Building A Workbench Base
The base of this joiner's bench is made of standard dimensional lumber. You should be able to buy most of the materials at a local lumberyard.
The base is assembled with truss rods. Truss-rod joints are easy to make and very strong. The bench legs are flush with the front edge of the bench top. This gives the bench a wide footprint for stability, and it makes it possible to use the legs as board jacks to support long boards in the front vise.
You can adapt the bench for specific needs by varying the size of the bench top. Any size top from 24 x 48" to 24 x 72" can be used. The same base dimensions can be used for any top that falls within this size range (Illus. 3-4). The base is made from dimensional lumber. Use 4 X 4-inch fir for the legs and 2 X 4-inch fir for the stretchers. Cut the parts to length, and then cut the joints in the legs. Next, cut the grooves in the stretchers for the truss rods. Use a router (Illus. 3-17) or a table saw with a dado blade to make this groove. The groove can also be made with a plow plane. Sand the legs and stretchers and round the edges slightly. After you have drilled all the countersinking holes, drill the 1/2" holes completely through the legs. Next, drill the dowel holes. The dowels keep the parts in alignment as you assemble the base and keep the stretchers from twisting later. The truss rods hold the joints together and provide most of the strength.
Use a dowelling jig to drill two 3/8" diameter dowel holes in the ends of all the stretchers (Illus. 3-21). Next, lay out the position of the dowel holes in the legs. You can measure their locations or use dowel centers to locate them. Dowel centers are metal plugs that fit in the dowel holes in the stretchers. They have a sharp spur in the center that will make the center of the hole on the leg. Temporarily assemble each joint with the dowel centers in place. Then disassemble the joint and drill the hole using the mark from the dowel center as the center mark of the hole.
You can round over the corners of the legs, if you like. Use an edge-rounding bit in the router (Illus.3-24). The bit I used has a pilot that guides the cut, so there is no need to use a router fence.
Next, cut the truss rods to the approximate lengths. The truss rods are made from 3/8" threaded rod. You will have to buy four 6-foot-long pieces. You will be able to get one long truss rod and one short truss rod from each 6-foot length. After cutting the rod, you will have to file the threads at the cut end before you can attach a nut.
Now, assemble the base. Don't use any glue on the joints. That way, you can disassemble the base later if you need to move it. The truss rods will provide plenty of strength without glue. Insert the 3/8" dowels into the dowel holes in the stretchers.
Attach the end stretchers first. Place the truss rods in their grooves and assemble the joints (Illus. 3-25). Install washers and thread on the nuts (Illus3-26).
Tighten the nuts with a socket wrench (Illus 3-27).
After all the end stretchers are attached to the legs, install the front and rear stretchers (Illus 3-28). When all of the nuts are tight, use a hacksaw to trim off the excess threaded rod.
