Integration between CNC machines and smart devices has been slow in coming for many machinists. The industry can be conservative, and many people are mentally still in a world that has barely put down the slide rules of old. However, your smart devices can do a lot that will have your CNC machining operation working better than ever.
Scheduling maintenance on a CNC machine used to be part marking it on a calendar and part simply checking it over carefully to find any wear on a reasonably regular basis. In the modern world, your smart devices can make the process easier by both automatically pinging you when maintenance should be performed, and even checking subtle changes to the speeds of the motors or flow of power through the device as a diagnostic your eyes cannot see.
Smart devices can often identify the angles of objects as simply as pointing them at the angle to be measured and essentially taking its picture. By doing this, the smart device can aid you in selecting the angle by which you are going to make a given cut on the materials. The smart device may even be able to aide you by helping determine the cut depth and whether you are using the best possible cutter.
Cut Course Planning
Cut courses can be determined through a variety of calculations CNC machinists are required to know. However, human error does still play a role. Thus, the less direct calculating you do, the better for your CNC machining. Allowing your smart device to suggest the courses of your cuts can reduce your mistakes, as the smart device requires few inputs from fallible human sources.
Have you ever been curious if a given material would be ideal or simply “okay” for a given cutter? With a smart device, you can research the relative merits instantly, and even set up automated warnings to yourself if there is the potential for cutter damage due to an incompatibility between the blade and the material.
Smart devices integrate well with CNC machines. With open-mindedness, the experience is an even better one.
The training of CNC workers is vital to running a shop properly. When your workers are not properly trained, they are not assets but liabilities. With effective training, your operators can get a lot done for you.
The Basic Basics
Often, this involves taking people who have never worked in a shop before. The first part of training comes down to safety in the shop, interpreting tolerances, and using measuring devices. Once those are mastered, you can continue with the reading of blueprints and shop math. After the trainees have gotten the feel for the most basic topics that all CNC workers need to know, you can begin moving on to more specific training related to the machines themselves.
Which Machine They Will Run
What are the various components of the machine that each given CNC operator will be using? The learners need to know about the axes and how these are to be programmed into the machine. They also need to know about the spindle, how to change the tools, how to change the pallet, and every other part the young operator is eventually going to interact with. There should not be a single button or switch with which the learner is unfamiliar by the end of this portion of the training. While it might seem like overkill for the learner to be able to field strip the CNC machine like a soldier can do with their rifle, this level of understanding of how every component in the machine interacts with every other component would be the ideal state.
Compensating Within the Machine
Every part of a CNC machine, as well as every part of a CNC worker’s training, needs to involve compensators, which are also used for the cutter radius. Turning centers intimately involve tool nose radius compensation, offsets for wear, and geometry offsets. The learner must know how to assign program zero, attach the cutting portions of the tools, and determine how much offset is necessary for each given tool length to ensure both an accurate cut and one that will not damage the equipment.
There is a lot to learn in CNC work. Covering every relevant aspect is crucial to an effectively run operation.
With a CNC lathe, you can expand your productivity due to solid feed speeds. Further, you can focus on repetition that allows you to produce many of the same piece. Finally, a CNC lathe lets you think a couple of steps ahead for work that may require several pieces to be completed effectively.
The speed of your feeds is an important part of how a CNC lathe increases your efficiency. Being able to place a piece into the device with a specific orientation and have the speed be precisely known takes away much of the guesswork that is usually associated with traditional manual milling techniques. The less adjustments that you need to make in order for your CNC device to function as it is intended to, the more efficiently you can prepare the next piece while the machine is working on the current piece.
More of the Same
There is a high level of efficiency that you gain when you can produce a virtually unlimited number of the same type of piece. With CNC lathes and their ability to be programmed for repetition, you essentially have a backup person that can handle the lion’s share of the cuts and adjustments. Once you have your axes properly calibrated, the coordinates of your spindle’s movement and the cuts all planned out and you have braced the pieces in a solid and repeatable manner, you and your machine can essentially become a small scale assembly line with relative ease. Being able to produce many pieces of the same type without having to commit many of your mental resources is an extreme measure of efficiency.
Perhaps the most important way that your CNC lathe is able to expand the efficiency of your operation is when you can think beyond the current piece to a few pieces down the line, this expands on your ability to machine different parts that together serve a larger and more complicated whole. Having the ability to think a few steps ahead, and plan what cuts your machine will be making once the current set is done, frees up your mind to make higher level decisions than simply crunching the numbers.
