Abstract: A router guide assembly for cutting quarter circles and annular pieces from a workpiece comprising: a guide frame comprising a first locking means, a first arm and a second arm, the first arm positioned at a right angle to the second arm; a guide bar adjustably connected to the guide frame by the first locking means, wherein the first locking means permits radial reciprocal movement of the guide bar; a radius bar; and means for adjustably and pivotally connecting said radius bar to the guide bar, including a second locking means for adjustably restraining said radius bar, wherein the second locking means permits both sectoral and radial movement of the radius bar; a router stand connected to the radius bar; and a first stop and a second stop attached to the guide bar for limiting the sectoral movement of the radius bar about a pivot point.