CARBIDE TOOL GRINDING MACHINES FOR ULTRA-PRECISE ROTARY TOOLS. Tool grinding machine

CARBIDE TOOL GRINDING MACHINES FOR ULTRA-PRECISE ROTARY TOOLS

When brittle, hard metal materials coalesce with relatively soft metals, primarily from the iron family (iron, cobalt, nickel); a material is created that is characterized by a high level of hardness as well as viscosity, known as carbide.

Its huge resistance to wear and capacity to withstand even massive physical loads make it a much sought-after material in many sectors: Including mechanical engineering, the automotive, steel or food industry.

Machining processes such as rotating, milling, drilling, engraving, sharpening and grinding are almost inconceivable without carbide. It is also used in non-cutting forming or for protection against wear. In the field of tool manufacturing, the hard metal is mainly used for indexable inserts, as solid carbide rods or in the form of precision tools like drills and milling cutters.

MACHINING CARBIDE TOOLS MORE EFFICIENTLY

For the most common sharpening process – grinding carbide – the correct grinding wheel granulation, adjusted grinding parameters and an optimum grinding pressure are vital parameters to guarantee maximum tool performance.

For significantly higher productivity during grinding without compromising on quality, VOLLMER’s “VGrind” precision tool grinding machine provides a solution which has immediately set new standards in tool manufacturing.

Thanks to innovative kinematics, which are controlled via two vertical spindles, various different milling and drilling tools can be produced quickly and precisely in large volumes.

VGrind 360S

The VGrind 360S – the new standard for the complete machining of rotationally symmetric solid carbide tools of up to 100 mm.

VGrind 340S

Grinding machine for the complete machining of carbide tools upwards of 0.3 mm in diameter

CNC Cutter Grinding In-House

As tooling complexity increases, one might expect in-house tool grinding to gradually fade away. In fact, though, more and more shops are taking advantage of CNC tool grinding’s increased capabilities to improve consistency, flexibility and productivity.

Advancements in tool grinding technology are allowing more shops to bring the job in-house for better flexibility and control of the production process.

The ANCA RX7sp micro tool grinder is designed specifically for small-diameter cutting tools that screw machine shops require.

An overhead support mechanism pushes the tool down into a V-block clamp to hold the tool steady and reduce vibration during the grinding process.

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Many factors have driven the rise of popularity of in-house tool grinding. The ability to financially justify the addition of a CNC tool grinder could be the biggest. Over time, the cost of CNC tool grinders has come down, particularly in relation to the number of features, the level of technology and the capabilities that are available. The ease of use of the software has also gotten much better, allowing a company that is not actually in the tool business to buy a tool grinding machine and support its own tooling needs. By manufacturing and/or resharpening its own tools, rather than relying on an outside source, a shop gets a firm grasp on control of its inventory, lead times and part quality.

Screw machine shops are no exception when it comes to trends toward increased use of in-house-generated tooling. These shops have a history of trying to maintain as much control as possible of all aspects of the business, including tooling requirements, but the limitations of manual tool grinding have often created obstacles to productivity advancements.

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The complexity of the tooling has grown continually as screw machines have become more flexible and more expectations have been put on the demand for the complexity of parts that they are producing. Getting the necessary forms for the tools, along with quality performance from the tools to provide consistent parts, has steadily grown more challenging with manual grinders.

While the challenges of more difficult parts have raised some issues, the knowledge of grinder operation may be the bigger issue. Screw machine shops are seeing a general aging of the employee base, where operators have a great deal of experience in getting good tooling off of a manual machine. This knowledge of the touch and feel of producing a quality tool is not easily handed down to new employees in a short time frame. On the other hand, training on a CNC grinder—operating the controls and making sure the program is correct—is more straightforward and tends to suit the interest of more people who are new in the business.

Finding A Solution

ANCA, supplier of a range of CNC tool and cutter grinders to meet large-scale manufacturing and entry-level production requirements, is addressing the needs of the screw machine shop with a line of CNC grinders targeted specifically for this market.

The RX7sp is a high-production machine for small parts (thus the “sp”). Specifically intended for grinding cutting tools with diameters as small as 0.02 inch (0.5 mm), the machine is designed to provide users the ability to expand their manufacturing and produce cutting tools for medical machining and other micro applications.

