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April 17, 2022 at 11:53 am in reply to: HMC or VMC, which is preferred more in terms of CNC machine design? #1627
What Is the Difference Between a CNC VMC and a CNC HMC?
1. Differences in Structure Choosing between VMC and HMC is a difficult task.
The Z-axis structure is the major distinction between the VMC and the HMC. The fundamental difference between both is that the VMC’s Z-axis goes vertically downward to complete the processing, whereas the HMC’s Z-axis moves horizontally downward to complete the processing.
2. Workbench Variation Choosing between HMC and VMC is a difficult task.
The VMC’s worktable is commonly a T-slot worktable with a cross slide arrangement. The vertical movement of each other is controlled by two sets of motion motors. The Y-feeding guide rail covers the X-feeding worktable. The HMC’s worktable can only move in one of two directions: X or Y. The worktable is usually a rotary worktable with a dot matrix screw hole table, and choosing an interchangeable double worktable is quite simple.
3. CNC VMC and HMC Machines Process Various Parts
The vertical machining center can handle disk, sleeve, and plate components. It usually has three linear motion coordinate axes, and to process spiral parts, a rotary table that spins along the horizontal axis can be mounted on the worktable.
The horizontal machining center may process components with more than two sides, as well as parts with holes and surfaces oriented radially around them, such as box and shell parts; if the position accuracy of the processed parts is critical, a high-precision horizontal machining center should be used.
4. VMC and HMC Advantages and Disadvantages
1) HMC – Benefits: When compared to VMC, the HMC is easier to remove chips during workpiece processing, and it is better for processing intricate recesses and the mold cavity. The horizontal machining center (HMC) can process huge workpieces due to its structural advantages. Horizontal machining centers can process workpieces that are difficult or impossible to process on vertical machining centers.
– Disadvantages: the HMC occupies a big space, has a complicated structure, and is more expensive than the VMC. Debugging the horizontal machining center’s program is inconvenient. Observing the tool movement path during processing is not recommended. Loading and unloading the workpiece is inconvenient.
The horizontal machining center is more suitable for processing box-like workpieces and can process the peripheral surface of the box-like workpieces, as can be seen from the advantages of the HMC. However, there are numerous drawbacks in program debugging, tool trajectory observation, workpiece loading and unloading, and workpiece measurement, so we must consider the disadvantages and benefits of the horizontal machining center carefully.
2) VMC – Benefits: It takes up a little amount of space, has a simple structure, and is reasonably priced. It’s easier to set up and configure the program, and it has a larger number of applications.
– Drawbacks: It can’t process pieces with a lot of height. When cutting a hollow or a concave shape, chips are difficult to remove. It may harm the tool, ruin the treated surface, and disrupt the smooth processing in severe circumstances. It is better suited to processing workpieces with tiny dimensions in the height direction.
When deciding between HMC and VMC, examine the processing object, processing technique, processing scope, and equipment cost. The machining center is currently evolving in the compounding direction. Factors like production efficiency, processing technology requirements, and equipment finances must all be addressed before choosing a machining center type, and the rationality of the selection plan must be measured by cost performance and applicability.April 17, 2022 at 11:50 am in reply to: What are the 7 qc tools used in quality management? #1626
Quality Tools: What Are They?
The 7 basic tools of quality, sometimes also referred to as 7 QC tools – represent a fixed set of graphical tools used for troubleshooting issues that are related to quality.
They are called basic quality tools because they can be easily learned by anyone even without any formal training in statistics. Dr. Kaoru Ishikawa played the leading role in the development and advocacy of using the 7 quality tools in organizations for problem-solving and process improvement.
The 7 basic quality tools include;
Quality tools are used to collect data, analyze data, identify root causes, and measure results in problem-solving and process improvement. The use of these tools helps people involved easily generate new ideas, solve problems, and do proper planning.
The 7 quality tools were first emphasized by Kaoru Ishikawa a professor of engineering at the University of Tokyo, who is also known as the father of “Quality Circles” for the role he played in launching Japan’s quality movement in the 1960s.April 17, 2022 at 11:48 am in reply to: What should I watch for when buying a used 5 axis VMC? #1625
5-axis machines use a tool that can travel in five directions: X, Y, and Z, as well as A and B, which the tool revolves around. Operators may approach a part from all directions in a single operation with a 5-axis CNC machine, eliminating the need to manually move the workpiece between operations. 5-axis CNC machining reduces time and is perfect for producing complex and precise parts in industries such as medicine, oil & gas, and aerospace. Product teams should be aware of several distinct types of 5-axis machines, including indexed 5-axis CNC machines, continuous 5-axis CNC machines, and mill-turning CNC centers.
