Coolant systems rarely get top billing as the bar peeling inserts key feature of a machine tool, but that is the case with the lathes and machining centers being introduced to this country by Hakusui USA Inc. (Schaumburg, Illinois). The line of machine tools includes four lathe models and two vertical machining centers. All of the machines have, as a standard feature, a high pressure mist coolant delivery system that creates a mist of ultra-fine water and oil particles. The company claims that this allows for significant increases in surface speed and metal removal rates and longer tool life.

This method of coolant delivery, which the company has dubbed the ECOREG System, mixes a water-based coolant with an oil lubricant in a high pressure air stream, creating extremely small particles. These particles are then injected through high-pressure nozzles designed to be precisely directed to the point of machining.

The coolant is a solution of an anti-corrosive agent and surfactants diluted in water. The ratio of water and solution varies from 20:1 to 30:1. The oil lubricant that the company recommends is a specially formulated vegetable oil but other oils can be used, with those formulated as extreme pressure lubricants being recommended. The advantage of the vegetable oil is that it creates virtually no environmental impact.

One of the main benefits of the system is that is uses very little liquid. The company says that, under typical machining conditions, its lathes consume about one liter of coolant in 55 hours of machining. The VMCs consume approximately the same amount under normal machining conditions. Despite this low usage, the system provides a substantial cooling and lubricating effect.

This effect is apparently due to the almost immediate evaporation of the mist on contact with the workpiece, cutting tool and chip. The misting of the liquid increases its surface area, enhancing its capacity to absorb heat. Pinpoint aim of the nozzle is critical however, because the high pressure delivery of the mist blows away chips, which carry off much of the heat generated in machining. High feed rates and spindle speeds, of course, help considerably to keep heat in the chips as they are formed. Because almost all of the mist evaporates so quickly, the chips are dry, aiding their disposal and increasing their value as a recyclable material.

The fine particles in the mist also allow it to penetrate the cutting tool/workpiece interface when injected at high pressure. Apparently, the ECOREG System creates particles that are small enough to enter the gap between tool and workpiece while high pressure overcomes the centrifugal force of the rotating tool or workpiece. Thus, a very small amount of the oil lubricant—0.3 to 0.5 cubic centimeters per minute—can be very effective, the company says.

In addition to the environmental benefits of this system, the company also cites improved machining results. The combination of increased speeds and feeds with the effects of high cooling and excellent lubrication results in better dimensional accuracy of the workpiece, finer surface finish, higher productivity and increased tool life. The company has not published direct comparisons for various applications but is inviting users to submit sample workpieces for testing at the company’s technical center in Schaumburg. The company will then report on process improvements to be expected using its machine tools at the recommended settings. An increase in tool life as high as 400 percent is cited in the company’s literature as a typical benefit.

Otherwise, the lathes and VMCs to which Hakusui is attaching its ECOREG System are of conventional design. The lathe line includes two 6-inch models, an 8-inch and a 10-inch model. The HL-06 lathe, for example, features 1,181 ipm rapid traverse in X and Z axes, with an optional 6,000 rpm spindle. For this model, the company has published a case history involving a 2.25-inch bar of 303 stainless steel machined with a carbide insert at a depth of cut of 0.04 inch and feed rate of 0.004 inch. With a spindle speed of 2,800 rpm and surface speed 1,680 fpm, resulting surface gun drilling inserts roughness is given as 0.00006 inch and circularity is given as 0.000031 inch TIR. In another example, the HTL-80, an 8-inch lathe, performed a rough cut on 1046 steel with an 0.08 inch DOC at 1,640 sfm producing a 3.4 micron surface finish. This operation consumed a half ounce of coolant per hour.

The two VMCs in the line are both designated as 40-inch models. The HV-40 is slightly smaller, with 30 by 17.7 by 19.7 inch axis travel and 7.5 hp compared to the HTV-40 with 40 by 20 by 20 inch travel and 10 hp. Both models have optional spindles, with an HTV-1000 model offering 10,000 rpm. All of the Hakusui lathes and VMCs are equipped with Fanuc controls.

The ECOREG System is also available as a stand-alone unit, model MRC21, which can be retrofit to existing machine tools.

The Carbide Inserts Website: https://www.cuttinginsert.com/pro_cat/helical-milling-inserts/index.html

This blog post is adapted from an article by Barry Rogers which appeared in the May edition of the Machine/Shop print supplement to Modern Machine Shop.

