This leads to fewer tools needed in the turret but also fewer tools needed in your tool crib. The multifunctional nature of these tools also eliminates tool changes, so cycle time is affected as well.

Here’s the math: Each insert has ten edges, yielding about 100 pieces apiece.  A new set of three inserts, good for the next 100 pieces, costs much less than a single solid-carbide mill that goes dull after only one.

Another option for multidirectional tooling is purchasing the tool and augmenting your G-code program.

The demo was so convincing that Glasper standardized on the corkscrew process within two weeks.  “I’d never seen a hole roughed out from solid that fast in my life,” he said.

Multidirectional turning tools can work in both directions (away from and toward the chuck) and perform roughing and finishing (with the top and bottom of the insert) with a single tool. They also perform multiple turning operations like profiling and facing.

“For example, a CNMG 120408 may commonly run a 3 mm depth of cut in the range of 0.4 mm per revolution (MPR) feed rate whereas the Prime B insert has the capability of reaching 0.75 to 0.95 MPR feed rate at that same depth of cut. Of course, horsepower and quality of setup play a very large role in the overall success of the application,” said Brake. “It’s a combination of the way the program is created to properly enter the workpiece, and the way the inserts are designed. It’s just physics. We are leveraging physics to thin the chip with a shallow entering angle.”

“The other major difference is that this insert is held differently,” said Gill. “This insert is held by a top clamp, but it also includes a rail design. When you are cutting at a higher feed rate, you now have much more effective clamping.”

By switching from orbital milling to corkscrew milling with an indexable, Ingersoll Cutting ToolsHi-Feed Deka face mill for holes over 1.500 inches, Baldor has cut the process cycle time by an average of three to one, and improved tool life by 10 to one. Then, a boring sequence finishes the holes, as before.  The annualized saving from the process change at Baldor Gainesville is estimated at more than $40,000 annually.

It’s easy to wrap your head around the fact that cubic inches of material removed per hour is the gold standard of metrics. However, many other factors play a role in the success of a machine operation. Some of them will contribute more than others, but they all help. These tools can stack benefits.

This leads to both better machine utilization, because fewer tool changes are needed, and faster cycle times. It starts with the tool itself and is aided by advanced programming, unique insert geometry, and machine movement.

CoroPlus Tool Path is a cloud-based software that can be purchased by annual subscription. This software allows feature-based programming of CoroTurn Prime tooling. Other systems capable of creating similar code for CoroTurn Prime tools include Gibbscam, Mastercam, Siemens NX, CamWorks, and TopSolid.

“This insert, although it's a triangular-shape insert, has 12 cutting edges instead of six that you would expect from a TNMG-style insert because you can cut from each side of each cutting edge,” said Gill. “When you are push turning and pull turning, you're using different sides of the insert, effectively increasing tool life.”

“We do understand that most people have already made an investment in a large CAM package, and that’s why Sandvik Coromant has partnered with CAM providers to program CoroTurn Prime inside of their systems,” said Brake.

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“Because of the workpiece geometry, the holes must be drilled from solid in a long-reach setup,” Glasper said.  “Not only was it slow going with the orbiting method and the solid-carbide too: we also went through a lot of tools.”  Moreover, he recalled that operators were concerned because the spindle load meter read 90% even at that slow rate.

The advice from Gill is to roll-in to the workpiece when entering the cut and feed the tool at 0.008 in. per revolution (IPR). When turning away from the main chuck, the cutting edge’s contact with the workpiece becomes larger, generating a pull greater cutting force, as compared to a push force when turning towards the chuck. He also advises that tailstock support should be used.

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The idea of plunging vertically into thick solid metal requires a leap of faith.  In another Georgia operation, a small job shop, the owner saw a demo of the process on guide pin holes in wrought tool steel die sets.  He bought the tool on the spot and jotted down the field engineer’s recommended parameters.  Then, he ran it in scrap wood for weeks and weeks before working up enough courage to run it on a real workpiece.  Once he finally got running, hole-making time dropped by eight to one.