Schneeberger’s specialist tool grinding machines rely on FANUC controls and drives

Task: The Swiss toolmaker J. Schneeberger Maschinen AG produces a variety of tool grinding machines for a range of applications. To develop direct-drive machines, for instance, in which the workpiece oscillated at high frequency Schneeberger required a partner with expertise in drives and controls technology.

Solution: Schneeberger teamed up with FANUC, its supplier for drives and controls for many years. FANUC produces a range of linear drives that are ideally suited to this kind of application and supported Schneeberger in the development of the new technology.

Result: Equipped with FANUC CNC drive technology and a FANUC Series 31i-B5 CNC, the new machine features a HCC (High-speed Cycle Cutting) and enables precise and homogeneous machining routines.

Diversity in the tool grinding industry: a constant challenge for innovations

There is vast diversity in cutting tools for metal and woodworking: from small profile indexable inserts, right down to large broaching and hobbing tools. The different geometries, not to mention the materials on the workpiece and grinding disc side, present extreme demands on tool grinding machines used for production and re-sharpening. The machine manufacturer J. Schneeberger Maschinen AG, steeped in tradition and located in the Swiss town of Roggwil, regards this as a challenge, consistently responding with innovations.

And there is something new every year. For instance, two years ago at EMO, Schneeberger unveiled the NGM tap, which is suitable for production of threading tools in a single setup. It is equipped with a total of six axes, of which five are direct-drive. One of the special features of the NGM tap is that the workpiece can oscillate at a high frequency.

Dr. Hartmut Rühl, Head of Software and Electronics, explains: “Linear drives are ideal for oscillation. Because they enable these small, highly-dynamic movements, and in doing so, they are wear-free.” The direct-drive technology for Rapid oscillation already proved itself on the Gemini GHP grinding machine introduced ten years ago. The grinding disc oscillates on that machine, however, as it represents the smaller mass when grinding hob cutters. By contrast, on threading tools the grinding disc is often 300 mm in size and heavy. That is why Schneeberger decided to make the work piece oscillate.

With nine machines, such as the compact NGC, J. Schneeberger Maschinen AG provides for high efficiency in tool grinding. This is also thanks to components such as a proprietary, easily-integrated 3D probe that can be implemented in all Schneeberger machines. For many years, the trusted partner, FANUC, has stood by the Schneeberger technology engineers, providing assistance in drives and controls.

The development of direct-drive machines was supported by FANUC, Schneeberger’s supplier of many years for drives and controls technology.

This partnership with FANUC, which Hartmut Rühl believes in, has existed since 1990: “No other control manufacturer worldwide is so well organised. And the level of quality and reliability of FANUC products is extremely high indeed.”

CNC controls: Ideal for oscillating machining

At Schneeberger, there is no alternative to linear motors when it comes to oscillating movements. Hartmut Rühl explains in more detail: “We can achieve pendulum strokes of 5 mm with 15 Hz only with a direct drive. Whereby we program these movements not using G-Code, but rather via a data table. This is then converted into machine commands using a special FANUC software named HCC.”

With HCC (High-speed Cycle Cutting), which FANUC provides in the high-end CNC Series 30 i and 31 i CNC controls, precise and homogeneous machining routines can be achieved that are unattainable in any other process. The basic structure is straightforward: For each axis to be moved, a table is created, in which the relative movements of the particular axis are programmed for a defined time interval (e.g. 1 millisecond).

Tool grinding machines with small footprint and large work envelope

Last year, Schneeberger introduced with the NGC a universal and super compact new generation of tool grinding machines:

• It is suitable for standard tools such as face, radius and profile tooling cutters, high-performance borers, reamers, profile turning plates in HSS, carbide and Cermet.
• Specifically-designed software, grinding processes and clamping systems are available for the sharpening of hobs, shaper cutters, stick blades and bevel gear blades.
• Production grinding of blades for the paper, food or plastic industry is part of the range of capabilities, along with the machining of disc-shapedwork pieces with special clamping and automatic loading.