In the first part of this blog post series on buying a horizontal machining center, we covered some of the structural, application and design factors that differentiate HMCs from vertical machines. In this post, let’s look at tooling- and workholding-related concerns that those interested in acquiring an HMC will want to keep in mind.

All modern HMCs are built with indexing tables and are considered four-axis machines. Assuming you’ll be using a tombstone with parts on each side (which is how almost all HMCs are set up in machine shops), you can perform operations not only across the front, but also from the right and left sides of the part. For example, a valve body with holes on the sides can DNMG Insert be machined in one setup.

Basic HMC tables are indexable, meaning that the table can turn and lock in 1-degree increments only. The part can be turned, say 20 degrees, cut at that angle, or perform other operations such as facing a surface at an odd angle, milling a pocket, or drilling/tapping a hole. Odd angles that require complex setups and fixtures on a VMC become easy to program when machined on an HMC.

HMCs can also be ordered with a “full fourth axis” that will move to any angle, say 11.5 degrees, under programmed command and enable cutting while the table rotates simultaneously. Indexing tables are not capable of cutting odd angles or cutting while the table rotates. In fact, indexing tables have another disadvantage compared to a full fourth axis in that indexing tables are considerably slower. To index the table, the spindle must first retract the cutting tool; the table must then unclamp, rotate to the desired angle or location, then re-clamp. These steps lengthen the machining cycle. However, full-fourth-axis tables also have a disadvantage. They’re expensive. The deciding factor is the required process.

A standard feature of most HMCs is a 40- or 60-pocket automatic toolchanger (ATC). The simplest type of ATC has a dedicated pocket for each tool. Changing tools will take longer with this type of ATC than other types because it must put the tool back into the same pocket after each use. In contrast, a random-access toolchanger, often called a matrix magazine, can retrieve a tool and return it to any pocket, because the controller keeps track of each tool location. Tool changes are quicker.

Some workpieces may require more than 60 tools to complete the job. Here’s when much thought and planning are necessary prior to purchasing a machine. To determine required toolchanger capacity, find tooling commonalities across the full range of workpieces intended for the HMC. Use standardized tooling to make best use of all available tool pockets in any ATC. Redundant or sister tooling may also be added to help keep the spindle running for longer periods.

Moveable pallets that sit on the indexing table or fourth axis can be used to secure the associated fixtures and parts for machining. These pallets can be moved in and out of the workzone with an automatic pallet changer (APC). The APC is essentially a rotating carrier with two sides separated by a panel. The pallet is rotated to face the machining zone and lifted onto the table so the parts it holds can be machined, while the pallet on the other side of the panel can be handled outside the workzone. By continuously exchanging pallets, the APC can keep the HMC running with little time between pallet changes. Ninety percent of all horizontals come with an APC

Tombstones are upright fixture blocks with two or more sides onto which parts can be mounted for machining. They are also known as pedestal-type fixtures, tooling towers or tooling columns. These fixture blocks can be configured with two, three, four or six sides. The basic idea of a tombstone is to hold multiple parts per side. Typically, tombstones are made from aluminum or cast iron, and have bolt holes for attaching fixtures and clamps to hold the parts. The tombstone can be mounted on a moveable pallet to be shuttled in and out of the machine.

Single-sided angle plates can also be mounted on an HMC, with or without the use of a tombstone, to machine parts made from flat plate.

With an HMC, you have to be more creative when it comes to fixture designs. Fixtures may require more sophistication than those for a VMC, depending on part size. While it’s often easy to get by with using vises on a VMC, vises are less useful on a horizontal. Common tooling items used on HMC fixturing include edge clamps, toe clamps and wedge clamps. While fixturing on an HMC might seem complicated, it also provides considerable flexibility. HMCs can use hydraulic or pneumatic fixturing. Some machines have the option to plumb hydraulic or pneumatic lines through the pallet which can then be incorporated into the fixturing. M codes are used in the CNC program to apply clamping pressure into fixtures in the machining zone. Although you can do the same on a VMC, it’s more convenient on an HMC, because the pallet can be shuttled to the unload station while the clamps are still engaged. Hydraulic and pneumatic lines are usually fixed on a VMC, but on a horizontal, the lines are usually integrated in the pallet. This feature gives you the ability to use multiple hydraulic or pneumatic fixtures across multiple pallets without having to remove and replace hydraulic lines or fittings.

Pallet pools enable more than two pallets to be used for continuous operation. Without a pallet pool, there are only two pallets and they must run one after the other. A pallet pool interfaces directly to the APC, enabling a pallet to run in any order you decide. For example, if you have four different jobs lined up on the machine and one job runs out of material, production of the other three can continue.

