A clamping hub comprising a body. The clamping hub further comprising an accessory mount configured to mount an accessory to the clamping hub. The clamping hub also comprising an aperture, within the body, configured to receive a shaft. The clamping hub also comprising a clamp configured to secure the shaft in the aperture.

A fabrication system may generally comprise an x-y positioning assembly, a clamping head to receive an end effector, wherein the clamping head is coupled to the x-y positioning assembly, a z positioning assembly, a platform including a surface that is rigid and substantially planar, wherein the platform is coupled to the z positioning assembly, and a controller operably coupled to the x-y positioning assembly, end effector, z positioning assembly, and platform. Methods of using the fabrication system are also described.

A nut is employed to fix a faucet on a wash basin or a kitchen basin and contains an external driving member and an internal screwing member. The external driving member includes a cylindrical fence, an accommodating cavity, a first edge, and a second edge; the cylindrical fence has at least one limiting block and a griping face. The internal screwing member is fitted into and retained with the accommodating cavity and includes an annular cliff, a through orifice, a third edge, and a fourth edge; the annular cliff has plural slots longitudinally extending and isometrically arranged to the fourth edge from the third edge so as to define a plurality of flexible retaining portions, each having an inner threaded section; the annular cliff also has at least one longitudinal recess for retaining with the at least one limiting block of the external driving member and has a contacting fringe.

In a yoke for a cross shaft universal joint, the forming direction of a through hole (17a) and a screw hole (18a) is inclined relative to the axes of circular holes (19a, 19a) formed in a pair of engaging arm parts (12, 12). And, by fastening a bolt (32) to thereby put first and second flange parts (14a, 15a) nearer to each other, mutually approaching forces are applied to the connecting arm parts (12, 12) in a direction inclined relative the axes of the circular holes (19a, 19a). Thus, cup bearings (29) incorporated in the circular holes (19a, 19a) are pressed against the end of a shaft part (28a) constituting a cross shaft (27), thereby enabling suppression of occurrence of shaking motion between the bearings incorporated in the circular holes and the end of the shaft part of the cross shaft supported rotatably by the bearings.