Abstract: A router jig can be attached to a router base by two parallel guide rods extending from a bridge portion of the jig through openings in the router base. In order for a single router jig to be usable with a wide variety of routers, one must select guide rods having an appropriate diameter and must also provide a means of connecting the guide rods to the router jig bridge at a height and a horizontal spacing characteristic of the router being used. This may be done by using two offset arms, each of which is pivotally attached to the bridge at one end and to an associated guide rod at the other end.

Abstract: A router jig can be attached to a router base by two parallel guide rods extending from a bridge portion of the jig through openings in the router base. In order for a single router jig to be usable with a wide variety of routers, one must select guide rods having an appropriate diameter and must also provide a means of connecting the guide rods to the router jig bridge at a height and a horizontal spacing characteristic of the router being used. This may be done by using two offset arms, each of which is pivotally attached to the bridge at one end and to an associated guide rod at the other end.

Abstract: A marking apparatus provides a method of marking a line on a surface of a workpiece at a selected distance from a datum edge of the surface. To practice this method a scribe retaining apparatus is attached to a ruling blade of a geometrical instrument so that it can slide along an axis of the ruling blade. A stock of the geometrical instrument is then brought into abutting contact with the datum edge and held against it at an angle selected so that a first, flat, portion of a bottom of the scribe retaining apparatus abuts the surface of the workpiece. In this orientation a working tip of a retained scribe is adjacent to, but out of contact with, the surface of the workpiece. One then slides the scribe retaining apparatus axially along the ruling blade until the working tip of the scribe is at the selected distance from the datum edge, and locks the scribe retaining apparatus to the ruling blade.