Archive for the ‘Uncategorized’ Category
Pros and Cons in Sheet Metal Manipulation with CNC
The advancement of technology allowed sheet metal designs to be more complicated. However, this level of complication has surpassed human capabilities (as far as mass production is concerned). The required accuracy for the intricacy of the designs can only be provided by Computer Numerical Controlled (CNC) machines.
The Punch press
An example of a CNC machine that is used in sheet metal manipulation is the punch press. This device uses hydraulic, pneumatic, or electrical power to exert immense pressure to shape the metal and cut it according to the designs. Being computer aided, this machine is capable of rapid positioning and therefore, fast production. Manual punch presses compromise speed for accuracy therefore lessening efficiency.
The punch press works by receiving instructions from a program in a computer. This allows the operator to sit back and relax once the cycle (rapid positioning, punching, and switching of tools) has been initiated. These machines perform operations with accuracy that is measured by the thousandth of an inch.
Introduction of these machines into the sheet metal industry sped up production significantly. And to stay competitive in the global market, such an edge would be needed. However, technology finds ways to improve on this.
New devices
Today, presses have newer versions. The turret punch press is capable of sorting sheet metal into their respective design classes. This means that the new punch presses can operate virtually unattended. Steel manufacturing companies invest in these machines should it mean streamlining of their jobs and increasing production capabilities.
Newer CNC machines can even alert operators who are not in the area if a problem crops up during the sheet metal punching process. This happens by enabling the CNC machine to keep track of the operators’ phones. Therefore, the workload of the operator is relaxed to the point that he/she does not even need to be in the area of operation.
The drawback
However, these machines do not come cheap. A lot of time, money, and effort have to be spent in order to operate the machine to its fullest capacity. Furthermore, there is a shortage of people who are skilled enough to operate such machines. An operator has to be knowledgeable with BASIC programming language, fundamental machining processes, design awareness, and accessory functions.
Furthermore, knowledge of Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) is a big factor in being able to control such machinery. So the capital that you have to spend on understanding these machines have to be justified with the caliber of the operator that you have.
Another drawback that is present is the compatibility of the machines with the current technology that the company has. If they are incompatible, it takes even more time and money to replace current facilities or to restructure the factory in order t accommodate such devices.
The Conclusion
so, if you’re a big company and you want to stay in the race, you have to consider and reconsider investing into these things. The investment may be worth itself a hundred times over but it is a rather risky choice to step into something new. You have to restructure your work schedules, change the requirements for operators, and provide proper training to operators that you want to keep.
These things will cost a lot and will take a while before they reflect what they really are worth.
The Different CNC Machines
CNC has different applications depending on the machines that operate on it. So if you’re a budding operator, you should know the most common machines that can operate on CNC.
Milling
Milling machines are common CNC machines. These devices are used in the shaping of metal and other solid materials. It is basically a rotating cutter and a table. Milling machines are capable of complex toolpaths as the cutter is not limited to a sideways movement but allows for an “in and out” motion. This movement is precisely controlled by moving the table and the cutter relative to each other. Cutting fluid is then pumped in to lubricate and cool the cut and to remove any swarth that is generated by the cut.
Lathes
Lathes are machines that perform different operations such as sanding, cutting, knurling, deformation, or even drilling. These machines work by spinning various solid objects and then using tools that are symmetric to the axis of rotation. A lathe machine has a single tool in which the workpiece is worked against the tool. The tool is then worked alongside or into the workpiece in order to generate the feed.
Lathes can be used for different operations.
Machining Centers
These are more complex CNC machines that combine milling and turning. As milling was described earlier, turning will be the focus of this section.
Turning is the process by which a central lathe is used in conjunction with the rotation of the material to be turned. The cutting tool is then moved along the two axes of motions to produce accurate dimensions.
Combining turning and milling can produce extremely precise components. And that is what these machines are used for. However, due to the complexity of these machines, operators have to be specialists in order to be able to operate with maximum efficiency.
Electrical discharge machine
An electrical discharge machine (EDM) creates cavities in metals by emitting electric sparks. This process requires an electrode, coolant, a power source, and a tank. The cycle is accomplished by connecting the workpiece to one side of the power supply and then placing it in the tank. An electrode (made in the shape of the cavity required) is then connected to the other side of the power supply.
The tanks is then filled with coolant and the electrode is lowered until a spark jumps between the work and the electrode. As the coolant is a dielectric substance (resists electric currents), it requires a smaller difference in distance in order for a spark to jump through. This means that when the spark appears, the dielectric property has been overcome. The spark then dislodges material thereby creating a cavity in the shape of the electrode.
CNC systems
CNC systems are complex machines that transfer and store data regarding the operation mechanism of the machines. Motion programs include point to point control, straight cut control, and contouring control.
Point to point control means the control of the tools from one point to another in the coordinate plane. This method of control is commonly used in drilling and boring operations.
Straight cut control is the method by which a tool is moved in all axes of the machine. The tool also has the ability to move in a 45 degree angle.
Contouring control is the means to create a toolpath. It moves the tools by interpolating points or coordinates that make up the path for the tool to follow.
