You may be familiar with the technique for using a hand-held router fixed in a trammel to “spin” a perfectly circular workpiece. It’s a great way to shape round tabletops. Making round workpieces on the router table works similarly, only here the router and bit are stationary while the workpiece rotates.
The key is a barebones jig made up of an auxiliary tabletop, a swing arm, and a stop. All of the pieces can be made from 1⁄4" hardboard. To accommodate the swing arm, I sized the top to overhang the sides and front of the table. After drilling a series of pivot pin holes in the swing arm, it’s attached near the front left corner of the top with a bolt, washers, and nut. To set up, a straight bit is installed in the router table (I like to use a spiral flute up-cut bit) and the auxiliary top is positioned over it and clamped down. Then, after drilling a small centered hole in the rough-shaped workpiece, it’s placed over the pivot pin (a nail) in the swing arm. Finally, you’ll clamp the stop in place to limit the travel of the swing arm and produce the desired diameter.
With everything ready to go, you simply turn on the router and pivot the arm and workpiece toward the bit. When the arm contacts the stop and the bit is engaged, you slowly and steadily rotate the workpiece counterclockwise. After a full turn or more, retract the arm with the trimmed workpiece. You’ll get a smoother end result if you sneak up on the final diameter by trimming the workpiece incrementally. You simply move the stop back a little bit between passes.
