Routers, used for a number of tasks in woodworking, utilise a high-speed motor installed in either a fixed--or stationary--base or a plunge base. The plunge base allows the spinning router bit to be plunged directly downward into the wood, then locked into position to complete a cut. Using the locking mechanism, a plunge base router can be used for some tasks typically requiring a fixed base, such as in a router table.
Disconnect the router from the power source. Position the router upside down on a work table.
Install the bit to be used into the router collet. Tighten with the collet wrenches that accompany the router.
Loosen the locking mechanism on the plunge base. Push slowly downward on the spring-loaded plunge base until the bit extends out from the base the desired distance.
Lock the plunge base locking mechanism in place. Verify the desired depth of cut by measuring with a tape measure from the bottom of the router base to the tip of the exposed router bit.
Install the router into your router table or begin routing by hand with the plunge base locked as desired.
When using a router, always wear appropriate safety equipment, including safety glasses and hearing protection.