He added that the combination of high-feed insert geometry and fewer flutes achieves much higher chip loads.  “The 1.5-inch indexable Hi-Feed Deka face mill can withstand feed rates of 0.015- 0.040 inches per tooth, versus 0.002-0.006 for a 3/4-inch solid carbide mill, Dieken continues.  “And, with fewer flutes, there is more room for the chips that come off so much faster.”

Another option is the 3C-TCMT, a single-sided, three-corner insert. It also enables higher feeds during pull turning when compared to ISO tools and also performs push turning.

“The front of the insert is like a regular CNMG insert with 80-degree angle and five degrees of clearance. It behaves like a regular CNMG insert because it has the same shape as that type of insert,” said Gill.

The switch got its start early in 2010 when Darimus Glasper, manufacturing engineering technician at Gainesville, started looking around for a faster way to open three-inch holes in a ductile iron casting with two-inch thick walls.  The part is an explosion-proof cover that encloses the electrical leads in large motors.  Baldor Gainesville’s annual production volume is 100 of these pieces, performed intermittently in 10-piece lots.

Sandvik Coromant’s B-type inserts are double-sided negative inserts with four cutting edges (eight total edges) designed for roughing and finishing. Sandvik Coromant

“Second, the indexable tool has twice the diameter as the solid-carbide mill and it has a steel cutter body,” he continued. “This makes it much better able to withstand the lateral forces involved inherent in the process at those high MRRs.  Moreover, the 70-degree lead angle helps mitigate the impact and lateral forces at entry.”

When used properly, it can perform both roughing and finishing applications without changing the tool. This feature helps to reduce carbide usage and conserves turret real estate.

Multidirectional turning tools (a.k.a. all-directional tools) have been around for a few years now. As more tooling suppliers enter the space, it’s important to get an understanding of how these tools can help you turn parts better. And it all starts where the carbide meets the metal.

The tool families of 6C-TOMG and 6V-TOMG are double-sided, six-corner inserts with 80-degree or 35-degree corner angles. For pull turning, they can be used at high feeds to improve productivity by roughly 200 per cent when compared to traditional turning ISO tools. The same tool also performs push turning using the same cutting edge angle as standard ISO tools.

Tungaloy has two tools in this space, if you don’t include its multidirectional Y-axis insert. One mimics a traditional CNMG insert, and one mimics a VNMG insert for undercuts and profiles.

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The change also removed a wild card, added Chris Pope.  “Because most holes at Gainesville measure less than three inches and the 1.5-inch tool covers more than half the diameter, there is no slug to upset things.  All the metal exits as chips.”  (Since he led the process change at the Gainesville plant, Pope has joined Gamco Services, Inc. Baldor’s principal integrated supplier.)

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Multidirectional tooling improves machine utilization, because fewer tool changes are needed, and enables faster cycle times. Tungaloy Canada

“It should maybe be thought about as two different tools, one to rough and one to finish,” said Gill. “In this case, you're using this backside as a roughing edge and the frontside as a finishing edge. This reduces the number of tools you need.”

The system can perform traditional facing and turning paths, like a CNMG 432 insert (end forward and side forward turning). Additionally, it can also perform side backward or face backward turning when engaged on the high productivity or chip thinning side.

Over the following several months, as orders came in, Glasper applied the same corkscrew million process to other, smaller-volume workpieces.  Today, Baldor-Gainesville uses the method on several different jobs that require holes of 1.500 inches, and larger.  Many of these projects involve odd diameters, for which standard twist drills are hard to find.

“If you’re currently running a CNMG insert with 3-mm depth of cut or less, you can use this system in an existing program. Nothing has to change, and you can get the benefit of chip control that these insert geometries offer,” said Brake. “This can be very important for customers who are running P1 or long-chipping steel. It’s a really simple way to gain chip control if properly applied.”

Re-engineering the process was not a simple drop-in tool replacement.  It involved reprogramming toolpaths and machine parameters as well as re-plumbing the machine to provide through-spindle flood coolant for chip clearance.  Pope and Ingersoll southeast manager Phillip Johnson assisted with the parameter setting.

