A new technique for making cube corner elements that involves end milling is used in the fabrication of cube corner elements having non-orthogonal dihedral angles and dihedral angle errors, and arrays of such cube corner elements. A given optical face of a cube corner element may be a compound face with two constituent faces. In some cases, the constituent faces may be parallel and coplanar such that a given dihedral angle error pertains to the entire optical face, while in other cases, the two constituent faces may not be parallel, and may be associated with different dihedral angle errors.

The present disclosure relates to end milling methods for making microstructures, and articles containing such microstructures. The end milling process comprises rotating an end mill (1410r) around an axis of rotation (1409) and translating the rotating end mill (1410r) in a working surface (1407) to form a first recess (1420) such that end mill (1410r) moves along an inclined path (1411) relative to the working surface (1409), or to a reference plane along which the working surface (1407) extends. The method forms flat faces (1441a, 1441b) that meet along a rounded edge (1451), the edge (1451) being inclined to the reference plane. Both truncated cube corner elements (see for instance FIGS. 47 and 48) and full cube corner elements (see for instance FIG. 56A) can be made in a substrate (4705, 4805, 5605) by forming at least part of an optical face of the cube corner element (4780, 4880, 5680) by cutting the substrate (4705, 4805, 5605) with a rotating end mill (1410r).

The present disclosure relates to end milling methods for making microstructures, and articles containing such microstructures. The end milling process comprises rotating an end mill (1410r) around an axis of rotation (1409) and translating the rotating end mill (1410r) in a working surface (1407) to form a first recess (1420) such that end mill (1410r) moves along an inclined path (1411) relative to the working surface (1409), or to a reference plane along which the working surface (1407) extends. The method forms flat faces (1441a, 1441b) that meet along a rounded edge (1451), the edge (1451) being inclined to the reference plane. Both truncated cube corner elements (see for instance FIGS. 47 and 48) and full cube corner elements (see for instance FIG. 56A) can be made in a substrate (4705, 4805, 5605) by forming at least part of an optical face of the cube corner element (4780, 4880, 5680) by cutting the substrate (4705, 4805, 5605) with a rotating end mill (1410r).

The described embodiments relate to embedding a threaded insert into a thin-walled housing. A recess can be formed with a machining tool that forms a recess in a thickened portion of the thin-walled housing. In some embodiments, the recess can be formed along one of the walls of the thin-walled housing in a location having highly a constrained amount of space available. Once the recess is formed a threaded insert can be pressed into the recess. An interference fit can be utilized to lodge the press-nut securely within the recess. Alternatively, a retaining member can be positioned across a front portion of the recess to trap the threaded insert between the retaining member and a rear surface of the recess.

A portable and field-adjustable milling machine comprises: a base; a milling assembly coupled to the base and that includes a milling tool rotatable by a driver; a roller bed coupled to the base and configured to support a tubular member thereon; and a vice assembly that is coupled to the base. Each vice member of the vice assembly is configured to be moved towards the other of the pair and includes camming surfaces configured to lift the tubular member off of the roller bed in response to the vice members being moved toward one another. The vice member may have a v-shaped notch defined by a pair of angled surfaces. The vice assembly lifts the tubular member and retains it in the notch at a position that is a predetermined distance away from the roller bed.

A portable and field-adjustable milling machine comprises: a base; a milling assembly coupled to the base and that includes a milling tool rotatable by a driver; a roller bed coupled to the base and configured to support a tubular member thereon; and a vice assembly that is coupled to the base. Each vice member of the vice assembly is configured to be moved towards the other of the pair and includes camming surfaces configured to lift the tubular member off of the roller bed in response to the vice members being moved toward one another. The vice member may have a v-shaped notch defined by a pair of angled surfaces. The vice assembly lifts the tubular member and retains it in the notch at a position that is a predetermined distance away from the roller bed.

Tools and methods are provided for scarfing rotor blade segments. A rotor blade segment includes a pressure side and a suction side. A tool includes a first guide configured for mounting on one of the pressure side or the suction side, the first guide including a first curved rail and a second curved rail spaced from the first curved rail. The tool further includes a second guide movably coupled to the first guide at a scarf angle, the second guide including a guide rail extending between and movable along the first curved rail and the second curved rail. The tool further includes a cutting device movably coupled to the second guide, the cutting device movable along the guide rail and operable to remove material from the one of the pressure side or the suction side.

A method for milling a cutout using a milling cutter in a workpiece is provided. A longitudinal axis of the milling cutter is positioned in a first orientation relative to the workpiece to contact a first side of the workpiece. An enveloping cylindrical surface of the milling cutter is then used to cut a cutout which has a plurality of peripheral edges and rounded corners. The milling cutter is then placed in a second orientation which is angled relative to the first orientation. Thereafter, the enveloping cylindrical surface and an enveloping axial surface of the milling cutter are used to further cut the rounded corners of the cutout to form sharp corners.

A skeletonized bolt carrier for an AK rifle is provided. The bolt carrier features a skeletonized operating rod to reduce overall weight while maintaining structural integrity. The bolt carrier also features side indents cut out of both sides of the base block which further reduce weight. The reduced weight of the bolt carrier enables lower gas consumption when firing, resulting in less recoil and less associated muzzle rise, leading to improved accuracy especially when multiple rounds are fired consecutively.

A skeletonized bolt carrier for an AK rifle is provided. The bolt carrier features a skeletonized operating rod to reduce overall weight while maintaining structural integrity. The bolt carrier also features side indents cut out of both sides of the base block which further reduce weight. The reduced weight of the bolt carrier enables lower gas consumption when firing, resulting in less recoil and less associated muzzle rise, leading to improved accuracy especially when multiple rounds are fired consecutively.