Typically, pallet pools consist of six or more pallets, making around-the-clock, lights-out operation possible. Even if you buy an HMC with no intention of running all night, you still gain savings by automatic loading and unloading without interrupting the spindle of the machine. The uptime created by this method accounts for increased spindle utilization, which can be as high as 85 percent.

Compare machine specs from thousands of horizontal machining centers for free at techspex.com.

Find more insights about acquiring a new machining center by visiting the Techspex Knowledge Center, “Guide to Buying Machine APMT Insert Tools.”

The Carbide Inserts Website: https://www.estoolcarbide.com/product/scgt-aluminum-inserts-p-1218/

As a supplier of metal-removal tooling for more than 100 years, Ingersoll Cutting Tool Company (Rockford, Illinois) has sought to help manufacturers remain competitive by providing innovative and productive metal-removal solutions. Since the early RCGT Insert 1990s, the company has used Vericut software from CGTech (Irvine, California) as a component of its manufacturing process.

“We have had Vericut in production for so long, I think that it is taken for granted,” says Paul Gerardy, systems engineer. “With our shop primarily running five-axis programs, machine crashes were a factor in our decision to implement the software. It keeps the spindles in the shop turning. Now, we rarely have crashes, and we no longer provide setup pieces for NC program prove-out.”

The NC programmers at Ingersoll also rely on the simulation software to prevent mistakes when programming complex, five-axis parts. The verification software that simulates from post-processed code allows the user to detect errors before they happen on the shop floor. Many CAD/CAM systems output program data as an APT/CL translator program or in ASCII neutral format. This data defines the principal tool path, speeds and feed rates as a machine tool-independent generic NC program. The post-processor receives this file and converts it to the specific machine tool instructions required to control the axis motion, tool changes, cutter compensation, coolant pumps and more. Unless discovered by the independent verification software, errors that are introduced at this stage will go undetected until a machine crash occurs or during a manual prove-out run, the company says.

Vericut can prove-out the machine and post-processor before they arrive in the shop. “We try to have the programming process for a new machine setup before the machine tool hits the floor,” Mr. Gerardy says.

The capability to simulate NC programs from post-processed code became critical when the company was forced to change CAM systems from a mainframe-based APT system to Pro/NC. The time frame for the transition was tight, because the company had just 3 months before it would lose access to the mainframe. Because the software was independent from the CAM system or post-processor, it facilitated a smooth transition.

“It was like Y2K all over again, except we knew exactly what we were up against,” says Mr. Gerardy. “Not only did we lose our CAM system, but we also lost all of our post-processors. After that, we purchased ICAM to post-process Pro/NC CL data. It was nice to have at least one component of the NC programming process that we could count on. You could say that the software was a firewall between the office and the shop, and it smoothed out the transition to Pro/NC.”

The software is a key part of the company’s tool assembly building routine. Ingersoll does not use pre-defined tool assemblies, but rather, it relies on the software to determine the minimum extension length for each tool assembly. That information, along with minimum and maximum gage-length information that is output from the post-processor, enables the company to select the most rigid tool assembly for the job.

“The machine operators are confident about this method because they know the tool assembly we specify will not cause a collision,” says Mr. Gerardy. “As a systems engineer, I like the ease with which I am able to configure the software for automation. We like to automate everything we can for the NC programming group. Vericut allows us to do just that.”

According to the company, the capability to automate the verification process is crucial because the company’s NC programmers create numerous programs per day. So it is imperative that the software is not a cumbersome part of the process.

A small reduction in machining time can translate to substantial savings over the course of a single production run, the company adds. Mr. Gerardy and System Engineer Pete Risley implemented the NC program optimization software into their manufacturing processes. As a result, every NC program sent to the shop is first optimized using the OptiPath module. Consequently, a few extra minutes spent early in the programming stage can save time at the machine.

OptiPath works by analyzing either the post-processed NC program (G-codes) or the direct CAM system output. It then divides the tool motion into smaller segments determined by user-defined settings in the software. By analyzing the amount of material removed in each segment, the software assigns the ideal feed rate for each cutting condition encountered, says the manufacturer. It then outputs a new NC program, which is identical to the original one but features improved feed rate settings. The software does not alter the toolpath trajectory.

“When we first implemented the module, our operators were skeptical,” says Mr. Gerardy. “However, it wasn’t long before the operators were calling the NC programmers and telling them when they forgot to optimize the tape. Our NC programming group pumps out a lot of programs every year. We have implemented OptiPath in such a way that it only adds a few minutes to their programming process, if anything.”

