Automatic polishing process of plastic injection molds on a 5-axis milling center

The plastic injection mold manufacturing process includes polishing operations when surface roughness is critical or mirror effect is required to produce transparent parts. This polishing operation is mainly carried out manually by skilled workers of subcontractor companies. In this paper, we propose an automatic polishing technique on a 5-axis milling center in order to use the same means of production from machining to polishing and reduce the costs. We develop special algorithms to compute 5-axis cutter locations on free-form cavities in order to imitate the skills of the workers. These are based on both filling curves and trochoidal curves. The polishing force is ensured by the compliance of the passive tool itself and set-up by calibration between displacement and force based on a force sensor. The compliance of the tool helps to avoid kinematical error effects on the part during 5-axis tool movements. The effectiveness of the method in terms of the surface roughness quality and the simplicity of implementation is shown through experiments on a 5-axis machining center with a rotary and tilt table

Experimental investigation of cutting forces in high-feed milling of titanium alloy

Titanium super alloys are often used in the chemical and aerospace industries, especially because of financial savings. resulting primarily from cheaper operation of equipment. Machinability of titanium alloys is more difficult than that of other metals. In addition, the low thermal conductivity causes the alloy to stick to the cuffing edge of the cutting tool, thereby causing it to become dull faster. The article deals with the experimental evaluation of cutting forces and the design of suitable cutting parameters for the machining of the UNS R56260 titanium alloy with high-feed milling technology. Testing was carried out in climb and conventional milling under different cutting conditions. The cutting components of forces Fx, Fy, Fz were measured and evaluated. The results of the measurements were processed into a graphical form and suitable cutting conditions were designed in terms of the acting cutting forces.Web of Science141958

Process Parameters Optimization in Micromilling of Watch Mechanism Features

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Development of an intelligent automated polishing system

In high-value manufacturing sectors, many manufacturing processes are still performed manually, such as polishing operations for small metallic parts. Increasing volume, the need for consistency in quality, and health and safety issues are some of the reasons for industry to search urgently for alternative solutions for manual polishing processes. This article reports the development of an intelligent automated polishing system to achieve consistent surface quality and removal of superficial defects from high-value components, such as those used in aerospace industry. The article reports an innovative method to capture manual polishing processes by skilled operators. The captured polishing parameters are then used to develop and control a robotic polishing system that can adopt various polishing patterns. A brief summary of existing fully and semi-automated polishing systems and their inadequacy for industrial applications are discussed. The need for building automation system based on manual operations are explained and a systematic data capturing process for a specific aerospace-based component is defined. The development of the process capturing device is explained, the data analysis and interpretations are discussed and the migration from manual operation to an automated polishing system is reported. Further detailed information is given in relation with combining data from various sensors and building of an automated system based on learning from manual operations. The research results are also briefly discussed and conclusions are drawn regarding applicability of automated systems for highly skilled manual operations

Defining scanning trajectory for on-machine inspection using a laser-plane scanner

International audienceScan path planning for on-machine inspection in a 5-axis machine tool is still a challenge to measure part geometry in a minimum amount of time with a given scanning quality. Indeed, as the laser-plane scanner takes the place of the cutting tool, the time allocated to measurement must be reduced, but not at detrimental of the quality. In this direction, this paper proposes a method for scan path planning in a 5-axis machine tool with the control of scanning overlap. This method is an adaptation of a method dedicated to a robot that has proved its efficiency for part inspection

Engineering Design and Prototype Fabrication of HOM Couplers for HL-LHC Crab Cavities

The High-Luminosity upgrade for the LHC relies on a set of RF Crab Cavities for reaching its goals. Two parallel concepts, the Double Quarter Wave (DQW) and the RF Dipole (RFD), are going through a comprehensive design process along with preparation of fabrication in view of extensive tests with beam in SPS. High Order Modes (HOM) couplers are critical in providing damping in RF cavities for operation in accelerators. HOM prototyping and fabrication have recently started at CERN. In this paper, an overview of the final shape is provided along with an insight in the mechanical and thermal analyses performed to validate the design of these critical components. Emphasis is also given to test campaigns, material selection, prototyping and initial fabrication that are aimed at fulfilling the highly demanding tolerances of the couplers