Multiple-pass router cuts go quickly
You like to make certain cuts with your table-mounted router in steps. What you don't like is reaching under the table to adjust the router 1⁄16 " or 1⁄8 " after each cut—it sure slows down the job.
Set your router to the final cut depth, and then leave it there. Now, make your depth adjustments by laying several pieces of thin cardboard, artist's mat board, or poster board (all available at art-supply dealers and some crafts shops), or even 1⁄8 " hardboard on the router table. Each piece must be wide enough and extend far enough past the bit on each side to support your workpiece properly. Cut a hole in each piece for the router bit to protrude through, and secure the pieces to the table with double-faced tape. Make your first cut with all of the shims stacked in place. Remove one for each subsequent pass until you've removed them all for the final cut. Each one you remove increases your depth of cut by its thickness.
—Bob Agner, Muskego, Wis.