Metal spinning, also known as spin forming or metal turning, is a metalworking process that dates back several centuries. It involves rotating a metal disc or tube on a lathe and shaping it using various tools to form axially symmetric parts. This traditional technique has been transformed significantly with the advent of Computer Numerical Control (CNC) technology, leading to the modern process known as metal CNC spinning. Metal CNC spinning combines the precision of CNC machining with the traditional art of metal spinning. This advancement has revolutionized the manufacturing of symmetrical metal parts, allowing for greater accuracy, repeatability, and efficiency. The invention and evolution of metal CNC spinning is a fascinating story that intertwines with the broader development of metalworking Read more
Molybdenum crucibles are essential containers used in rare earth smelting furnaces, quartz continuous melting furnaces, and sapphire single crystal growth furnaces. The quality of molybdenum crucibles directly affects the quality of sapphire single crystals, especially in sapphire single crystal production. With the increasing demand for high-quality sapphire single crystals due to the growth of the LED industry, the requirements for molybdenum crucibles have become more stringent. Traditional methods of producing molybdenum crucibles cannot meet the growing demand. This study introduces spinning processing as a new technical approach to address the challenges of producing molybdenum crucibles. High-Temperature Processing: Due to the poor plasticity of pure molybdenum material, spinning processing cannot be completed at room temperature. High-temperature tensile tests show that pure Read more
Recently, an expert team from the China Aerospace Corporation’s First Academy, Factory 211, conducted a preliminary acceptance review of the CZ3000/2 CNC spinning machine produced by the Seventh Academy’s Factory 7102. This machine is the largest spinning processing machine independently developed in China. It is capable of forming cylindrical, conical, hemispherical, and other curved-line parts from materials such as aluminum alloys, stainless steel, and zirconium oxygen-free copper, meeting specific product process requirements for both cold and hot spinning. The equipment weighs 110 tons, with a maximum single-wheel spinning pressure of 400 kN and a maximum processing diameter of 3 meters. The machine features good stability, ease of operation and maintenance, and reliable safety. It is the first device to utilize Read more
In July this year, the Lu Wei aluminum wheel hub production line, with a total investment of over 1 billion yuan, began trial operation in Fuzhou, Jiangxi. This is the first digital, continuous, and automated forging aluminum wheel hub production line in China and abroad, marking the industrialization stage of the Demma “Four-Dimensional Manufacturing” project, which has undergone 8 years of research and development. “Four-Dimensional Manufacturing” is an advanced method based on the traditional three-dimensional manufacturing, introducing new mechanical considerations through force counteraction and balance principles to form the “Four-Dimensional Manufacturing” working method. By innovating and transforming traditional equipment such as forging presses, “Four-Dimensional Manufacturing” effectively achieves energy saving, emission reduction, and green manufacturing. For example, in the aluminum wheel Read more
Spinning is a process method that uses a tool to continuously apply pressure to a very small part of the workpiece to gradually shape it. Spinning deformation is a local progressive deformation, and its progressiveness is similar to swing rolling. According to the deformation characteristics of spinning, the spinning process can be divided into two categories: ordinary spinning and high-power spinning [1]. Using software to simulate the high-power spinning process can clearly obtain the required data and effectively prevent defects in actual production. Software modeling and simulation In this paper, the metal forming software Simufact is used to simulate the high-power spinning process. The simulation process ignores the influence of gravity and metal inclusions, and ignores the influence of temperature Read more
In order to machine 3 mm thick large-size cylindrical Al alloy part with curvilinear generatrix followed by straight- walled section, power-conventional spinning combination method supplemented with heat spinning via horizontal CNC spinning machine was explored through process tests, namely, power spinning of the conical curve section at the small end fol-lowed by multi-pass heat conventional spinning. It has been proved that power-conventional spinning combination method is feasible for the machining of large-size Al alloy cylindrical parts with cone-curved profile. Part blank design, necking amount of conventional spinning and part expanding are primary factors affecting the success of the above spinning processes. A certain aluminum alloy cylindrical part is a large-sized cylindrical part with a small taper curved generatrix connected to Read more
