls when the riving knife is set for a non-through cut.)
In evaluating the guards, you have to look at the design of the guards themselves and the method and ease of attachment. If installation is difficult, the guards are left on a shelf to collect dust.
In our opinion, a good blade guard has a clean line of sight to the blade (you have to be able to see the blade so you know where not to put your hand). The side guards should lock in the up position because on thin cuts you need the guard out of the way. And the side guards should work independent of one another other. Each of the saws meets these requirements except one.
Jet seems to have missed on most of these
Updated designs. The best news for woodworkers using benchtop table saws is the switch from splitters to riving knives. This design is much more user-friendly.
A tale of two knives. See the difference between a riving knife and a great riving knife? The lower knife cannot be removed, only repositioned in the saw while the upper knife displays a series of holes that engage with pins in the knife support. That's extra holding power when the knife is locked.
34 ■ Popular Woodworking October 2009