Common Defects Of A CNC Machine And Repair Services

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Common Defects Of A CNC Machine and Repair Services

It is human psychology to strive for better. Label curiosity, optimism, growth, development, or success; we always persevere to change. One of those facets makes us who we are, what we are, and where we stand in the ecological hierarchy. Unlike our other counterparts of life forms, we merely don't adapt to the changing environment. Instead, we strive to change the environment. This catharsis is the inherent explanation of all the progress we have made in the story of time, be it evolution, the discovery of metals, monarchy, or machines. In this blog, we will unfold the working and the vulnerabilities incurred by one of the most instrumental pieces of machinery in any industry today, the CNC machine.

What Is A CNC Machine?

A Computer Numerical Control Machine or CNC is pre-programmed computer software that controls the movement of factory tools and machinery and a range of complex machinery which are used in several industries, from manufacturing and E&P to power generation. It surpasses the limitations of manual intervention. Instead, it commands the machining tools with levers, buttons, and wheels, removing inefficiency and the possibility of mishandling or flaws. A CNC system resembles any standard set of computer components to a mere onlooker. Yet, the software programs and consoles of CNC machining make it different from all other forms of computation. Generally, CNC machines include lathes, mills, electric discharge machines, plasma cutters, and water jet cutters. Industries use these as per the cut, shape, or design required. For example, water jet cutters are used for cutting materials that cannot sustain damage from a traditional cutter, such as granite.

Namely, the tools are as such:

Mill - forms complex parts over three to five axes.

Lathe - cuts round shapes along two axes.

Electric Discharge Machine - uses electrical charges to break off small pieces of two conductive materials.

Plasma Cutter - combines electrical arcs with compressed air to create a plasma torch for high-speed cutting of hard metals.

These machines operate as subtractive devices that remove excess material from an entire piece to create the desired shape, distinguishing it from additive processes like 3D printing.

Where Is The CNC Machine Used?

Aerospace Industry

CNC machining can meet the constant need of the aerospace industry for complex and customized parts. To accomplish this with CNC machining, a 5-axis CNC machine is used where a computer controls tools moving along five axes to create the part's design. CNC machining with a 5-axis machine delivers greater efficiency, better surface finishes, and superior cutting speed, making it an ideal option for the aerospace industry.

Electronics Industry

Electronic components carry fine detailing with unusual shapes that require specialty in production. Moreover, many devices require prototyping before going into production and enable the mechanical design to turn into a working prototype for evaluation before choosing to have a specialty machine built for production or ordering a small production run.

Due to the small size of the electronics parts, many parts need precision micro-machining, and the ability to adapt to work on large and small pieces makes CNC machining an ideal and flexible option for the electronics industry.

Medical Industry

The precision delivered by CNC machining is a boon for the medical industry as precision is extremely critical given that medical devices, artificial joints, bone plates, rods, and implants must work within patients and fit their bodies and lifestyles. Implants and patient devices such as insulin pumps must be robust against rigorous use and last for years. They have to be made impeccably well, with components having a smooth exterior and long-lasting construction to be effective. CNC machining also makes parts for larger devices and trim components for fitting implants on or in the body. Be ventilator parts or medical screws, CNC machining delivers all with the highest order of precision, avoiding medical complications.

Power Generation Industry

CNC plays an important role in power generation industries. For instance, it is instrumental in fabricating hydropower turbines and generator components since they are complicated pieces of equipment. They comprise thousands of components in sizes varying from a piece smaller than our index finger to as big as a car. CNC equipment is accurate offering great precision and seamless assembly. For example, Canyon Hydro, the leading manufacturer of Francis hydroelectric turbines, employs a 7-axis CNC machine for fabricating the majority of the parts constituting their 36 Ft long and 25-ton hydroelectric system.

CNC machining can fabricate difficult-to-machine materials in the conventional power industry. The components of a traditional generator are subjected to temperatures as high as up to 2300 degrees Fahrenheit as they generate power by burning fossil fuels. The problem that then arises is not about finding a metal with high thermal resistance but about finding the right method for manufacturing those metals. Even titanium and its alloys which are regarded for having high strength, chatter during metal cutting because of the poor machinability. However, CNC machining is compatible with a broad range of materials. For example, a CNC machine for titanium with a cutting speed of 59 m/min for roughing and around 180 m/min for finishing operations is employed for machining titanium and its alloys. In solar, and wind power systems, researchers are devising ways to replace the conventional form of energy systems with renewable ones by studying the energy efficiency and performance of novel wind turbine blade designs and solar panels. 

Given how instrumental CNC machines are in various industries for their efficiency, accuracy, precision, and performance, it is needless to say that they operate day in and day out and, therefore, must be vulnerable to constant wear and tear. However, like other machinery, CNC machines encounter a set of anomalies, which every industry proactively tries to keep at bay. However, it is unavoidable, and thus it is essential to be ready for such probable defects. 

Common Defects Of A CNC Machine And Their Causes

Improper operation

A CNC machine consists of electronics, electrical and mechanical components that generally encounter faults due to the low-quality of the components, ignorance of cutting parameters (for example, the cutting limit of a particular CNC machine is 500 rpm. but it is being operated more than that limit), and overloading.

Tool misalignment

The very common problems of the mechanical part of a CNC machine are namely misalignment of bed, spindle failure, problem in gear shift mechanism, and problem in automatic tool changer, which are results of overloading and overheating.

Improper lubrication and friction control

Failure in the solenoids of the motor, servo drive of the motor, electrical supply to the spindle drive, short-circuiting, low voltage problems, etc., are some of the common problems of electrical components of CNC. Failure encountered by the moving parts such as screws, slideways, bearing, etc., can be repaired by reducing friction with proper lubrication and using a low friction coating.

Improper maintenance

Some of the most general problems faced by the pneumatic components of the CNC machine are the deformed inside walls of cylinders, used in the actuators, and the deformation of piston or piston rings, resulting in leakage, and malfunctioning of the equator.

Electronic Components of a CNC machine comprise Printed Circuit Boards, enclosures, electronic casings, heat sinks, sockets, semiconductors, etc. Therefore, it can cause failure in the hardware components of the computer systems, resulting in faults in the program (syntax error), operation, testing, and problem search operations.

Improper clamping

Improper clamping of the workpiece leads to poor surface finish and even damage to the tool holder and insert. In addition, when the workpiece is not clamped correctly, it increases the vibrations between the workpiece and the cutting tool. To avoid this problem, one must ensure that the hydraulic pump and the foot switch are running and check whether or not the workpiece is appropriately aligned alongside the rotating and cutting tool axes.

Improper installation

Improper setup of the machine leads to chatter, where the machine or workpiece vibrates uncontrollably. It can significantly damage the tool and deteriorate the machine's condition due to violent vibrations, reducing the service life of the machine. Therefore, one must either reduce or increase the feed rate and use more positive chip breakers to control chatter.

Therefore, routine CNC maintenance is essential to keep these foreseeable defects at bay, including scheduled inspection and a thorough physical check-up of the equipment, control panel, and other parts. Keeping in mind that there are various types of CNC machines, such as drills, lathes, and milling machines, one must always adhere to the maintenance guidelines specific to their CNC machine. At ICC, our qualified service technicians extend quality support, maintenance, testing, replacement, and repair for CNC power supplies, servo and spindle drives, video operator panels, tape loaders, and other program storage devices for brands like Siemens, Allen Bradley, Yaskawa, Emerson, Westinghouse, ABB and many more.