Development of a postprocessor for a multi-axis CNC milling center

Most of the current college design and manufacturing curricula are primarily focused on computer aided design (CAD), while less emphasis is given to computer aided manufacturing (CAM). A great opportunity has been missed as the benefits of CAD/CAM cannot then be fully learned. Postprocessor plays a vital role in integration of CAD//CAM with computer numerically controlled (CNC) machines. Hence, postprocessor must be developed accurately. This thesis is composed of one paper. Paper I proposes a novel methodology to determine compensation vectors for the post processor of multi-axis milling center. The new approach that has been implemented in Paper I involves derivation of the analytical equations of NC code with compensation vectors for five-axis spindle-tilting type CNC milling machine and experimental procedure to acquire the compensation vectors. This ensures that part would be machined as per the CAD drawing and accuracy within the limits of CNC machine. Furthermore, implementation of this procedure for the development of a post processor would streamline the process of integrating CAM systems for multi-axis CNC milling centers. The integrated system is being used to support research and education projects to accurately and quickly produce parts --Page iv

Pembangunan Modul Pengajaran Kendiri (MPK) keusahawanan dalam topik isu keusahawanan bagi pelajar diploma di politeknik

Terdapat pelbagai kaedah pembelajaran yang telah diperkenalkan termasuklah kaedah pembelajaran yang menggunakan pendekatan pembelajaran bermodul secara kendiri. Kajian ini adalah bertujuan untuk mengkaji kesesuaian Modul Pengajaran Kendiri Keusahawanan dalam topik Isu Keusahawanan yang telah dihasilkan bagi pelajar yang mengikuti pengajian Diploma di Jabatan Perdagangan Politeknik. Antara aspek yang dikaji ialah untuk menilai sama ada rekabentuk modul yang dihasilkan dapat memenuhi ciri-ciri modul yang baik, MPK yang dihasilkan dapat membantu mencapai objektif pembelajaran, MPK ini bersifat mesra pengguna dan MPK yang dihasilkan membantu pensyarah menyampaikan pengajarannya dengan lebih berkesan. Kajian ini dilakukan ke atas 110 orang pelajar semester en am yang mengikuti pengajian diploma dan 4 orang pensyarah yang mengajar subjek Keusahawanan di Jabatan Perdagangan Politeknik Sultan Salahuddin Abdul Aziz Shah, Selangor. Kaedah analisa data yang digunakan dalam kajian ini ialah skor min dan peratus. Hasil daripada kajian ini menunjukkan bahawa rekabentuk modul yang dihasilkan memenuhi ciri-ciri modul yang baik, MPK ini membantu untuk mencapai objektif pembelajaran, MPK ini bersifat mesra pengguna dan MPK yang dihasilkan dapat membantu pensyarah menyampaikan pengajarannya dengan lebih berkesan. Ini bermakna secara keseluruhannya, hasil kajian menunjukkan bahawa modul yang dihasilkan oleh pengkaji adalah sesuai digunakan oleh pelajar-pelajar semester enam yang mengikuti pengajian diploma di Jabatan Perdagangan peringkat politeknik. Seterusnya, beberapa pandangan telah dikemukakan bagi meningkatkan rnutu dan kualiti MPK yang dihasilkan. Semoga kajian ini dapat memberi manfaat kepada mereka yang terlibat dalam bidang pendidikan

Virtual horizontal machining center LOLA HBG 80 for program verification and monitoring

Ovaj rad opisuje konfigurisanje virtuelnog horizontalnog obradnog centra LOLA HBG80 u okviru sistema za programiranje i verifikaciju, kao i u okviru sistema otvorene arhitekture upravljanja. Horizontalni obradni centar LOLA HBG 80 podržan je ekvivalentnom virtuelnom mašinom u CAD/CAM okruženju (PTC Creo i Catia), STEP-NC mašinskom okruženju, kao i u upravljačkom sistemu. Virtuelna simulacija je od suštinske važnosti za obradu, a razvijene virtuelne mašine koriste se za verifikaciju programa i monitoring procesa obrade. Virtuelna mašina u sistemu za programiranje omogućava verifikaciju programa pre slanja na stvarnu mašinu i može da uključuje verifikaciju putanje alata (CLF-Cutter Location File) i verifikaciju G-koda. U radu se takođe govori o mogućnosti primene novog metoda programiranja poznatog kao STEP-NC i pripremi odgovarajućeg okruženja koje uključuje virtuelnu mašinu. Virtuelna mašina u sistemu upravljanja predstavlja poslednji nivo za konačnu verifikaciju programa, kao i sistem za nadzor procesa.This paper describes configuring the virtual horizontal machining center LOLA HBG80 within the programming and verification system and the open architecture control system. The horizontal machining center LOLA HBG 80 is represented by an equivalent virtual machine in a CAD/CAM environment (PTC Creo and Catia), STEP-NC Machine environment, and the control system. Virtual simulation is essential for machining, and the developed virtual machines are used for program verification and monitoring of the machining process. The virtual machine in the programming system allows the verification of the program before sending it to the real machine and includes verification of the tool path (CLF-Cutter Location File) and G-code. The paper also discusses the possibility of applying a new programming method known as STEP-NC and preparing an adequate environment that includes a virtual machine. The virtual machine in the control system represents the last level for the final program verification and the process monitoring system

Virtual horizontal machining center LOLA HBG 80 for program verification and monitoring

