scholarly journals Generation Method of Cutting Tool Paths for High-Speed and High-Quality Machining of Free-Form Surfaces

2021 ◽  
Vol 15 (4) ◽  
pp. 521-528
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama ◽  
Song Cheol Won ◽  
◽  
Keyword(s):  
High Speed ◽  
Processing Time ◽  
Free Form ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Block Processing ◽  
Tool Paths ◽  
Nc Program ◽  
Straight Line ◽  
Free Form Surfaces

In general, NC programs for machining free-form surfaces using a computer numerical control (CNC) machine tool are generated using a computer-aided manufacturing (CAM) system. The tool paths (CL data) generated by a CAM system are approximated straight-line segments based on tolerance (allowable error). As a result, the tolerance affects the machining accuracy and time. If the tolerance is set to a small value, the lengths of the segments are shortened, and the machining accuracy is improved. The process in which a CNC machine tool reads and analyzes an NC program and controls the motors requires a minimum processing time of an NC program block (block-processing time). Therefore, if the lengths of the approximated straight-line segments are too small, it will be impossible to reach the indicated feed speed, and the machining time will be longer. In this study, by identifying the block-processing time of a CNC controller and deriving the appropriate length of the approximated straight-line segment based on the block-processing time, a CL data creation method that is capable of high-speed and high-accuracy free-form surface machining is proposed. In addition, experimental verification tests of the method are conducted.

Tool Path Generation Method for High-Quality Machining of Free-Form Surfaces

2020 ◽  
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama
Keyword(s):  
Tool Path ◽  
High Accuracy ◽  
Tool Path Generation ◽  
Free Form ◽  
Machining Accuracy ◽  
Path Generation ◽  
High Quality ◽  
Nc Program ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract Machining data (NC program) is generated by a CAM system, which generates the tool path from the target shape as a plane approximation surface instead of a free-form surface. Owing to this plane approximation, machining accuracy is reduced. In this paper, we propose a method to process the shape with high accuracy by defining the areas where accuracy is not required as a plane approximation surface and defining the part where accuracy is required as free-form surfaces.

Adaptive Tool Path Planning Strategy for 5-Axis CNC Machining of Free Form Surfaces

2019 ◽  
Author(s):  
Hrishikesh Mane ◽  
S. S. Pande
Keyword(s):  
Tool Path ◽  
Cnc Machining ◽  
Memory Storage ◽  
Free Form ◽  
Cnc Machine ◽  
Planning Strategy ◽  
Part Quality ◽  
Tool Paths ◽  
Path Topology ◽  
Free Form Surfaces

Abstract This paper presents a curvature based adaptive iso-parametric strategy for the efficient machining of free form surfaces on 5-axis CNC machine using the flat end mill tool. One iso-parametric boundary of the surface is selected as the initial tool path. Set of cutter contact (CC) points are chosen adaptively on the initial tool path considering desired profile tolerance. Adjacent iso-parametric tool paths are computed adaptively based on the scallop height constraint unlike the traditional iso-parametric approach. The path topology is post-processed to generate the part program for 5-axis CNC machine in ISO format. The system was rigorously tested for various case studies by comparing the results with the traditional 5-axis iso-parametric tool path strategy, iso-scallop strategy and iso-planar strategy of a commercial software. Our system was found to generate efficient tool paths in terms of part quality, productivity and memory storage compared to the conventional strategies.

Spiral Tool Path Planning Using Eccentric Parameters

2014 ◽  
Author(s):  
Baosu Guo ◽  
Qingjin Peng ◽  
Xiaosheng Cheng ◽  
Ning Dai
Keyword(s):  
High Speed ◽  
Tool Path ◽  
Free Form ◽  
Tool Path Planning ◽  
Inverse Mapping ◽  
Machined Surface ◽  
Tool Paths ◽  
Spiral Tool Path ◽  
Free Form Surfaces ◽  
The Relationship

