Drill Bits Provide Great Measurements
When setting the distance from a router bit to the fence on your router table, a drill bit often can provide you with a more accurate measurement than any ruler in your shop. For example, when you need a 1⁄4 " space, simply hold the shank of a 1⁄4 " twist-type drill bit against the router bit, as shown at top, and move the fence in until the drill bit fits snugly against both surfaces.
Don't, however, push the fence in so tight that you can't remove the drill bit. Rather, adjust the fence until the drill bit drags lightly on both the router bit and the fence when you withdraw it (much like using a spark-plug feeler gauge).
You also can employ this technique for setting the height of a router bit. Place a straightedge across the top of the bit, as shown at top, and adjust the height of the router bit until the drill bit fits snugly between the router base or tabletop and the straightedge. Doing this will save a lot of adjustment time, too.
—Ed John, South Sioux City, Neb.