The Basic Parts of a CNC Machine
If you carve your name on a wood using a very sophisticated font, you’re lucky if you’ll finish your first name in 24 hours perfectly. Years ago, wood crafting and metal crafting are very expensive massive- labor industries because every aspect of the manufacturing is done by hand. There was minimal machine intervention but the designs were still as intricate.
Today, with the help of technology, wood carving, metal molding, cutting and even finishing can be done simultaneously with minimal hands involved. In fact, a company is deemed unproductive if it mass produces products every day BY HAND.
CNC (Computer Numerical Control) machines are in demand in industries where hands are better off pushing buttons than doing actual labor. Businessmen are raving about this wonder-machine because it is accurate, speedy and flexible.
The CNC machine is actually a factory of its own. There are different parts that have specific functions. Let’s get to know the “factory workers”.
THE VICE
The Vice is what holds the material which is to be cut or molded. It is important that the vice must be tight; so the material will be held securely. When the CNC machine starts to operate, the material will dash out of the vice if it is not secured. The vice usually works like a clamp that needs to hold the material not just securely but also in the right position.
THE GUARD
The Guard—just like any other guard—works like a “protection” to the person operating the CNC machine. Once the CNC starts working, scraps of the material can “shoot off” at high speed. This is very risky for the operator if a piece hits him/her. The guard completely covers all the hazardous sides of the CNC machine.
THE CHUCK
The chuck holds the cutting tool. Sophisticated designs require maximum chuck precision so the actual design can be realized.
THE MOTOR
The motor rotates the chuck at very high speed. It is hidden and protected inside the machine. You have to take care of this part very carefully. Nowadays, cooling and lubrication is automated in most CNC machines. Usually, if this part doesn’t function well, it is the most difficult to treat. It is advised to have a CNC technician handy all the time.
THE LATHE BED
Like the sea bed, this is the sturdy base of the CNC machine. It is connected to the headstock and aids the carriage and tailstock to be parallel with the spindle’s axis. It is securely bolted so it remains unshaken by the vibration of the machine when it starts operating.
THE CUTTING TOOL/ CUTTER
This is the where the first-level shaping occurs. The cutter is usually made from high quality steel so as to cut the specific material fed to the CNC machine.
As a businessman, it is important that you get to know your employees, bond with them and earn their respect without scaring them. When you have CNC machines working for you, it is equally important that you understand them well. Do not be fooled by the CNC machine salesmen who court your interest because they are usually just after your purchase.
You have to master what comprises these machines, what makes them dysfunctional and most of all, what makes them stay in your company. Just don’t start talking to them. That would be really, really, dysfunctional.
Programming CNC Machines With G-Codes
Ever since the industrial revolution started, the demand to create precise instruments and products is an important factor in large scale manufacturing. Belts, screws, Drills and all movable parts needed to create other products in the assembly line must all be exact and compatible, thus extra care must be taken in order to ensure that all moving parts match perfectly. Computer Numerical Controlled programming has become an extremely important part of this process.
Computer Numerical Controlled Machines are useless without any programming. CNC’s rely on pure hard codes in order to execute commands that the Machine Operator wants to do, therefore not only is it needed to learn the mechanics of the whole Computer Numerical Controlled Machine but it is also at the utmost importance that the Machine operator knows how to communicate with the machine, and that is by using G-codes.
Preparatory code/ functions or much commonly called as G-codes are functions in the Computer Numerical Control programming language. The G-codes job is to manage the position of the tool as well as control the step by step commands during the actual work. Basically the G-codes are the most important part of the Computer Numerical Control Programming algorithm.
There are other codes involved in the programming of CNC’s such as M-codes that manages the machine, T-codes for managing the tools, and F-codes for the tool feed and tool speed controls. All of these codes are created in a Computer Aided Manufacturing (CAM) software.
G codes as well as the others use the RS-274D as the recommended standard for the Computer Numerical Controlled Machines. This standard was developed by the Electronic Industry association during the 1960’s. These standards provide a basis for the creation of Computer Numerical Controlled Programs.
First designs of these standards came from punched paper tapes as the medium standard for data interchange, but now ASCII character bit patterns are the standard for the representation.
G-Codes
Lets discuss the g-codes further, as what I have said earlier G- codes constitute only a part of the Computer Numerical Control Program, in the whole programming algorithm, they are denoted by the letter G, Basically it is a code telling the machine what kinds of actions to perform in a step by step basis, examples of these actions would be rapid move, controlled feed moves that would bore holes, a work piece cut routed to a specific dimension, change a pallet, and set a tool information such as offset.
After creating each part of the codes, the algorithm is compiled in the Computer Aided Manufacturing (CAM) software. The CAM software basically use translators called post processors to output the code optimized for a certain machine type. Often times, post-processors are often used to allow users to enable further customization.
G-codes can also be used to create outputs for Computer Aided Design systems used to design printed circuit boards (PCB). Any software must be customized for each type of machine tool that it will be used to program. Some G-codes are written by hand for volume production jobs.
