68 - Our All-New Router Jig, страница 19
FEATURE PROJECT blocks that will be used to hold the router and router plate in place. Before assembling the pieces, you can lay out and cut an arc on each side piece. Once this is done, all you have to do is glue and screw the sides to the front and back. Bottom - The bottom (L) of the carriage is also cut from plywood. It is simply sized to fit the opening in the bottom of the carriage. Before it gets screwed in place, a slot is cut in the center for a carriage bolt that will be used to help secure the carriage to the base of the mortising machine, as shown in Figures 10 and 12. Clamp Blocks - At this point, the basic structure of the carriage is complete. But you still need a way to secure the router plate to the carriage. I did this by making a couple of clamp blocks, as you see in Figures 13 and 13a. The clamp blocks (M) are nothing more than a couple of pieces of plywood that fit against the back of the router plate and the sides of the carriage. I cut the blocks slightly wide to begin with. (I made mine 23/i".) Later, they will get trimmed to final width. As you can see in Figure 13,1 used aluminum splines to align the clamp blocks with the sides of the carriage. A kerf is cut in each block and then an aluminum spline is epoxied in of the sliding table. You can see what I'm talking about in Figure 14a. The drawer slides travel so effortlessly that it can be a little hard to control the movement of the carriage. To create a bit of drag on the carriage, I added a carriage bolt, fender washer, and lock nut to the carriage and base of the machine, as shown in Figure 10a. You can vary the amount of friction by tightening or loosening the lock nut. Lever Arm - Hie only thing left to add in order to complete the carriage is the lever arm assembly. As you can see in the photo on the opposite page, this arm simply provides a convenient way to move the carriage forward and backward. This assembly is made up of two parts — a lever arm (N) and a lever arm block (0). Both of these pieces are cut from blanks that are glued up from two layers of plywood. After the arm is cut to shape, the edges are rounded over on one end to create a comfortable grip for your hand. The lever arm pivots on a short length of steel rod that is epoxied into a hole in the lever arm block. A second rod epoxied into the arm engages the slot on the side of the carriage and moves it forward or backward when the arm is pulled. After the holes are drilled and the rods are epoxied into place, you can simply screw the lever arm block to the base of the machine. place. After this is done, you can trim the width of the blocks so the router plate just fits between the blocks and the front plate of the carriage, as shown in Figure 13a. The last step is to clamp the blocks in place and drill a hole in each one for a T-nut and threaded knob (Figure 13b). Drawer Slides - The carriage is mounted to the base of the mortising machine with a pair of full-extension drawer slides. This allows the carriage to slide smoothly back and forth. The drawer slides are mounted so that they are flush with the front edge of the carriage when the carriage is pushed all the way forward and butted against the edge KNOB, 11/2" LONG CLAMP BLOCK (21/2" X1W) SPLINE (1/s" x %" ALUMINUM, m" LONG) ROUTER PLATE DRILL s/i6" HOLE FOR T-NUT ROUT'/2"-ROUNDOVER ON TOP EDGES OF LEVER ARM LEVER ARM (11/2"x1 T-11/2" ply.) LEVER ARM BLOCK #& x 1'/2" Fh 1/2" STEEL WOODSCREW ROD, 3" LONG DRAWER _SLIDE_j NOTE; BEFORE SCREWING TO BASE, POSITION LEVER ARM BLOCK SO LEVER IS JUST BEHIND STAR KNOB WHEN IN FORWARD POSITION No. 68 ShopNotes 19 |
