Popular Woodworking 2006-08 № 156, страница 26

Power-tool Joinery

round file or a coping saw. A simple but effective trick is to drill oversize clearance holes, rather than trying to create oblong ones, and use washers under the screw heads.

The Sliding Dovetail Solution

Using a sliding dovetail to join a batten mechanically to a tabletop is more work, but it's stronger. Cutting the joint isn't difficult, but some patience is required to get a proper fit between your piece s. It's a router operation. Cut the slot by guiding the router along a fence clamped to the tabletop. Form the tail on the batten on the router table.

Most any dovetail bit will do the job, but the particular bit you choose impacts some details of the operation. A dovetail cut must be done full depth in one pass (of course!). In this application, the cut doesn't need to be more than ⁵/l6" deep. The bottom of the cut should be just about as wide as the batten. Of course you'll use the same router bit to cut both the slot and the tail.

If you use a commonplace V^'-M⁰ bit, it's prudent to first rough out the slot with a straight bit in your router. To match the slot to the batten thickness, you'll need to make two passes with the dovetail bit. A larger-diameter bit has more substance at the waist, and you should have no problem hogging out the slot in a single pass.

Test the Tail's Fit

Cutting the tail follows. The first adjustment is bit height. You want a snug fit, with the shoulders of the tail tight against the tabletop surface, so you don't want the bit too high. The next adjustment is the fence position. Use the tweaks I described in the April 2004 issue of Popular Woodworking (#140). I make test cuts on scraps of the batten stock, and fit the resulting tail to the slot.

Remember that it isn't simply a matter of fitting the test block into the slot. It has to pass completely through the slot, from one end to the other. Invariably, I find tight spots - often two or three - where a block that's otherwise sliding satisfactorily binds. The test block isn't impeded by the friction buildup that will drag on the batten itself. So you must use your judgment.

You can try easing the tight spots with sandpaper. Or, feed your test block through the slot several times, abrading and easing the

The dovetail slot must be cut with the bit set to final depth. Clamp scrap to each edge of the tabletop to prevent tearing out the top's edges. Make sure your guide is straight and rigid, perpendicular to the tabletop edges, and securely clamped.

As you set up your router table for cutting the tails on the battens, fit the test block to the slots. When you have a test block that fits the slot, slide it all the way through to ensure you won't have an unpleasant surprise during final assembly of the actual batten.

The dovetail slot for a batten doesn't need to be more than V4" to ⁵/i6" deep. You can rout that in a single pass with a ³/4" to 1" 14° bit on a V2" shank. If you use a smaller dovetail bit, its waist will be weaker; then it's advisable to first rough out the groove with a straight bit.

tight spots. Or tweak the setup, cut a new tail, and run it through the slot. (Which might convince you that the previous setup was the better one, so be sure you can return to it.)

Ultimately, you are going to have to cut a tail on the batten itself and feed it into the slot. The batten isn't glued in place. I copied a

Cut the tail on each batten only after you are satisfied that you have the right fit. Slide it along the fence and cut into one face, then turn it around and cut the second face, completing the tail. You can make an angled sanding block to remove any high spots on the tail.

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Popular Woodworking August 2006