Your router will, usually, always turn in the same direction, but an upcut versus downcut router can make a significant difference to the end results of your CNC operation. If you use the incorrect bit for the job, this difference can result in poor feeding or even in visible damage to the piece being worked upon.
The speed of your feed is important to understand. The CNC machine will naturally have to have the path modified if you use a cut that moves in the direction of the blade’s movement. If the blade is fed too quickly, it can make a less effective cut than if there is a more relaxed feed speed. Changing the feed speed can also be useful depending on how much is to be removed to make the prevention of buildup easier.
The direction of the bit’s movement and the direction from which it originates both matter to the cut. Among the debatable aspects of an upcut versus downcut router is from which direction you are approaching the piece versus the spindle’s rotation. In every case, you want to avoid potentially unseating the piece from its restraints, and attempting to take off too much at a time can damage or even snap the bit regardless of its orientation.
When you use upward cutting bits, you will often find greater difficulty in chip ejection. Fighting gravity as well as the rigidity of the materials is of importance because of heat and premature wear on the bit. This influences the speed at which you would be advised to feed the piece as well as the speed of the spindle and how often you have to disconnect to ensure the bit is clear.
Visibility in the Completed Project
In many cases, the speed at which you have the bit approach the piece can result in murmuring, particularly for upward cuts from the bottom. For pieces that will be visible in the finished product, downward cuts are often superior for their ease of keeping a clean cut. However, adjusting the speed can compensate for this to an extent.
If you plan to invest in a new CNC machine, consider the capabilities as determined by the number of axes. In standard CNC machines, the machining tools can function in three axes. The machining center will move along the x- and y-axes of the equipment to carry out the required machining on the part being made. The cutting tools incorporated in the set-up can also move up and down along the z- axis during machining.
A 3-axis machine is sufficient for most standard manufacturing applications. If you are handling more complex work and creating intricate parts with your new equipment, you should consider acquiring a 5-axis machine.
What is 5-Axis Machining?
5-axis CNC machining design makes it possible for the machine to move its cutting tools through the material being machined in 3D space along with rotation about the center of the spindle holding the cutting tools, as well as their inclination (the additional two axes)—the same kind of freedom, more or less, which the wrist of the human hand has. The machine functions on the x-, y-, and z- axes, just like conventional equipment. The difference between 3-axis and 5-axis CNC machining is the extra two axes. These are known, normally, as the a- and b- rotary axes.
The a-axis is the fourth. It refers to the rotational movement around the z-axis. The b-axis is the fifth. It allows for the inclinational movement around the basic y-axis. During the process of 5-axis CNC machining, the part or tooling can be moved in all five directions simultaneously. There are infinite design possibilities for manufacturing parts.
Advantages of 5-Axis Machining
When you choose 5-axis CNC machining, the potential for increases in productivity is high. This is because you can create parts and custom products in a single setup. This saves time and energy when compared with a multiple step process. There is less fixture preparation required, so labor and time costs are minimal. Higher efficiency means more profits. This type of machining setup also promises higher accuracy and repeatability because the workpieces are not moved through several work stations.
A 5-axis machine can be expensive. Evaluate your needs and financial resources and do your research before committing to a purchase.
Proper maintenance of your CNC machines is essential for a successful machining operation. The practice will promote efficient performance of the equipment which translates into higher productivity. The servicing tasks will also prevent premature breakdown and complete failure of your machinery. Consequently, you will be able to avoid unexpected downtime and high repair charges. Here are some simple guidelines on preventative maintenance for CNC machines.
Lubricate the Components
There are multiple moving components in all CNC machines designed for manufacturing purposes. These should be lubricated or greased regularly to ensure smooth movement and performance. If the surfaces of pertinent parts are dry, friction will be generated during operation. This will translate into premature wear of the affected surfaces. In addition, your machines will become more prone to overheating and subsequent damage. You should note that the wrong lubrication could affect functionality. Therefore, check the owner’s manual for suitable recommendations.
Clean the Machine
You should inspect the CNC machine and perform housekeeping tasks after every shift. Typically, when the equipment is used for any work, chips of the raw materials and other forms of debris will fall on the surfaces. Moreover, most workshops and industrial set-ups are exposed to environmental dust and dirt. If the machinery is not cleaned, these small materials will flow into the moving components. When another shift is carried out, the accumulated dirt and debris will cause friction and wear and might even damage other sensitive internal systems. Daily clean-up will prevent these detriments.
