Popular Woodworking 2003-08 № 135, страница 27
Be mindful of the size of the cut and of the amount of material you will remove in a pass. You don't necessarily want to hog out a 3/8"-deep cut in a single pass, especially if you are using a 11/4"- to 1 ^"-diameter bit. You probably know there are two ways to moderate the bite: Reduce the depth of the cut or the width of the cut. Here, the most expeditious approach is the latter. Form the full cut in small steps. The first pass should be about 1/8" wide, produced by holding the workpiece well clear of the stop, so only 1/8" of the workpiece extends over the bit. Make pass after pass, shifting the workpiece closer and closer to the stop. One last pass with the workpiece dead against the stop and your lap is complete. This approach works well for end-laps, but not for laps midway between the ends of the workpiece. For a cross- or a T-lap, the router table accessory to use is the dadoing sled shown in our April 2003 issue (# 133). You need to use a stop with this sled to keep the work from moving as the bit cuts it, and that helps you place the cut as well. Set the stop to position the final cut, and use a spacer between the stop and the work to position the first cut. Personally, I think it's fussy to do Ts and crosses accurately on the router table. Given my druthers, I'd do them with a hand-held router and a job-specific (and thus disposable) jig, such as the lapping platform shown in the drawing below. Hand-held Router When cutting this joint with a hand-held router, I prefer a fixed-base router, rather than a plunge. I use the same planer-mortising bit, but I mount a pilot bearing on the shank of the bit. The lapping platform I make from four scraps and a dozen drywall screws. I use the actual workpieces to scale it. Begin by clamping the jig's two fences to the edges of a workpiece. These fences need Support platform To assemble a lapping platform, capture a workpiece between the fences and align the primary platform on them.The edge of the platform must be square to the work.You can build the simple version of this jig for cross-laps as shown in the photo or add a work stop as shown in the illustration to also cut end-laps. Main platform Adjustable stop 3V2"
Section, adjustable stop - Carriage bolt Lapping sled www.popwood.com 25 |
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