Even though the optimization process may seem like an extra step, it can simplify programming.

“With OptiPath, the programmers do not have to be quite as picky about inefficient portions of the tool path because the Carbide Milling Inserts module will take care of it,” Mr. Gerardy says.

In addition to more efficient feed rates, optimized NC programs typically result in parts with better surface finishes, the manufacturer says. Additionally, the optimized programs are said to produce constant chip load. Therefore, tools may last longer, and machines can run smoother.

“It seems like the more complicated jobs are the ones that we really see big savings,” Mr. Gerardy adds. “When we first implemented OptiPath, we had the NC programmers record time savings for every job that they processed for about a year.”

The Carbide Inserts Website: https://www.estoolcarbide.com/product/ccgt-carbide-turning-tool-inserts-for-machining-aluminum-p-1215/

Faced with increasing SNMG Insert competition from low-cost, overseas manufacturers, mold industry shops continually seek to reduce costs wherever possible. However, according to cutting tool manufacturer OSG Tap & Die (Glendale Heights, Illinois), overlooking the advantages of high-performance equipment in favor of lower-cost solutions is often a mistake.

One company that recently benefitted from looking beyond the price tag is Melrose Mold & Machining Co. While the shop could have saved money up-front by investing in inexpensive cutting tools, it chose instead to go with higher-performance models from OSG. The resulting improvements in tool life and throughput more than made up for the tools’ relatively higher initial cost, demonstrating that tool prices do not necessarily correlate directly with the overall cost of producing a part. In fact, the new tools reduced overall machining time on one mold by almost 95 percent.

Based in Franklin Park, Illinois, Melrose has been building precision molds for rubber products for more than 35 years. Recently, pressure from offshore competitors led company president Mark Kawczynski to consult with Darije Nikolic, president of Elmurst, Illinois-based tool supplier Abrasives Inc., to seek a solution. Mr. Nikolic quickly realized that what Melrose needed was not the lowest tooling price, but rather tools that could provide the best value in terms of cost per hole and cost per cut.

Having worked with OSG for many years, Mr. Nikolic trusted that the exclusive metallurgy, geometries and surface treatments common to that company’s line of tools could provide long-term cost savings at Melrose. One of the first projects to employ the tools at Melrose confirmed his predictions. That particular job involved a 20-cavity mold made of 4140 prehardened steel that required expedited delivery. Based on the prototype, the shop had calculated that the mold would require 170 hours to complete—an unacceptable timeframe.

Mr. Nikolic recognized that the first step to increasing efficiency was to address 3D roughing, the most time-consuming portion of the process. Instead of a conventional indexable milling cutter or solid carbide end mill, he recommended a high-feed OSG Phoenix indexable radius cutter to increase the metal removal rate. “The Phoenix can cut what was until now considered the work of ball end mills,” says OSG district manager Stevel Lauman, who worked closely with Mr. Nikolic in offering solutions to Melrose. “Its tool form is designed to increase removal rates and take stepovers similar to ball mills while maintaining the rigidity of a radius end mill.”

The tool enabled Melrose to double the cutting depth to 0.59 inch while increasing spindle speed to 758 rpm. Feed rate remained constant at 62 ipm. As a result, the roughing portion of the job was cut in half. Moreover, after roughing, the part’s finish was sufficient to practically bypass the semi-finish stage and go straight to the finishing part of the job.

To bring the core and cavities to final finish, Mr. Nikolic recommended OSG’s Exocarb-WXS, a high-feed, solid carbide bullnose radius end mill. Compared to the shop’s previous finishing tool, the proprietary WXS coating provided a higher oxidation point, harder tool surface and lower coefficient of friction. In the first finishing pass, which called for a 1/2-inch version of the tool, these features enabled the shop to reach a feed and speed of 3,250 rpm and 357 ipm at a 0.2-inch cutting depth. In the following operation, with a 1/4-inch WXS mill, the shop achieved 6,500 rpm and 357 ipm. To finish off the mold, Melrose employed a 3/32-inch, four-flute square version of the tool, which ran at 7,500 rpm and 28 ipm.