Free-form surfaces can be machined continuously with minimum tool retractions and at the high speed by following a spiral tool path. This paper presents an improved planning method of the spiral tool path using eccentric parameters for machining free-form surfaces. The relationship between a 3D machined surface and the 2D circular region is established through the conformal mapping. In order to generate an even path, eccentric parameters are used in 2D parametric circular regions to optimize the path interval. The proposed method produces planar spiral segments as a diagonal curve between every two adjacent parametric tool paths. A 2D spiral tool path is gained by linking spiral segments in sequence. Inverse mapping of the 2D spiral tool path onto the machined surface generates the 3D spiral tool path. The main processes of the proposed method include reducing dimensions of free-form surfaces, calculating the eccentric parametric tool path, and generating the planar diagonal spiral tool path. Some applications are used to verify the proposed methods. The proposed method allows the start point to be arbitrary and generates more even tool paths than the existing methods by introducing the mapping distortion.

Integrated Kinematic Machining Error Compensation for Impeller Rough Tool Paths Programming in a Step-Nc Format Using Neural Network Approach Prediction

2021 ◽  
pp. 144-170
Author(s):  
Hacene Ameddah
Keyword(s):  
Neural Network ◽  
Research Work ◽  
Free Form ◽  
Cnc Machine ◽  
Rough Machining ◽  
Neural Network Approach ◽  
Tool Paths ◽  
Nc Program ◽  
Finishing Process ◽  
G Code

The most important components used in aerospace, ships, and automobiles are designed with free form surfaces. An impeller is one of the most important components that are difficult to machine because of its twisted blades. This research book is based on the premise that a STEP-NC program can document “generic” manufacturing information for an impeller. This way, a STEP-NC program can be made machine-independent and has an advantage over the conventional G-code-based NC program that is always generated for a specific CNC machine. Rough machining is recognized as the most crucial procedure influencing machining efficiency and is critical for the finishing process. The research work reported in this chapter focuses on introduces a fully STEP-compliant CNC by putting forward an interpolation algorithm for non uniform rational basic spline (NURBS) curve system for rough milling tool paths with an aim to solve the problems of kinematic errors solutions in five axis machine by neural network implementation.

scholarly journals Design and Evaluation of Uniform LED Illumination Based on Double Linear Fresnel Lenses

2020 ◽  
Vol 10 (9) ◽  
pp. 3257
Author(s):  
Hoang Vu ◽  
Ngoc Minh Kieu ◽  
Do Thi Gam ◽  
Seoyong Shin ◽  
Tran Quoc Tien ◽  
...  
Keyword(s):  
High Speed ◽  
Field Experiments ◽  
Numerical Control ◽  
Free Form ◽  
Light Sources ◽  
Cnc Machine ◽  
Led Lighting ◽  
Positive Effects ◽  
Fresnel Lenses ◽  
Linear Fresnel Lenses

Redistribution of LED radiation in lighting is necessary in many applications. In this article, we propose a new optical component design for LED lighting to achieve a higher performance. The design consists of a commercial collimator and two linear Fresnel lenses. The LED radiation is collimated by a collimator and redistributed by double linear Fresnel lenses to create a square-shaped, uniform distribution. The linear Fresnel lenses design is based on Snell’s law and the “edge-ray principle”. The optical devices are made from poly methyl methacrylate (PMMA) using a high-speed computer numerical control (CNC) machine. The LED prototypes with complementary optics were measured, and the optical intensity distribution was evaluated. The numerical results showed we obtained a free-form lens that produced an illumination uniformity of 78% with an efficiency of 77%. We used the developed LED light sources for field experiments in agricultural lighting. The figures of these tests showed positive effects with control flowering criteria and advantages of harvested products in comparison with the conventional LED sources. This allows our approach in this paper to be considered as an alternative candidate for highly efficient and energy-saving LED lighting applications.

Computing Cutter Engagement Values in Milling Tessellated Free-Form Surfaces

2010 ◽  
Vol 10 (4) ◽  
Author(s):  
Zhiyang Yao ◽  
Ajay Joneja
Keyword(s):  
Computational Model ◽  
Cutting Force ◽  
High Speed ◽  
Tool Path ◽  
Free Form ◽  
High Speed Milling ◽  
Free Form Surfaces ◽  
Potential Use ◽  
Do So

High speed milling (HSM) has great potential use in die/mold cutting, but traditional machining plans do exploit HSM capabilities effectively. An important consideration in HSM is to limit cutting force variations, and one way to do so is to reduce cutter-workpiece engagement (CWE) variations. CWE is measured as the area of the tool instantaneously engaged with the part. Estimating CWE as a function of the tool path requires repeated, expensive computations. This paper develops algorithms for a discretized computational model to make CWE computations for arbitrary shaped parts.

