Popular Woodworking 2002-10 № 130, страница 69
The secret to cleaning out the bottom of your mortise is to go back over your work once you've cut the shape of the entire mortise. I repeatedly raise and lower the head of the mortiser about V211 while moving the workpiece in small increments side-to-side. plunge cut, then move your work (or your sliding table) so that you skip a space that's nearly equal to the width of the chisel. Then make another plunge. Now go back and clean up the waste between the holes. If you made one hole right after another, the chisel will tend to bend toward one side. After a certain amount of stress, your tooling will break. After you've completed a mortise, you want to go back and clean up the gunk at the bottom. See the photo above that shows the fastest way to do this. Sharpening Your Tooling Dull tooling is another source of woe. A simple auger bit file (available from Highland Hardware, 800-241-6748) is the best tool to touch up the auger bit. Always remove as little metal as possible and try to keep the cutting angles the same. To sharpen the chisel, you can use a conical sharpening stone. Touch up the inside four edges and then remove the resulting burr on the outside with one pass on a fine-grit sharpening stone. Again, remove as little metal as possible to avoid changing the width of your chisel. PW jpui v _ Cutting lip —' A Sharpen across the entire face of the spur, maintaining the same angle. Sharpen the underside of the cutting lip, not the top. Cutting lip PW Recommends OCCASIONAL USER The occasional user can get by with an inexpensive mortising attachment to a drill press, chain drilling or using a router to cut mortises. SERIOUS HOME WOODWORKER • Bridgewood HM-11. Low on frills, but its motor grinds through anything ($230). • Grizzly G3183. Virtually the same as the Bridgewood, the G3183 is inexpensive ($225) and powerful. • Shop Fox W1671. This machine has the capacity of a floor-model mortiser. It's hard to beat at $245. ADVANCED WOODWORKER OR PROFESSIONAL • Multico PM-12. The top-of-the-line benchtop machine at $450. The holddown is the best of all the benchtops and the motor is gutsy. • Powermatic 719A. This floor-model mortiser ($800) has sliding tables and a front-mounted clamp to hold your work securely. We use this machine in our shop, and it's now a common sight in small professional shops. Cut one hole, skip a space, then cut another. If you cut one right next to the other, you are heading for a bad bend or break in the chisel or auger bit. When you sharpen the cutting spur of your auger bit, try not to touch the cutting lip (above).When you sharpen the cutting lip, stroke the file upwards into the bit and try not to change the cutting angle. These tools have been tested or used by the editors of Popular Woodworking and have earned their recommendation. 69 |