Variable Air Volume (VAV) Boxes are critical components in modern Heating, Ventilation, and Air Conditioning (HVAC) systems, particularly in large commercial and institutional buildings. Unlike Constant Air Volume (CAV) systems, which supply a constant airflow at variable temperatures, VAV systems adjust the amount of air supplied to different zones within a building based on the specific demand of each area. This approach not only enhances occupant comfort but also significantly improves the energy efficiency of HVAC systems. The concept of VAV systems dates back to the mid-20th century, coinciding with the increasing demand for more energy-efficient and controllable HVAC systems. The development of VAV technology has paralleled advances in building automation, allowing for more sophisticated control over the indoor environment. Read more
A metal lathe is a fundamental machine tool used in metalworking for shaping metal and other materials through rotational cutting. It has been essential in manufacturing and engineering for over a century, evolving from manual lathes to sophisticated computer-controlled systems. The speed at which a metal lathe spins, or its rotational speed, is a critical parameter that influences machining efficiency, surface finish, tool wear, and overall productivity. This article provides a comprehensive overview of the factors affecting lathe speed, the types of lathes, and the implications of different speeds in metalworking. Historical Context Of Metal Lathe Rotation Speeds The metal lathe’s origins can be traced back to ancient Egypt and Greece, where primitive forms of the lathe were used for Read more
Cam mechanisms, characterized by higher pairings, enable followers to achieve predetermined motion patterns. They present several advantages and disadvantages as follows: Advantages: The motion law of the follower can be arbitrarily designed. Cam mechanisms are suitable for applications requiring precise follower movement and can accommodate intermittent motion. The ratio and number of motion to dwell times can be freely specified. They provide high-speed initiation and reliable, accurate actions. By designing the appropriate cam profile, followers can move according to the specified law. Designing medium to low-speed cam motions is relatively straightforward. With the widespread use of CNC machines and computers, especially in recent years, computer-aided design and manufacturing have made cam profile machining much less challenging. Disadvantages: Ensuring good lubrication Read more
The Venturi effect is a principle in fluid dynamics that occurs when a fluid flows through a constricted section of a pipe, resulting in a reduction in fluid pressure and an increase in fluid velocity. This phenomenon is named after the Italian physicist Giovanni Battista Venturi, who first described it in 1797. Principle Of Venturi Effect The Venturi effect can be explained through the principles of conservation of energy and the continuity equation. According to the conservation of energy, the total energy of a flowing fluid must remain constant. This total energy includes the fluid’s kinetic energy, potential energy, and internal energy (pressure). When a fluid enters a narrow section of a pipe, its velocity must increase to satisfy the Read more
Spinning, a fundamental process in the textile and metalworking industries, involves the manipulation of materials to create fibers or shapes through rotation. There are several variations of spinning, with power spinning and normal spinning being two primary techniques. This article elucidates the differences between power spinning and normal spinning, highlighting their unique applications, advantages, and processes. Normal Spinning Normal spinning, also known as conventional spinning or hand spinning in the context of textiles, is a traditional method employed for centuries. In metalworking, normal spinning refers to a technique where a metal disc is rotated at high speed and formed into an axially symmetric part. Process Textile Spinning: Material Preparation: Raw fibers, such as cotton or wool, are cleaned and carded Read more
The newly developed integral hollow shaft roller is created by directly reducing and spinning the ends of a thin-walled tube to form the shaft neck. Through diameter-reduction spinning experiments on the rollers, this paper summarizes the deformation process of thin-walled tubes, analyzes the plastic deformation laws, forming mechanisms, changes in metallic properties during the spinning process, and methods to control and prevent defects in diameter-reduction spinning. Belt conveyors are widely used in mines, ports, and other work sites, with rollers being their primary component and used in large quantities. Addressing defects in the existing roller structures, we have developed a new type of roller with a hollow shaft. The structure of the new roller is shown in Figure 1. The Read more
In industrial control systems, devices such as proximity switches and photoelectric switches are commonly used for positioning tasks. With the continuous development of industrial control, rotary encoders have emerged, characterized by: Informationization: Besides positioning, the control room can also determine the exact position. Flexibility: Positioning can be flexibly adjusted in the control room. Ease of Installation and Safety: They are easy to install, safe, and have a long service life. A rotary encoder can measure distances ranging from a few micrometers to tens or hundreds of meters. Using a single rotary encoder can eliminate the need for multiple proximity switches and photoelectric switches, addressing issues like complicated mechanical installations, susceptibility to damage, and interference from high temperatures and moisture. Due Read more