The shop had originally estimated that the new tools would cost 30 percent more than the models it typically employed. However, that ceased to be a concern when employing those tools cut production time from 170 hours to 9 hours—a 94.7-percent reduction. The largest time savings came from the semi-finishing and finishing stages. During roughing, the Phoenix mill created a relatively TCMT Insert smooth surface with low scallops that enabled the WXS end mill to run at more than 300 ipm, significantly reducing machining time in the finishing stages. Moreover, machining time alone wasn’t the only driver of cost savings. The various Exocarb tools used in the first project still had ample tool life left to apply on the next job, a 10-cavity mold.

Although high-performance tools can cost as much as two or three times more than conventional, general-purpose cutters, they can also provide greater value by minimizing machine time and labor with faster speeds and increased throughput. Even more importantly for a shop like Melrose, such tools impact the ability to meet customer needs for quality, pricing and delivery in a demanding market characterized by low-cost, foreign competition.

The Carbide Inserts Website: https://www.estoolcarbide.com/

It’s not just about the cutter. As a matter of fact, it’s not just about the spindle speed or machine tool, either. Selecting the most appropriate tool to maximize high speed milling applications requires a balanced approach that takes many considerations into account. Chief among them are workpiece material, part configuration, types and sizes of cuts required, machine rigidity, torque availability, toolholder balance, and safety.

High speed milling in itself is but a means to an end. Tim Marshall, product manager, and T.J. Long, standard milling product engineer, at Kennametal Inc. (Latrobe, Pennsylvania) prefer the perspective of maximum metal removal. "Machines can offer up to 30,000 rpm and higher in spindle speed, but, to take advantage of today’s high speed milling tools, the machine tool’s horsepower/torque curve needs to be considered," Mr. Marshall explains. "Combining the machine tool’s peak operating range with current technology of high speed milling tools allows you to deliver maximum metal removal rate. Maximum metal removal is where the money is. Anyone considering high speed milling needs to understand this."

Such a statement holds equally true for high-volume, high-production operations or in producing small- or single-lot sizes. In high-volume operations, saving seconds can translate into sizeable cost reductions. In small-lot or one-off production, such as in the die/mold businesses, improved surface finishes and true 90-degree cuts can obviate the need for subsequent grinding or polishing operations, enhancing quick turnaround or just-in-time delivery.

One of the first considerations a user needs to take into account is the surface speed range for the tools in the selected workpiece material. "Hitting 20,000 rpm on a 5-inch cutter is vastly different than on a 1-inch cutter," Mr. Marshall points out. The tooling suppliers’ speed recommendations must be followed to assure proper tool life (sfm=cutter diameter x rpm x 0.262), adds Mr. Long.

Balance can also make a difference in high speed milling performance and results. "As a rule of thumb, it’s good to be aware of balance considerations anywhere above 8,000 rpm," Mr. Long explains. That’s because balanced toolholders make a demonstrable difference in improving surface finish and in the wear characteristics that affect tool life. Some tools, such as slotting cutters, are not balanceable by design. Others, such as end mills with integral shanks, are. For example, Kennametal’s Mill1 Max, its newest tooling for high speed, high-feed aluminum milling, are pre-balanced to a specification of G2.5 at 10,000 rpm in integral shank (monoblock) slot milling cutters tools, and they are balanceable to higher specifications, if required.

"With higher balancing specifications, every time an insert is changed, the tool may need to be rebalanced," Mr. Long advises. "If shops don’t have access to balancing equipment of their own, a supplier like Kennametal can do it. For the highest security at high spindle speeds, users should replace insert screws every time they index an insert and make sure they’re tightened to the correct torque specification."

Safety is also a paramount consideration, particularly with high speed machining. "Anything coming loose at even 8,000 rpm is a projectile," Mr. Long says. "Essentially, any windows, doors or shrouds on a machine tool need to be bulletproof."

Selecting tooling for optimizing high speed milling Lathe Inserts applications equates to a decision to maximize a company’s milling productivity and reduce manufacturing costs. Speeds (sfm) and feeds make a big difference, as does achieving maximum metal removal (MMR). Additionally, as with many production decisions, there is a guiding formula, according to Mr. Long: MMR equals the number of inserts multiplied by axial depth of cut times radial width of cut times chip load times rpm.

"Operating the machine at the rpm where you can achieve the highest MRR provides users the greatest benefits," says Mr. Marshall. "Calculate the results and use a machine tool’s highest horsepower/torque rating, and you’ll be on your way to achieving the higher feed rates and maximum efficiencies tooling such as Mill1 Max offers."

The Carbide Inserts Website: https://www.estoolcarbide.com/product/npht-npmt-bta-insert-coating-alloy-deep-hole-drilling-insert-p-1173/