Some Computer Numerical Controlled machines use conversational programming. Conversational programming is an easier way to program CNC machines because it is more “user friendly” because it uses a wizard like program that hides the G-codes into plain view. Some Popular examples of this kind of CNC machines are the Southwestern Industries’ Proto TRAK, Mazak’s Mazatrol, and Mori Seiki’s CAPS conversational software.
Conclusion
With these kinds of further sophistication in programming Computer Numerical Controlled Machines, it is expected in the future that programming would be much easier for its machine operators.
The Desirable Intervention of CNC Machining
Industries find many uses of CNC machining. Woodworking shops and some other industrial settings make use of the Computer Numerated Control technology behind these machines. Large, repetitive tasks requiring speed, efficiency and accuracy are performed automatically as programmed by CNC machines. The full name of CNC is computer numerated control.
Drilling a hole repeatedly at certain intervals is done more efficiently by CNC routers. Inconsistent work caused by human error or fatigue is eliminated. Products of manual calculation and drilling turn pale in comparison. Wood routers do well in cutting or shaping grooves and hollows in wood.
Computer programming and robotic operation are used in CNC milling devices which are considered as specialty equipment. The CNC changes as it decides the tool needed for an operation. This equipment allows moving the part in order to get the desired outcome from the work piece. This is in addition to the task of shaping wood or metal that it usually does. Exact engraving from smallest to the largest is another capability of CNC machines. The same result is done over and over on wood, metal, stone or glass.
By CNC machining, the manufacturing industry nowadays accomplishes properly numerous operations like welding, spinning, bending, gluing, and cutting. This industrial breakthrough is of high importance to those who require efficiency in fiber placement, routing, picking, placing and sawing.
After having been properly set up initially, CNC machines are easy to run and operate. A program is required for CNC machining to function. The machines are managed by the commands intended for them. A medium is used to store encoded commands.
CNC machining for industries means cutting down expenses and costs, and increasing company’s incomes. Understandably, there is a proliferation of its use in most world manufacturers. Every manufacturer seems to have a need for the machines.
They are very pricey or expensive, which means most individuals cannot afford them at all. The price sounds prohibitive for individual use. But, buying used models can be an option to save about half compared to a new one. Buying rebuilt machines is also another option. Major components in these machines are replaced, they are almost as good as new ones. Oftentimes, warranty comes with the purchase of rebuilt CNC machines.
The intervention of CNC machining offers many benefits to industries. The presence of this industrial item brings about other things patrons that will surely derive from it.
The CNC Family
You might have not heard of the CNC before, or what it does, or how it makes lofty manufacturing operations a lot easier. However, CNC machining is dubbed as one of the most important factors of most production processes. The common tasks CNCs machines usually perform are drilling holes, tool changing, cooling and lubrication of separate factory machines at the same time.
Let’s start with a brief introduction. CNC stands for Computer Numerical Control and it has been around since the early 1970’s. Before it was christened CNC, it was called NC, for Numerical Control. When computers were introduced during 1070’s, the name changed. It has stroked almost all manufacturing forms in almost all stages of production. CNC machines either substitute some existing manufacturing processes or combine work with them.
A CNC program is just any other set of instructions. It’s written like a sentence and the order of operation is chronological. The machine will then execute that set of instructions step-by-step. A special series of CNC words/codes are used to relay what the machine is supposed to do. CNC codes begin with letter addresses (like S for spindle speed, and X, Y & Z for common linear axis motions).
When certain codes are arranged together in a coherent method, this group of CNC codes create a “command” that is like a sentence. A common CNC machine will only be needing around 40-50 words/codes to program different commands. See, it’s not very difficult to learn.
Although CNC sounds very independent and do-it-all, there are a few words that you need to know to fully understand CNC operations.
THE CAM
CAM stands for Computer Aided Manufacturing. It simplifies the programming processes which are new, and added to the CNC program regularly. Of course, the easy applications can be programmed with only the simplest machines around: the pen, paper and calculator. However, more complex programs are vital regularly. It is when composing these programs become much more tricky and (worse) tedious.
The CAM is a program that runs on a computer that aids the CNC programmer with the programming. It also works hand-in-hand with the CAD (Computer Aided Design) design drawing (those designs engineers compose/nurture). With the CAM helping, redefinition of the work-piece configuration is not needed. What the CNC programmer is left to do is just to specify the machine operations to be executed and the CAM system will compose the CNC program automatically. Thanks to CAM, programming tediousness will not be a problem to the CNC programmer again.
THE DNC SYSTEM
DNC stands for Distributive Numerical Control. It is a computer that is connected with one or more CNC machines, forming a network. When a program is manually composed and ready to be loaded to the CNC control, it is being typed right into the control. However, this is like using the CNC machine as a luxurious keyboard.
Moreover, if the CNC program is achieved with the help of CAM, it is already in text form and ready to be loaded to the CNC control. The DNC simply distributes the CNC program to more than one CNC machine. Lately, the newest controls are more advanced in terms of networking capabilities and can be networked with, say, the Ethernet.
If it’s your first time to read and learn about the CNC, it may sound so mighty and ubiquitous. It’s about time you learn they also need help from some programming friends such as the CAM and the DNC. No man is an island; but hey, neither are CNC machines.
Translating...
