Abstract: A method of computer numerical control (CNC) machining and of hybrid manufacturing are set forth. A more precise alignment of a computer-aided design (CAD) workpiece model, workpiece, and a CNC machine tool is furnished via employment of the method. The method has proved particularly useful for preform workpieces fabricated by additive manufacturing. The part outcome can more closely conform to the intended final part geometry. In an implementation, a coordinate system is established in a CNC machine tool, and a workpiece is fixed in the CNC machine tool. The fixed workpiece is scanned, and the coordinate system is located in the scanned image. Further, a computer-aided design (CAD) model of the workpiece is aligned in the scanned image, and the coordinate system is utilized as the work coordinate system, among other possible steps of the method.

Abstract: A Bayesian learning approach for stability boundary and optimal parameter identification in milling without the knowledge of the underlying tool dynamics or material cutting force coefficients. Different axial depth and spindle speed combinations are characterized by a probability of stability which is updated based upon whether the result is stable or unstable. A likelihood function incorporates knowledge of stability behavior. Numerical results show convergence to an analytical stability lobe diagram. An adaptive experimental strategy identifies optimal operating parameters that maximize material removal rate. An efficient and robust learning method to identify the stability lobe diagram and optimal operating parameters with a limited number of tests/data points.

Abstract: A method of forming integral articles having non-line-of-site contours includes the steps of providing a plurality of molds, the molds having at least one mold channel therethrough. The plurality of molds are stacked on one another to form a mold stack, wherein at least one portion of the mold stack provides a non-line of sight multi-level channel through at least partial overlap of the mold channels between adjacent ones of the plurality of molds. A flowable material is applied to the mold stack. The flowable material is pressed to fill the mold channels in each of the plurality of molds to form an integral article comprising a plurality of stacked integrally connected levels of the material, wherein through interconnection of the integrally connected levels the integral article provides at least one non-line of sight contour traversing in its thickness direction. The mold stack is then separated or removed to free the integral article.

Abstract: A method for predicting a tool point response of a spindle-holder-tool assembly to be used for high-speed machining applications is provided. The method includes determining direct and cross displacement-to-force receptances of a standard holder clamped in the spindle. The method also includes determining direct receptances at a free end of the standard holder based upon the determined direct and cross displacement-to-force receptances of the standard holder. Additionally, the method includes performing an inverse receptance coupling to simulate a decomposition of the standard holder into multiple subassemblies, the subassemblies including a spindle-holder base subassembly and an extended holder subassembly. The method further includes determining spindle-holder base subassembly receptances based upon the simulated decomposition of the standard holder.

Abstract: A variable tuned holder for machine tools that attaches to a machine tool to act in a manner similar to a dynamic absorber while the machine tool is used during machining. The natural frequency of the holder may be matched to the natural frequency of the machine tool as the tool is in use to reduce the amplitude of vibration at the cutting end of tool with a workpiece. The present invention is designed to provide an impedance match between the machine tool and the holder such that the cutting energy may escape and/or be dissipated. The flexible holder may be used as one part of an overall system. The system may be designed to be used with tools of different shapes and/or lengths. As the shape and/or length of the machine tool changes, the system may be easily modified to change the natural frequency of the flexible holder to enable the dynamic absorber effect of the flexible holder to occur.

Abstract: A variable tuned holder for machine tools that attaches to a machine tool to act in a manner similar to a dynamic absorber while the machine tool is used during machining. The natural frequency of the holder may be matched to the natural frequency of the machine tool as the tool is in use to reduce the amplitude of vibration at the cutting end of tool with a workpiece. The present invention is designed to provide an impedance match between the machine tool and the holder such that the cutting energy may escape and/or be dissipated. The flexible holder may be used as one part of an overall system. The system may be designed to be used with tools of different shapes and/or lengths. As the shape and/or length of the machine tool changes, the system may be easily modified to change the natural frequency of the flexible holder to enable the dynamic absorber effect of the flexible holder to occur.

Abstract: A method of forming integral articles having non-line-of-site contours includes the steps of providing a plurality of molds, the molds having at least one mold channel therethrough. The plurality of molds are stacked on one another to form a mold stack, wherein at least one portion of the mold stack provides a non-line of sight multi-level channel through at least partial overlap of the mold channels between adjacent ones of the plurality of molds. A flowable material is applied to the mold stack. The flowable material is pressed to fill the mold channels in each of the plurality of molds to form an integral article comprising a plurality of stacked integrally connected levels of the material, wherein through interconnection of the integrally connected levels the integral article provides at least one non-line of sight contour traversing in its thickness direction. The mold stack is then separated or removed to free the integral article.

Abstract: A method for predicting a tool point response of a spindle-holder-tool assembly to be used for high-speed machining applications is provided. The method includes determining direct and cross displacement-to-force receptances of a standard holder clamped in the spindle. The method also includes determining direct receptances at a free end of the standard holder based upon the determined direct and cross displacement-to-force receptances of the standard holder. Additionally, the method includes performing an inverse receptance coupling to simulate a decomposition of the standard holder into multiple subassemblies, the subassemblies including a spindle-holder base subassembly and an extended holder subassembly. The method further includes determining spindle-holder base subassembly receptances based upon the simulated decomposition of the standard holder.

Abstract: Displacement measuring interferometer systems and methods are disclosed. One or more acousto-optic modulators for receiving a laser light beam from a laser light source can be utilized to split the laser light beam into two or more laser light beams, while spatially separating frequencies thereof. One or more reflective mechanisms can be utilized to reflect one or more of the laser light beams back to the acousto-optic modulator. Interference of two or more of the laser light beams generally at the acousto-optic modulator can provide an interfered laser light beam thereof. A detector for receiving the interfered laser light beam can be utilized to provide interferometer measurement data.

Abstract: In milling operations, periodically sensed vibration signals synchronous with tool revolution enables a determination of whether the tool returns to approximately the same position each revolution. If so, stability is indicated by tightly grouped values of the periodically sensed vibration signal. If the tool does not return to the same position, spread in the value of the periodically sampled vibration signals is produced thereby indicating chatter conditions. Variance values may be calculated and displayed; histograms may be produced and displayed; corrective action, if needed, may be taken in response to the variance values and/or histogram. Nominal (or commanded) spindle speed, while not necessarily exactly synchronous with actual tool rotation, is entirely adequate to trigger samples and achieve clear indication of the presence or absence of chatter.