Patent attributes
An apparatus for cutting a precision dado in a board includes a base member. The base member includes an adjustable clamp that surrounds a guide fence and which can move along the length of the fence. The fence is clamped to the board where desired for each dado. The base member includes a central area that is adapted to receive a dado guide bushing which is attached to a router having a router bit. The central area allows limited movement of the bushing and the router bit in the dado guide perpendicular to the fence. This allows the router bit, which is smaller than the width of the dado, to fully cut the dado in two passes. Setup of the dado guide to accommodate the width of a shelf to be inserted in the dado is described as is the precise location of the dado guide with respect to the board.