Theoretical Research on Polishing Free-Form Surface with Magnetic Abrasive Finishing

2008 ◽  
Vol 392-394 ◽  
pp. 404-408 ◽  
Author(s):  
Man Dong Zhang ◽  
Ming Lv ◽  
H.L. Chen
Keyword(s):  
Design Theory ◽  
Theoretical Research ◽  
Free Form ◽  
Machining Accuracy ◽  
Magnetic Pole ◽  
Computer Aided Geometric Design ◽  
Magnetic Abrasive Finishing ◽  
Abrasive Finishing ◽  
Free Form Surface ◽  
Free Form Surfaces

In the paper, polishing free-form surfaces of die are studied with magnetic abrasive finishing. The principle of magnetic abrasive finishing free-form surface, the design of magnetic pole, the composition and categories of magnetic abrasive are introduced. Through digitizing of free-form surface by using trimmed NURBS, based on residual roughness, machining accuracy and other parameters, the offset variable of free-form surface, which is the path of magnetic pole, is derived with the computer aided geometric design theory. These will provide theoretic foundation for the realization of finishing free-form surfaces of die automatically.

Development of a Smart Computer Numerical Control System

2013 ◽  
Author(s):  
Zhiqian Sang ◽  
Xun Xu
Keyword(s):  
Real Time ◽  
High Speed ◽  
Computer Numerical Control ◽  
Numerical Control ◽  
Machining Process ◽  
Cnc Machine ◽  
Field Bus ◽  
Nc System ◽  
Tool Paths ◽  
Cnc Controller

Traditional Computer Numerical Control (CNC) machines use ISO6983 (G/M code) for part programming. G/M code has a number of drawbacks and one of them is lack of interoperability. The Standard for the Exchange of Product for NC (STEP-NC) as a potential replacement for G/M code aims to provide a unified and interoperable data model for CNC. In a modern CNC machine tool, more and more motors, actuators and sensors are implemented and connected to the NC system, which leads to large quantity of data being transmitted. The real-time Ethernet field-bus is faster and more deterministic and can fulfill the requirement of data transmission in the high-speed and high-precision machining scenarios. It can provide more determinism on communication, openness, interoperability and reliability than a traditional field-bus. With a traditional CNC system using G/M code, when the machining is interrupted by incidents, restarting the machining process is time-consuming and highly experience-dependent. The proposed CNC controller can generate just-in-time tool paths for feature-based machining from a STEP-NC file. When machining stoppage occurs, the system can recover from stoppage incidents with minimum human intervention. This is done by generating new tool paths for the remaining machining process with or without the availability of the original cutting tool. The system uses a real-time Ethernet field-bus as the connection between the controller and the motors.

Study on High Speed Machining Strategies for Mold

2012 ◽  
Vol 591-593 ◽  
pp. 468-471
Author(s):  
Yong Xia Liu ◽  
Ru Shu Peng ◽  
Qiang Cheng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
High Speed ◽  
Intake Manifold ◽  
High Speed Machining ◽  
Machining Time ◽  
High Speed Milling ◽  
Tool Paths ◽  
Nc Program ◽  
Machining Strategies

The advantages and current problems for the application of high-speed machining technology in mold manufacturing are discussed. The requirements of mold high-speed machining for tool paths are summarized. Using the software of Cimatron E7.0，the NC program of the outer mold for a car engine’s V8 intake manifold is analyzed and optimized designed. Programming technology and optional of cutters have been introduced in detail. In the high speed milling stages, using the new cutters, the hardened mold can be machined to reach the required size, shape and surface roughness, and the machining time is reduced greatly. The method of making high speed NC template based on the software Cimatron E7.0. is introduced. Using this method, the maching efficiency is improved greatly, and the mold’ s surface quality better.

Sign in / Sign up

Export Citation Format

Share Document