“There is a market demand for machines that have the smallest footprint possible, yet offer comparatively long traversing paths”, explains Hartmut Rühl. “With the NGC, we have achieved this balancing act.”

The compact 5-axis machine enables the complete machining of tools (circumference and face) up to a 300 mm cutting length. The workpiece can have a diameter of up to 300 mm and a maximum workpiece length of 500 mm. Although both the NGC and the NGM Tap are considered relatively small machines, Schneeberger offers them with grinding disc changers and seven disc packages.

Transition to a new generation of controls

For all machines in the higher-end segment, i.e. also for the NGM tap and the NGC, Schneeberger uses the FANUC Series 31 i.B5 CNC controllers ideal for 5-axis machining – in a version with an integrated ” Panel i ” industrial PC. This is linked to the CNC via the HSSB high-speed bus. It enables the grinding specialist to apply his expertise in the proprietary software Quinto with a customised interface.

All other machines from Schneeberger have also completed the transition to Model B, FANUC’s new generation of controllers. For more rudimentary applications in terms of programming, the previous Power Mate CNC has been replaced by the FANUC 35 i.B without PC support. Hartmut Rühl points out that the term “rudimentary” does not refer to the precision but to the programming requirements: “With these machines, hob cutters can be re-sharpened in 3A quality. A very demanding task indeed, requiring only ten out of 20 parameters, however, which can be completed locally on the machine.”

Controller specialist Rühl also indicates interest in the new FANUC compact CNC 0 i.F: “That would perhaps be an additional alternative for the lower-end segment of our grinding machines that have only a few axes and do not require a multi-channel capability.” With the 0 i.F, presented in Europe for the first time at the AMB 2014, the CNC world market leader unveiled its “Seamless Concept”. This states that all FANUC CNC drives and controls are built according to a unified standard and have comparable operating instructions. This means that both the 31 i.B5 and 0 i.F require the same peripheral components (amplifier, I/O etc.) and are included in the same housing. The software makes the sole difference.

D probe: Saving time through exact measurement in the machine

Schneeberger has yet another innovation that is offered throughout all machinery series and generations: its own 3D probe. Hartmut Rühl states the reason for this development: “Over time, the machines have become more and more precise and faster. So the integrated probe ought to have equal capabilities. In order to offer our customers the optimal solution, we developed a 3D probe that fulfils our requirements 100 percent.”

Accordingly, the Schneeberger Zenon probe is based on the use of semiconductor strain gauges (ScSG), a technology that promises a high level of precision. Application engineer Antonio Grasso, responsible for development, explains: “This measurement method is also used by the market leaders of tactile 3D measurement technology, and enables us to achieve absolutely comparable results.” This sensor technology achieves a high degree of repeatability which does not change even after several million probes. It also eliminates so-called “lobing”, which occurs with kinematic probes.

“When we use the Zenon on our linear motor machines”, Antonio Grasso explains, “which are renowned for an extremely rigid construction, we achieve levels of precision hardly surpassed by an external coordinate measuring machine. We have proven this in side-by-side measurements. Our precision is currently below one micron, and we are on our way to achieving reproducible measurements of 0.5 µm.”

Profiting from time savings

The user above all profits from time savings when deploying an integrated probe of this type. Because he can eliminate the need for retooling from measuring to re-setting the grinding machine. Every little bit counts, especially on large tools such as hob cutters or even granulate cutters, which may weigh up to a tonne. “For this, the setup can already take up to 30 minutes”, explains Hartmut Rühl.

From a quality assurance perspective, however, a probe integrated in the machine does not replace the measuring machine. Because if the setup was not correct, for example, you could not detect any fault with the integrated probe. But Antonio Grasso points out: “The user definitely benefits from the fact that he can assess his production process and verify reproducible results. Thus, it is perhaps sufficient for him to place only a few parts onto the measuring machine in order to verify absolute precision.

Controller function accelerates the probing process

Also in the development of the new probe, the application engineer worked closely with the drive and controller supplier, FANUC. As a result, the probe process itself has been accelerated. Because in the past, you had to traverse with the probe to the component at a constant speed. For this, it was necessary to keep a certain distance prior to each probe.

