Woodworker's Journal 2008-32-1, страница 37

Bringing it all together

Drilling the Side-Rung Mortises

When the ladders are fully dry. it's time to drill the side-rung mortises. I'll save you the geometry lesson and just say that you can use the same side-run mortising jig (SRMJ) to drill the side-rung mortises in both ladder assemblies.

Take a couple of moments to study the photo, below right. Here the jig is set up to drill side-rung mortises in the front ladder. I simply clamped the jig to my drill press table so that when I brought the bit into the front post, it drilled a mortise along the centerline of that post, exactly 15/16" deep. It may take a bit of experimentation to get this set up correctly, so experiment using a section of scrap turned to the correct diameter. Once everything is dialed in, slide the front ladder along the jig, drilling the three side-rung mortises on that post. Then turn the ladder around and drill the three mortises in the other post.

To drill the side-rung mortises in the back ladder, rotate the jig 180 degrees on the drill press table and clamp it in place to bore mortises along the centerlines of the posts. Again, make these exactly 15/16" deep. Work out the setup on scrap first, (.Editor's note: Be sure to drill the mortises for the tenons at the back of each arm now, while the back ladder is on the SRMJ.)

Assemble the Chair Frame

Once all the side-rung mortises are drilled, dry-fit the chair frame together by placing all of the side-rung tenons into their mortises. If you've got a good fit, pull the assembly apart, brush glue onto the parts and squeeze the front and back ladders together with a clamp. Allow the glue to dry thoroughly.

The author details the crest rail with decorative carvings using a sharp knife and paring chisel, followed by careful sanding.

Chop out the crest rail mortises in the back posts with a 1/4" mortising chisel. Make the mortises 9/16" deep and 17«" long. Use a curved support to brace the post from below and to keep it from twisting.

Making the Arms and Rockers

Make patterns for the arms and rockers (see gridded Drawings, right), and trace them onto your project stock. Saw the rockers and arms to shape. I fair the arms by hand, using a series of pencil marks to set the transi

tion areas for shaping. I rough-in the long-grain bevels with a drawknife. The arms are then finished with chisels, rasps and sandpaper. Now whittle the 7/8"-long, 5/8"-diameter tenons on the ends of the arms, and drill the front post tenon mortises.

After you've glued your front ladder together, set up the side-rung-mortise jig (SRMJ) as shown so that it will bore a 15/16"-deep mortise in the center of the posts. Then drill the three side-rung mortises in one post, turn the ladder around, and drill the three side-rung mortises in the other post. Next, rotate the jig 180 degrees on your drill press table and drill the side-rung mortises in the back ladder.

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February 2008 Woodworker's Journal