Service the Peripherals
Numerous accessories and peripheral components are incorporated into CNC operations to promote productivity and convenience. These can include cooling systems, chip conveyors and work-holding fixtures. While these are not per se part of the primary equipment, they can affect overall performance. Therefore, you should perform servicing tasks for them as part of your maintenance program. For example, you should ensure that your work-holding fixtures are aligned, the coolant nozzles clear and chips cleared. This will minimize total operational downtime.
When establishing a preventative maintenance program for your CNC machines, you should take into account the schedule recommended by the manufacturer for optimal results.
The basics of metrology begin as a method by which any given unit of measurement can be used universally. Defining the units, realizing how they are used in practice and tracing the measurements made in practice to reference standards are the three core activities that metrology is concerned with. Metrology is the founding principal behind the International Standard of Units, also known as the SI system.
Metrology is Everywhere
One of the basics of metrology is that in order to intelligently communicate about everything from construction and manufactured goods to illness diagnosis and scientific experiments; there must be a single way to measure quantities. Imagine if you were to discuss the length of an object you had machined and described it as “two feet, three and one-eighth inches.” Since metrology encompasses continuous measurements that are valid around the world, most people would understand what you are saying. But if there were no uniformity, one person’s “feet” and “inches” could be far different from those of someone else. In fact, machining itself would be entirely impossible without the implied understanding of metrology. Attempting to explain any type of size range or the speed of your spindle would be impossible without having a unilateral base of what these measurements mean, as well as being able to communicate these basics to others.
Scientific or fundamental metrology develops measuring methods and establishing what units consist of. Being able to trace these units so that people can use them is among the barest basics of metrology, and is crucial to being able to calibrate any measuring device. One of the basics of metrology that you cannot escape using as a machinist is a length, which is quantified in both metric and US terms. As well, there is indentation hardness that you need to know for both your cutters and your material to be machined. Whether you use the Brinell, Rockwell, Shore or Vickers scales of hardness, this is among the basics of metrology you cannot avoid using to machine a piece of material accurately.
Without the ability to quantify and verify measurements, nothing could be produced in quantity, and modern production facilities could not exist. Technical metrology, also known as industrial metrology or just applied metrology, is concerned with the measurement of processes and how society uses the results of this production. Another part of the basics of metrology, this applied branch also deals with how suitable a measuring instrument is for the calibration of instruments and their quality control standards. Imagine that you are commissioned to machine a series of pieces that will go into a device. To do this properly, you must have and apply a set of measures and they must be consistent across your, your colleagues’ and your customers’ measurements.
Using your CNC machine effectively comes down to understanding its operation and getting any hindrances out of the way. With the mindset of constantly seeking better ways to solve problems, your CNC machine will be as effective as possible.
If you are a novice with your CNC machine, starting out with HSS (high speed steel) cutters is a wise move because they are less expensive but still of solid quality. Doing your best to find name brand cutters at a reasonable price will mean it will be less irritating when they inevitably break due to early mistakes. Once you have better proficiency and can zero the cutter heads easily, you can move on to carbide cutters. Using solid cutters, particularly as you get into finer sizes, will allow your CNC machine to make cleaner and more accurate cuts.
Your workholding setup is vital to the success of your CNC operation. Much of the work that goes on within the CNC machine is completely dependent on what happens outside of the device. The use of an effective clamping and vise kit to hold materials in place—for many machining requirements—and an understanding of where the material needs to move in order to be milled effectively are highly necessary. Also keeping a set of parallels to support the mass of larger pieces lets you mill effectively with less concerns about material movement. To use your CNC machine effectively, it is important to remember that a CNC machine is not merely working on a single cut, but holistically on a larger object.
Chips that get caught in the area to be cut can lead to rapid failure of your cutters. In some cases, this can be dangerous. Even in the best case scenario this can lead to dulling the cutting tools and making poor cuts on important and potentially expensive materials. The solution that makes your CNC machine work more effectively is to be extremely careful about chip management. This can be done, generally, by putting together a misting setup and applying the mist at angles that push the chips away from the cutting tool and its subsequent path.
Feeds and Speeds Calculator
Determining the effective spindle speeds and feedrate necessary for your cuts through “playing it by ear” are poor methods when using a CNC machine. Getting, and making a habit of using, a feeds and speeds calculator is very important. This will allow you to use your machine and your cutters optimally, minimizing wear-based damage caused by attempting to estimate a cut. This is also a better method when working with various materials, as they are less likely to be burred or otherwise damaged by improper cutting speeds or feed angles.