The new FANUC Model B generation of controllers now offers the ‘Feed Forward Compensation In Skip’ function, which also allows probing in the acceleration phase. “We are now achieving the same precision in a much shorter time”, sums up Grasso. “Because the FANUC CNC is a controller for machining and not a measurement controller that reads out the exact positions every millisecond, the result is remarkable. We have pioneered into a realm where we can partly compete with dedicated measuring machines.”

The good measuring results are not limited to the Schneeberger Sirius and NGN tap linear machines. Superior results were also achieved in trials with the NGC. What’s more, the Zenon probe is backward compatible. This means that if a user wishes to exchange his existing Schneeberger probe, he can easily do so with a small interface.

Pioneer of tool grinding

Already back in 1923, Walter Schneeberger established the company bearing his name. Two years later, he launched the R1 in the market, a tool-grinding machine with universal applications. In its technical pioneering role, the company developed and built the first CNC-controlled profile grinders in 1985. This ushered in the new era of tool quality. In 1990, Schneeberger launched the 5-axis grinding concept, and in 2003 the first machine with linear drives, the Sirius HPM.

Today’s product range of this 170-employee company also includes the Corvus, Gemini und Norma CNC grinding machines with outputs of up to 40 kW. In addition, with the Aries series, Schneeberger offers an economical alternative to 5-axis technology in re-sharpening. Along with headquarters in Roggwil, Switzerland, the company has subsidiaries in Germany, France, Italy, USA and China, as well as more than 20 agencies worldwide.

Tool and cutter grinding machine: 5 Filtration Systems That Can Ruin Your Grinder

Filtration systems are essential for your tool and cutter grinding machine. They help keep your machine running smoothly, which keeps your business running smoothly.

If you’re a cutting tool manufacturer, you know that the machines are expensive to buy and maintain. However, running these machines without proper filtration is even more costly!

In this article, we’ll go over 5 of the most common mistakes that can ruin your tool and cutter grinding machine.

Using no filtration at all with your tool and cutter grinding machine

The basic idea for a tool grinding machine is to use high-pressure oil. The oil keeps the cutting elements like the grinding wheel and blanks cool, so they do not overheat, fail, or deform. If you do not use grinding oil, there is excessive heat generation, and the cutting tool will never meet the quality parameters.

The oil inside the grinding zone must be filtered before it goes back into the machine tank. You need to filter your oil because it will contain tiny particles of carbide or HSS (high-speed steel). These particles cause significant damage to your tool and cutter grinding machine when they get mixed with oil. When this happens, your grinders and wheels will wear out much faster than expected, which means costly replacement and maintenance costs down the road!

Most tool and cutter machine manufacturers supply their machines with just an oil collection tank. The carbide/HSS-laden oil comes from the grinding zone, and the same black oil circulates back. Hence, cutting tool manufacturers need to be very vigilant and aware of this and plan to install an effective filtration system right at the beginning.

Every cutting tool manufacturer planning to invest in an expensive tool and cutter grinding machine needs to read this- 4 reasons to invest in a high-quality grinding oil filtration system.

Using a paper Band filtration system

A paper Band filtration system is an inferior way of filtering grinding oil. It is the worst and most ineffective method of filtration that you can use. Some might argue that it is better not to have any filtration system than to use a paper Band filtration system, especially for tool and cutter grinding applications. But why is that?

The carbide/HSS particles in grinding oil are minute. 80% are less than 10 microns. The paper Band filter design does not allow pressure build-up. Hence, there is no squeezing action while filtering.

Now, the tiniest opening on the filter paper might be less than 10 microns. However, that does not mean each pore on the paper is less than 10 microns. Hence, the filtration efficiency depends on the porosity of the paper.

The filtration efficiency one can expect from a paper Band system is 50 microns. Hence, the carbide/HSS particles pass through the filter paper and settle in the tank, or the pump picks them up with the oil and re-circulates them in the machine.

It’s not just about keeping the oil clean; it’s also about safety! Suppose you’re not using a high-quality filtration system. In that case, you’re risking having your machine fail at an inconvenient time—like when you grind special carbide tools for demanding applications like medical, aerospace, and defense.

