The term router planer can be used to describe either of two types of woodworking power tools. Both are used to plane material from timber surfaces either with the view to sizing or to producing square, flat surfaces. The first of these tools is the combination router planer which typically comes as a set consisting of an interchangeable drive motor with several attachments including a router base and a hand planer. The second type consists of a conventional vertical cut router mounted on a set of slides which allow the router to be run in a straight line across a board. When a cut is finished the whole slide arrangement is advanced slightly to position the router for the next run across the board.
A powered woodworking tool, a router planer is used to or shave off thin layers of timber to achieve correct sizing or thicknesses and to produce flat, square surfaces. Similar in operating theory to traditional hand planers, the router planer moves flat across a timber face, thereby maintaining its blade at a constant height to remove a controlled amount of material. These planer variants are typically fairly narrow so, unlike a thicknesser which can process wide boards in a single pass, they have to be advanced across the face of wide pieces of timber in a series of even cuts. When planing the edges of boards or doors however, the router planer can cut the entire surface in a single pass.
There are two types of router planers, the first of which is a combination tool that uses a single, interchangeable motor to drive several attachments. This set typically includes a router base and a planer attachment among others. This configuration allows for both conventional planing and routing operations to be carried out by simply changing attachments. Although not strictly a single tool as such, these combinations are commonly classified as router planers.
The second type of router planer is a little more complex and consists of a set of guide rods with a sliding base or sled as it is normally known. Mounted on the sled is a conventional vertical router equipped with a fairly broad bit. This arrangement is placed over the timber workpiece in such a way that the router moves in a straight line down its length. The sled and guides are attached to a base that features a manual lead screw type adjustment which moves the entire guide and sled arrangement across the board's breadth in a controlled manner.
To use this type of router planer, the router is started and lowered onto the board face. Once it starts cutting, it is moved along the length of the board to remove a thin layer of timber. When the cut is completed, the lead screw is turned, and the sled and guides moved up to a position which places the router bit adjacent to and just overlapping the last cut. The sled is then pushed across the length of the board again to make the next cut; this sequence is repeated until the entire board surface has been processed. The depth to which the router cuts is adjustable, thereby allowing for very fine control of the amount of material removed with each pass. This type of planer is generally better suited to cut the flat faces of boards rather than edge work.