Feature recognition & tool path generation for 5 axis STEP-NC machining of free form / irregular contoured surfaces

This research paper presents a five step algorithm to generate tool paths for machining Free form / Irregular Contoured Surface(s) (FICS) by adopting STEP-NC (AP-238) format. In the first step, a parametrized CAD model with FICS is created or imported in UG-NX6.0 CAD package. The second step recognizes the features and calculates a Closeness Index (CI) by comparing them with the B-Splines / Bezier surfaces. The third step utilizes the CI and extracts the necessary data to formulate the blending functions for identified features. In the fourth step Z-level 5 axis tool paths are generated by adopting flat and ball end mill cutters. Finally, in the fifth step, tool paths are integrated with STEP-NC format and validated. All these steps are discussed and explained through a validated industrial component

Tool path generation for milling of free form surfaces with feed rate scheduling

Upotreba slobodnih (skulptorskih) površina u procesu projektovanja proizvoda raste po eksponencijalnom nivou kako iz funkcionalnih tako i iz estetskih razloga. U procesu projektovanja i izrade slobodnih površina neizostavna je upotreba CAD/CAM softvera. Dok su geometrijski aspekti projektovanja relativno dobro pokriveni, problemi i dalje ostaju kada je u pitanju stvarna proizvodnja slobodnih površina. Glavni problemi su povezani sa određivanjem odgovarajuće putanje alata koja bi obezbedila zahtevan kvalitet obrađene površine, minimizaciju ukupnog vremena obrade, kontrolu intenziteta sile rezanja itd. U radu je prikazan algoritam za generisanje putanje alata zasnovan na kriterijumu održanja sile rezanja na konstantnu unapred definisanu vrednost za procese 3-osne obrade loptastim glodalom. U tu svrhu je razvijen model za predikciju sile rezanja koji je uključen u algoritam za generisanje putanje alata i softver koji je kompatibilan sa svim CAD/CAM sistemima. Eksperimentalno je potvđeno da predloženi algoritam ima brojne prednosti u odnosu na strategije obrade komercijalnih CAD/CAM softvera.The use of freeform (sculptured) surfaces in the product design process is accelerating at an exponential rate driven by functional as well as esthetics demands. CAD/CAM software is a must in their design and manufacture. While the geometric aspects of the design are relatively wellcovered, issues still remain when it comes to the actual manufacture of freeform surfaces. The major issues are related to the generation of the proper toolpaths that would assure the required surface quality, the minimization of the total maching time, the control of the magnitude of the cutting forces, etc. This paper presents an algotithmic procedure for tool path generation based on the criterion of maintaing the cutting forces at a constant pre-defined level for 3-axis ball end milling processes. To this end, a model for cutting force prediction is formulated and incorporated into the tolpath generation algorithm and software that is compatible with all CAD/CAM systems. It has been experimentally confirmed that the proposed algorithm offers a number advantages over the machining strategies used in commercial CAD/CAM software

Tool path generation for milling of free form surfaces with feed rate scheduling

Upotreba slobodnih (skulptorskih) površina u procesu projektovanja proizvoda raste po eksponencijalnom nivou kako iz funkcionalnih tako i iz estetskih razloga. U procesu projektovanja i izrade slobodnih površina neizostavna je upotreba CAD/CAM softvera. Dok su geometrijski aspekti projektovanja relativno dobro pokriveni, problemi i dalje ostaju kada je u pitanju stvarna proizvodnja slobodnih površina. Glavni problemi su povezani sa određivanjem odgovarajuće putanje alata koja bi obezbedila zahtevan kvalitet obrađene površine, minimizaciju ukupnog vremena obrade, kontrolu intenziteta sile rezanja itd. U radu je prikazan algoritam za generisanje putanje alata zasnovan na kriterijumu održanja sile rezanja na konstantnu unapred definisanu vrednost za procese 3-osne obrade loptastim glodalom. U tu svrhu je razvijen model za predikciju sile rezanja koji je uključen u algoritam za generisanje putanje alata i softver koji je kompatibilan sa svim CAD/CAM sistemima. Eksperimentalno je potvđeno da predloženi algoritam ima brojne prednosti u odnosu na strategije obrade komercijalnih CAD/CAM softvera.The use of freeform (sculptured) surfaces in the product design process is accelerating at an exponential rate driven by functional as well as esthetics demands. CAD/CAM software is a must in their design and manufacture. While the geometric aspects of the design are relatively wellcovered, issues still remain when it comes to the actual manufacture of freeform surfaces. The major issues are related to the generation of the proper toolpaths that would assure the required surface quality, the minimization of the total maching time, the control of the magnitude of the cutting forces, etc. This paper presents an algotithmic procedure for tool path generation based on the criterion of maintaing the cutting forces at a constant pre-defined level for 3-axis ball end milling processes. To this end, a model for cutting force prediction is formulated and incorporated into the tolpath generation algorithm and software that is compatible with all CAD/CAM systems. It has been experimentally confirmed that the proposed algorithm offers a number advantages over the machining strategies used in commercial CAD/CAM software

Manufacturing Processes of Integral Blade Rotors for Turbomachinery, Processes and New Approaches

Manufacturing techniques applied to turbomachinery components represent a challenge in the aeronautical sector. These components are commonly composed of high resistant super-alloys; in order to satisfy the extreme working conditions, they have to support during their useful life. Besides, in the particular case of Integrally Bladed Rotors (IBR), they usually present complex geometries that need to be roughed and finished by milling and grinding processes, respectively. Thermoresistant superalloys present many challenges in terms of machinability what leads to find new alternatives to conventional manufacturing processes. In order to face this issue, this work presents a review of the last advances for IBR manufacturing and repairing processes.We are grateful to Basque Excellence university Groups IT IT1337-19, and Ministry of economy project IBRELIABLE (DPI2016-74845-R), and Elkartek PROCODA KK 2019-004

An analytical model taking feed rate effect into consideration for scallop height calculation in milling with torus-end cutter

International audienceFeed rate effect on scallop height in complex surface milling by torus-end mill is rarely studied. In a previous paper, an analytical predictive model of scallop height based on transverse step over distance has been established. However, this model doesn’t take feed rate effect into consideration. In the present work an analytical expression of scallop height, including feed rate effect, is detailed in order to quantify feed rate effect and thus to estimate more precisely the surface quality. Then, an experimental validation is conducted, comparing the presented model predictions with experimental results. Actually, the share of the scallop height due to feed effect is highly dependent on the machining configuration. However, most of time, the feed effect on total scallop height values is far from being negligible