Abstract: Router jig apparatus includes a base portion, a router positioning portion, a workpiece orbiting portion and a workpiece positioning portion. The base portion includes a quadrangular frame section disposed generally horizontally and a supporting stand extending downwardly from the frame section. The router positioning portion includes a plate section slidably engageable with the frame section, the plate section includes a central first opening of a shape to pass a motor of an inverted router and retain a work surface surrounding a bit thereof. The workpiece orbiting portion includes a guide section disposed above and closely adjacent to the frame section, the guide section including a large circular second opening therein. A disc member is rotatably positioned within the guide section opening, generally in a common plane therewith, the disc member including a central third opening.

Abstract: A cutting machine to form a tenon at each end of a piece of timber, which tenon has opposite faces which are inclined both longitudinally and transversely relative to the piece of timber and forming hereinafter called skew tenon faces. This tenon cutting machine is of simple construction and uses a single and simple cutting head to produce both skew tenon faces at each end of a piece of timber.