The use of honeycomb construction design has been in place for thousands of years, and continues to find new uses into the modern world. Through honeycomb construction design, you can produce a low-density and high-strength material for a variety of applications. The honeycomb derives its name from the hexagonal shape with which the walls of beehives are constructed, and has been used in different types of construction with increasing frequency over the past century.
The hexagonal shape of natural honeycomb construction design employed by hive-building insects was first observed in antiquity. In the year 36 BCE, Marcus Varro was credited with geometrically working out that hexagons are a highly efficient use of building materials and space. However, the practical use of hexagons was not until the re-construction of the Pantheon in Rome, where the dome was supported by a structure reminiscent of a layered hexagon shape. This increased the strength of the structure with only a minimal increase in weight, which lent greater stability to the design.
The modern version of the honeycomb construction design practice began to take shape during the industrial revolution. In 1638, Galileo discussed how hollow solid materials could be sturdy with a lower amount of weight than would be a solid piece of material. The honeycomb structure was further supported in 1665, when Robert Hook discovered that the cellular structure of cork has similar properties to the hexagons found in the honeycombs built by bees. This process became further vindicated in 1859, when Darwin stated that the honeycomb was a highly efficient economization of effort and wax. In 1877, F.H. Kustermann invented a molding process to make honeycombs out of a mixture of glue and paper. This was followed in 1890, when Julius Steigel invented a molding process for the repeating hexagonal shape for sheet metals.
Early 20th Century Applications
In 1901, Hans Heilbrun invented an expansion production-based paper honeycomb production process. The structural usage and honeycomb construction design process really took off in 1914, when R. Hofler and S. Renyi received a patent for the use of honeycombs as a structural element. Where the idea really took off was in 1915, with Hugo Junkers receiving a patent to use honeycomb cores on airplanes. In 1938, Norman de Bruyne patented the adhesive necessary to bond honeycombs together in airplane radomes. Boeing later used fire-resistant honeycombs extensively in the 747.
Since the 1980s, honeycomb construction design has become extensively used. With thermoplastic extruded honeycombs, tremendous strength at extremely low density is practical in large scale. The applications for honeycombs are all but limitless. Modern buildings sometimes employ aluminum wall cladding in a honeycomb pattern for aesthetics and strength. Honeycomb-based insulation is also used in some cases for a compact and sturdy method of building. Structures like the Honeycomb apartment complex in the Bahamas, Honey Bee Hive House in Israel and the Hivehaus modular home design from Britain use the honeycomb shape to its fullest. With advanced materials, the honeycomb construction design method has become even better than it used to be.
Milling large materials in CNC machines is a challenging task, but one you can do if you are careful. With the right cutter—understanding the power curve of your machine’s spindle and keeping access strategy in mind—large materials in CNC machines will be a challenge you can meet.
Use the Right Cutter
Using a higher-end cutter is very helpful for larger materials, particularly if they are of an especially dense or hard makeup. Better cutters allow for more precision, more control over your feed speeds, and the ability to process larger pieces without as much concern about the cutter burning out or having to overly reduce the speed. A better cutter is not the same as having a larger CNC machine, but for large materials in CNC machines of a smaller size this helps a lot.
Understand Your Machine’s Power Curve
Your spindle has only so much power, and keeping the movement of the piece to be machined within the power curve is important to avoid sticking points. For large materials in CNC machines that are either less powerful or smaller, keeping the power of your spindle in mind is important to effectively machining the piece and avoiding shape or finish-related mistakes.
Keep Access and Entry in Mind
The size of the piece is less important to consider if you mentally run through the operation to determine where the piece will enter and its travel path. Often, a larger piece can be fit through a smaller machine in much the same way as a long stick can be fit into a bag, simply by rearranging the path the piece will travel, including opening windows on the machine or even removing the enclosure altogether. So long as the piece is able to complete a given component of its milling, you can rearrange it along another unusual entry point, just so long as you can find effective access between the material and the cutter.
Remember All Three Dimensions
It is common, particularly among less experienced CNC operators, to forget about the Z axis. Ensuring effective clearance can mean rehoming your machine so the Z axis begins in a different place for mathematical ease. In some cases, significantly adjusting the angles of the piece is effective. Further, going to additional angles for multiple cuts may be an effective way to accommodate the larger height of the piece.