In indexed 5-axis CNC machining, the cutting tool only moves in three axes, similar to 3-axis CNC milling, and does not maintain continuous contact with the workpiece. The machining table and tool head, on the other hand, can swivel in two directions automatically between operations. Housings, jigs, and fixtures can all benefit from indexed 5-axis machining. In terms of speed, precision, and the capacity to handle complex geometries, it lies midway between 3-axis CNC milling and continuous 5-axis CNC machining.
The cutting tool and the workpiece can rotate and move simultaneously during continuous 5-axis CNC machining, saving time and allowing operators to create complicated designs with organic surfaces. Continuous 5-axis CNC machining improves surface smoothness, speed, and dimensional stability, but the cost-per-part is the greatest.March 4, 2022 at 10:00 am in reply to: How to effectively conduct factory audits on suppliers? #1460
Factory audits verify that your supply chain complies with local and international requirements, as well as your own company’s standards and, ultimately, your brand’s image standards.
If your suppliers pass all three phases of factory audits, the quality of your supply chain will improve:
1. Audit of Social Compliance
Audits of social compliance are becoming an increasingly significant aspect of all global supply chains. They are carried out in such a way that providers can assess in accordance with local regulations. In China, social compliance audits are the most common. These audits are conducted to ensure that business partners adhere to their company’s commitment to commercial social responsibility.
Professionals with experience in social responsibility audits conduct social compliance audits that follow the SA8000 international standard. Compliance lowers the danger of contributing to environmental and social harm, hence it’s better if the supply chain follows this auditing procedure.
Engagement with stakeholders, a methodical long-term approach, and transparency are all part of China’s social compliance assessments. It aids in the verification of honesty, transparency, and consistency.
2. Audit of Quality Control
The systematic assessment of a quality system is what a quality control audit entails. An audit team or an internal or external quality auditor does it. It is an essential component of a factory’s quality management system. It’s also an important part of a factory’s ISO quality system standard.
3. Audit of security
Security auditing is a broad type of audit that entails a formal review of a factory’s security systems and procedures. This type of audit is a comprehensive and in-depth examination of physical characteristics, policies, and standard operating procedures. It includes a technical and conceptual overview of the factory’s security systems and procedures.
A CNC system’s heart is the machine control unit (MCU). It is used to carry out the following tasks:
• To decode the instructions.
• To decode the instructions that have been coded.
• To generate axis motion commands, use interpolations (linear, circular, and helical).
• To drive the axis mechanisms by feeding the axis motion commands to the amplifier circuits.
• To receive position and speed feedback signals for each driving axis.
• Auxiliary control functions such as coolant or spindle on/off and tool change must be implemented.
Computer Numerical Control is the abbreviation for Computer Numerical Control. A CNC machine is a machine that uses computers to drive a Numerical Control (NC) machine tool. In other words, CNC machine refers to the use of computers to control machine tools such as lathes, mills, slotters, and shapers.
Manufacturers today are under increased pressure to increase throughput, deliver just-in-time delivery schedules, and get them to market faster, all while dramatically minimizing costs. When bottlenecks occur on the CMM, inspection procedures extend cycle times and ultimately increase non-value added quality costs. The speed and efficiency of CMM are therefore essential.
As already mentioned, bottlenecks on CMM are often due to the huge volume of work that has to be done by a limited number of qualified metrologists. CMM programming times also lengthen inspections considerably, because the CMM must be configured for each type of component or subassembly to be evaluated.
Conventional CMMs with probes are slow and not suitable for effectively measuring complex shapes. Other CMMs, with sensors, tend to speed up inspection processes; however, they still need to be used by experts.
Manufacturers are therefore increasingly looking for inspection technologies, such as innovative optical CMMs, that can keep up with the fast pace demanded by demanding production environments and stringent quality assurance and quality control standards.
CMMs are considered to be the best dimensional inspection tools now, are most often used to test a part or assembly to determine whether or not it meets the original design intent. CMMs are integrated into quality assurance or quality control workflows to verify the dimensions of manufactured components to prevent or resolve quality issues.
The advantages of using CMMs over manual inspections or checks performed with conventional metrology instruments, such as micrometers and height gauges, are: accuracy, speed, and reduced human error.
Thanks for your professional response! 🙂