A router is a rotary tool that has the ability to spin at 35,000 RPM (revolutions per minute) or faster to rotate a cutting blade that shapes, removes, or defines a piece of wood. Routers come in a few different varieties that are for specific uses.
A plunge router gets its name for its ability to drop the cutting head into place giving you the ability to to use this router on an edge or in the middle of the material you are detailing. Because the plunge router has this unique ability to drop down into the material like a drill and cut simply by moving the router in the desired line, there are apparatuses that you can attach to the router that will aid in keeping the router stable. These mechanisms look like arms that allow you to set edge parameters limiting how close the router gets to the edge of the material you are working with.
The plunge router depth is adjusted by a gauge on the side of the router, usually spanning about 1 1/2 inches up and down in 1/16 of an inch increments.
Typical uses for a plunge router are:
Cutting large holes
Fixed Base Router
A fixed base router is a router where the base of the router stays fixed while the material is being cut. The router depth can be adjusted, but very minimally (an inch or so). Fixed base routers are extremely accurate cutting machines and are designed for creating decorative edge details and making complicated carpentry, such as dovetail drawers. In these instances, the fixed base router is often mounted to a router table, allowing the user to use both hands to manipulate the material being worked with.
Typical uses of a fixed base router include:
Creating custom moldings
Routers are one of the most versatile tools for wood working. Having the ability to create your own profiles will make you feel like a professional word worker and give your creations some real depth.