Ovaj rad opisuje konfigurisanje virtuelnog horizontalnog obradnog centra LOLA HBG80 u okviru sistema za programiranje i verifikaciju, kao i u okviru sistema otvorene arhitekture upravljanja. Horizontalni obradni centar LOLA HBG 80 podržan je ekvivalentnom virtuelnom mašinom u CAD/CAM okruženju (PTC Creo i Catia), STEP-NC mašinskom okruženju, kao i u upravljačkom sistemu. Virtuelna simulacija je od suštinske važnosti za obradu, a razvijene virtuelne mašine koriste se za verifikaciju programa i monitoring procesa obrade. Virtuelna mašina u sistemu za programiranje omogućava verifikaciju programa pre slanja na stvarnu mašinu i može da uključuje verifikaciju putanje alata (CLF-Cutter Location File) i verifikaciju G-koda. U radu se takođe govori o mogućnosti primene novog metoda programiranja poznatog kao STEP-NC i pripremi odgovarajućeg okruženja koje uključuje virtuelnu mašinu. Virtuelna mašina u sistemu upravljanja predstavlja poslednji nivo za konačnu verifikaciju programa, kao i sistem za nadzor procesa.This paper describes configuring the virtual horizontal machining center LOLA HBG80 within the programming and verification system and the open architecture control system. The horizontal machining center LOLA HBG 80 is represented by an equivalent virtual machine in a CAD/CAM environment (PTC Creo and Catia), STEP-NC Machine environment, and the control system. Virtual simulation is essential for machining, and the developed virtual machines are used for program verification and monitoring of the machining process. The virtual machine in the programming system allows the verification of the program before sending it to the real machine and includes verification of the tool path (CLF-Cutter Location File) and G-code. The paper also discusses the possibility of applying a new programming method known as STEP-NC and preparing an adequate environment that includes a virtual machine. The virtual machine in the control system represents the last level for the final program verification and the process monitoring system

Ultraprecise Single Point Inverted Cutting Strategies for Multi-axis Fabrication of Right Triangular Prismatic Retroreflectors

The optical phenomenon of retroreflection (RR) is described as light rays contacting a surface and being redirected back to their originating source. While applications are many and varied, their primary focus is safety in low-light conditions, and the focus of this research is toward automotive applications. Few geometric shapes are capable of retroreflection. Among them are the lens-and-mirror, and cube corner geometry; however, the right triangular prism (RTP) has been introduced as a viable alternative. This study demonstrates a more efficient fabrication technology when compared to current industry practices. The ultraprecise single point inverted cutting (USPIC) technology was envisioned as a combination of diamond turning and multi-axis machining. The unique cutting kinematics of USPIC required the development of dedicated tooling and a postprocessor for machine automation. Experimental results have demonstrated both the feasibility of this approach, and that RTP arrays fabricated by this technology outperform those fabricated through conventional means

A framework for practically effective creation of postprocessors for 5-axis CNC machines with all possible configurations and working mechanisms

The 5-axis CNC (Computer Numerical Control) machining plays an important role in manufacturing, especially in making parts of complex shapes such as turbine or propeller blades. However, there are always challenges of generating 5-axis CNC machining programs when working with different 5-axis CNC machines of various structures; and 5-axis CNC programs must be automatically generated by CNC postprocessors which calculate the inverse kinematics and convert the Cutter Location data to the CNC programs that are used for operating 5-axis CNC machines. Since the family of 5-axis CNC machines has a wide spectrum of machine configurations, with hundreds of mechanisms of 5 degrees of freedom, it is therefore practically challenging for engineers and CNC machine operators to create CNC postprocessors for specific 5-axis CNC machines. It is more challenging to create CNC postprocessors if engineers or CNC operators do not have strong backgrounds and professional skills in mathematical modeling and kinematics of machines. This paper presents a universal and intuitive framework and practical guidance to create CNC postprocessors for all 5-axis CNC machines, with the focus on a novel mathematical formulation of inverse kinematics of three main groups of 5-axis CNC machines. The case studies of creating CNC postprocessors with the commercially available 5-axis CNC machines were successfully demonstrated, in which the simulation scenarios and experiments were implemented to verify the created CNC postprocessors. The proposed frameworks and guides for generating CNC postprocessors can be conveniently and effectively applied in industrial practices, without the required strong backgrounds and skills for engineers or CNC operators in mathematical modeling and kinematics of machines, especially mathematical modeling of multibody systems

Statistical investigation on effect of Electroless coating Parameter on Coating Morphology of Short Basalt Fiber.

The Objective of the present paper is to investigate the effect of electroless coating parameters, such as Sensitization time (A), Activation time (B) and Metallization time (C), on the coating morphology of the basalt short fiber and the optimization of the coating process parameters based on L27 Taguchi orthogonal design. Coated and non-coated basalt short fiber, typically used with 7075 Aluminium alloy as einforcement, is studied. The effect of coating the short basalt fiber with copper has proved beneficial to interfacial bonding (wettability) between the reinforcement and the matrix. The interface between the matrix and the reinforcement plays a crucial role in determining the properties of metal matrix composites (MMCs). An L27 array was used to accommodate the three levels of factors as well as their interaction effects. From the Taguchi methodology, the optimal combinations for coating parameters were found to be A1B3C3 (i.e., 5 min. sensitization time, 15 min. activation time and 3 min. for metallization time). In addition, the interaction between pH value and the coating time and that between the coating time and the temperature, influence the coating parameters significantly. Furthermore, a statistical analysis of variance reveals that the metallization time has the highest influence followed by the activation time and the sensitization time. Finally, confirmation tests were carried out to verify the experimental results, Scanning Electron Microscopic (SEM) & Energy Dispersive Spectroscope (EDS) studies were carried out on basalt fiber