• Oil remains black with carbide/HSS particles.
• The grinding wheel life deteriorates despite having a filtration
• Carbide is abrasive; hence if it remains in circulation, it settles on the machine bed and ball screws and damages them. Thus increasing maintenance costs of the machines and affecting accuracy.

Learn, how as a cutting tool manufacturer, you can explore opportunities in the aerospace sector?

Why is a bag filter system wrong for tool and grinding machines?

The bag filter is a better choice than the paper Band filter, but still a wrong choice overall. However, for this article’s purpose, let’s understand that the filter media used in these systems cannot generate enough resistance to trapping the carbide / HSS dust.

Cutting tool manufacturers use the bag filter system because they are cheap to operate, but they also cause many issues. Bags cannot generate enough resistance for trapping the carbide / HSS dust; therefore, they need regular cleaning (which can become very time-consuming).

Hence, it is twice the punishment for manufacturers who use bag filters for filtering carbide or HSS particles. Firstly, the bag does not filter oil down to the desired level. Secondly, the bags are consumable. Importantly, carbide starts to choke the bag pores, reducing the rated oil flow through the bags. At this point, there is no option but to replace them.

Do you know how carbide leaching affects the life of your cutting tools?

Are cartridge filters better compared to bag filters?

1-micron filter cartridges are indeed good at removing carbide particles from grinding oil, but there are a few things you need to know about them.

First, dirt load in tool and cutter grinding machines is high, leading to higher cartridge consumption. over, it would be best to discard these oil-soaked paper cartridges appropriately.

Frequent cartridge changes are expensive for your business over time because you will have to replace them frequently. over, spend money to discard them properly.

For example: If you use a 1-micron cartridge on a machine that runs 24 hours per day, seven days a week, and only changes the filter once every eight days (typical), then your costs will be much higher than with a 5-micron cartridge.

Curious about Industry 4.0? Learn how cutting tool manufacturers can be Industry 4.0 ready.

Filtration system for carbide recovery from your tool and cutter grinding machine

Carbide recovery is another important consideration when choosing an oil filtration system for your tool and cutter grinding machine. Because carbide scrap is so valuable, getting all the carbide out of your used oil makes sense.

But many conventional filter systems can’t do that. Paper Band filters, for example, don’t separate the carbide from the rest of the oil—so it gets discarded along with the media. The same goes for cartridge filters, which consist of multiple layers of different materials that can trap fine particles inside them.

The only way to get every bit of carbide out of your used oil is with a Transor India filtration system. Transor India filters capture even fractions of microns—less than one-millionth of a meter!

If you want to invest in a high-quality, long-lasting filtration system that will recover carbide and help you grind the best cutting tools, speak with our experts. Please click here to contact us.

Using a centrifuge to filter out carbide/HSS

Centrifuges are not a good option if you’re trying to filter out carbide and HSS from your grinding oil.

You see, centrifuges are not filters. They don’t use filter media to remove the solid particles from a fluid—they use centrifugal force to separate the particles.

So if you’re trying to filter out 1-micron particles from the grinding oil using a centrifuge system, it won’t work. You’ll end up with clear oil still full of carbide and HSS!

But if you want to recover carbide? A centrifuge is your best bet. They work like a kidney: dirty oil comes in, and clarified oil goes back into the same tank. That way, you can check how clean your tank’s oil is—and if it’s black or blackish (which means there’s carbide or HSS), then you know what needs to change.

Finally, we must mention one more thing: a centrifuge adds heat as it spins. So if your application is temperature-sensitive, which most carbide cutting tool grinding is, be careful when using this method!

As a cutting tool manufacturer, you may be interested in our article-

How can cutting tool manufacturers plan their investment?

We understand that the cutting tool business is very competitive. Manufacturers follow the above-mentioned wrong practices to save on initial investments.

However, each manufacturer has to think about the trade-off between saving money by cutting corners initially and paying a higher price for maintenance and low quality later. If anybody you know and care about uses one of the above systems with their tool and cutter grinding machines, please share this article with them to make them aware!

In conclusion, we would like to say that there are many other ways to improve the performance of your grinding machine without breaking your bank account. We hope this article has provided valuable information for those looking to optimize their grinding processes without spending too much money on equipment or upgrades! The key is to invest in high-quality accessories from reputable manufacturers.