25 - Special Table Saw Issue, страница 5
JIGS & ACCESSORIES With the brackets in place, the next step is to screw a butt hinge to the end of each support, see Fig. 1. These hinges allow the knee switch to swing. IRIS Now you're ready to move on to the U-shaped knee bar that's made up of two arms and a bar. To determine the length of the arms (B), just measure from the bottom of the table top to the center of the OFF button, see Fig. 2. Then add Vg" for a dado that's added next. Once the arms are cut to size (I used 3/4"-thick hard maple), a dado is cut on each side of the arm — one allows clearance for the hinge knuckle, the other accepts the bar, see Fig. 2a. When screwing the hinges to the arms, leave a W clearance on top so the arms can swing freely, «ee Fig. 2a. After you've screwed hem in place, all that's left is to add the bar. BAR The bar (C) hangs from the arms and runs across the full width of the table saw. The bar is just a length of lV^'-dia. dowel with a plunger (a V^'-dia. dowel) glued in it to make contact with the OFF button, refer to Fig. 4. To determine the length of your bar (C), measure from the outside edges of the arms and add 8" for a 4" overhang at each end, see Fig. 3a. Then to locate the hole for the plunger (D), temporarily clamp the bar to the arms, see Fig. 3. And make a mark on the bar where it's directly over the OFF button, see Figs. 3 and 3a. Now drill a hole and add the plunger. Finally, to mount the bar, I again clamped it in place with the plunger positioned over the OFF button, then screwed the arms to the bar, see Fig. 4 and 4a. No. 25 ShopNotes mark bar directly on off button center hole on off button plunger (v2"-dia. with off button Hand Operated. The shut-off bar is designed to be knee operated, but you can also use your hand. Many table saws come with toggle-type power switches. If your saw has one, you'll have to replace it with a push-button switch before you can build and use the knee switch, see photo. Push-button switches are available through most electrical supply dealers. Some tool manufacturers even carry them. But check around. We found prices ranging from $30 to $130. Push-Button. To build the knee bar, you'll need a pushbutton switch like this. |
