Quick, clean rabbets on the tablesaw
House your dado blade in an auxiliary fence, and cut multiple-width rabbets without changing the blade.
Cutting rabbets in one pass
Tried of the trial-and-error method of shimming your dado blade to produce a rabbet of the needed width, and then repeating the whole process again for a different width rabbet? Here's a simple, no-shim method for cutting rabbets from 1/8" to 3/4" wide in one pass.
Install a 3/4" dado blade in your tablesaw, and position the rip fence 1/8" from the blade. Lower the blade beneath the saw table.
Attach a 3/4"-thick auxiliary fence to the rip fence. (We prefer medium-density fiberboard, but any flat stock will do.) Mark a line on the auxiliary fence 1/16" higher than the depth of the rabbet to be cut.
With the saw running, slowly raise the dado blade, cutting to the marked line. Lower the blade slightly, and turn off the saw.
Note: Cutting into the auxiliary fence 1/16" deeper than needed and then lowering the blade to cut the rabbet keeps the blade from dragging on the fence during the cut.
Adjust the fence position and blade height, making test cuts to arrive at the desired rabbet width and depth. Then rabbet your workpiece.
Keep the auxiliary fence handy for future use. When you need to cut a deeper rabbet, simply reposition the tablesaw fence, as in Step 1; attach the auxiliary fence, as in Step 2; and mark the new rabbet depth. Then cut to the new line, as in Step 3. To avoid having a large opening in the auxiliary fence when cutting a shallow rabbet, make several auxiliary fences so each one covers a different range of depths.