47 - Build Your Own Mortising Machine , страница 24
FEATURE PROJECT Depth Gauge adjustment (v) block W PLYWOOD) To see at a glance when the mortise is cut to the desired depth, I added a depth gauge to the side of the tower. There's nothing complicated about this gauge. It's just a 6" metal rule attached to a plywood adjustment block (V), see Fig. 16. A long slot in the adjustment block lets you raise and lower the depth gauge. Also, cutting a wide rabbet forms a lip that fits over the edge of the tower, see Fig. 16a. This lip keeps the depth gauge aligned as you move it up and down. ATTACH RULE. The metal rule is attached with two screws. Tightening the screw heads against the rule holds it securely in place. INSTALL GAUGE. Now you can install the gauge. A threaded knob that passes through the adjustment block and into the T-nut (installed earlier) is all that's needed here. INDICATOR. To make it easy to "read" the depth gauge, I added an indicator to the side of the carriage. It's just a nail with the head snipped off. After drilling a hole for the nail, I used epoxy to hold it in place. SETUP. To use the depth gauge, lower the carriage until the tip of the bit touches the workpiece. Then adjust the gauge so the indicator points to the final depth of the mortise. As you lower the carriage to make a series of successive cuts, the indicator will eventually point to the bottom end of the rule. That's when you know the mortise is at the correct depth. Router 3it Guard FRONT FENDER WASHER guard block shield (514 x 7%"-14 PLEXIGLAS) T-NUT GUARD side view DRILL AND 5/is'-x COUNTERSINK KNOB FOR #& x 1" Fh (w/ 1 STUD) WOODSCREW (114" x 7Vz"- 3/„" TWirk" !4 -THICK STOCK) Since the router bit is exposed below the carriage, it's a good idea to add a guard for safety. Note: The guard shown here is made from scrap pieces of material. But if you prefer a single-piece plastic guard like the one shown in the photo on page 16, it's available as part of our complete hardware kit. (See page 31 for Sources.) The guard that's shown in Fig. 17 is quite simple. In fact, there are only two pieces: a plastic shield and a hardwood guard block, see Fig. 17. SHIELD. The shield is just a piece of Plexiglas with a couple of adjustment slots that allow you to raise and lower the guard. Note: You can find Plexiglas at most home centers. GUARD BLOCK. Although the shield extends clown in front of the carriage, I also wanted part of the guard to extend underneath. So I attached the guard block to the bottom edge with screws. MOUNTING. To hold the guard in place, I used a couple of plastic knobs and a pair of fender washers. The knobs are threaded into the T-nuts that were added earlier to the front (K) of the carriage, see Fig. 17a. 24 ShopNotes No. 47 |