Increasing your material removal rate. Reducing the number of tool changes. Lowering cycle times. Creating a 90-degree shoulder. Profiling and facing with one tool. Roughing and finishing with one tool. Does any of this sound good to you?

Sandvik Coromant’s multidirectional platform, CoroTurn Prime, is more than just a tool and insert. CoroTurn Prime comprises specific tooling and software that allow for higher material removal rates, longer tool life, and better machine utilization, according to the company. CoroTurn Prime is a family of multidirectional turning tools that have a combination of small entering angles and over and under coolant capability. Currently, the company offers two types of CoroTurn Prime tools: A-type and B-type inserts. A-type inserts have three corners designed for light roughing, finishing, and profiling. B-type inserts are double-sided negative inserts with four cutting edges (eight total edges) designed for roughing and finishing.

At the time, Baldor’s standard approach to roughing out the holes was orbital milling with a 3/4-inch, four-flute solid carbide end mill.  In orbital milling, the technique is to plunge about 0.100 inch and then orbit the tool at a very careful feedrate (so it will not snap off, as brittle solid carbide end mills are likely to do.)  Then, the process is repeated until there is a break through, with the hope that the resulting slug doesn’t pose a safety hazard or damage the tool.  It’s basically start-and-stop.  For each hole that Baldor machinists produced in the two-inch thick walls, they had to follow about 20 steps.

The corkscrew milling technique has been established for some time, but until recently its practical applications were limited.  In corkscrew milling, the toolpath is helical and continuous, not stepped, as in orbital milling.  The principal applications included already-opened holes and thin materials, and horizontal setups where gravity took care of chip clearance.

“All-directional turning is not necessarily new, but the tools that we would customarily use for all-directional turning were round inserts or neutral-handed inserts, and you can’t create square corners with those shapes. The newer inserts may look similar to ISO inserts in some regard, but geometries and technologies are put in place for chip breaking,” explained Keith Brake, regional product manager, turning - Americas for Sandvik Coromant. “For the multidirectional process to work, with chip control in mind, they are now their own specific shape, at least for Sandvik Coromant.”

The change paid off immediately, however.  The cycle time to rough out each hole in the cover dropped from 17 minutes to five minutes, exactly as in the test, and edge life improved by 10 to 1.  The previous solid -carbide roughing cutter lasted through just one hole, while a set of edges on the indexable cutter lasts through ten.  “The new method is not only much faster, it also involves much less maintenance,” according to Glasper.

Glasper chose the explosion proof cover as a starting point in the search for productivity improvements because, as one of higher-volume items requiring large holes, Baldor would readily recognize the savings because of it cost.  “Solve it on the highest-volume part, and we get the biggest immediate payback,” he explained.

Think of Sandvik Coromant’s multidirectional turning as the complete package; a system developed to consolidate insert inventory, enhance productivity, and improve tool life while using unique software.

“With multidirectional tools, the common function is to perform both back turning (roughing) and front turning (finishing),” said Gill.

So that is one difference from a regular insert. The other difference is the ability of these tools to perform high-feed pull turning. The insert is inclined, and, at the same DOC, the chip is wider and thinner, which allows for a faster feed to be used.

“Our second generation of CoroTurn Prime is a true eight-edged system. So, if it's properly programmed and properly implemented, you can use the chip thinning side or the high-efficiency side for your roughing application, and then you can turn right around with the same tool and you can use the other side for finishing operations without ever making a tool change,” said Brake.

Baldor manufactures electric motors and adjustable speed drives, and the Gainesville operation has 400 employees producing AC and DC motors (1-1,500 HP).

Making large holes in ferrous metals can bepretty slow going.  Big twist drills take a lot of power, and can be expensive and hard-to-find in odd sizes.  Flame cutting will work only if the material is flat plate, plus it is a cumbersome process and leaves a lot of finishing work to be done.  Trepanning, involving expensive, dedicated tools, is limited to repetitive, high-volume work.  Orbital milling is faster and more versatile, but there is always the risk of snapping off the brittle solid-carbide end mills.

Soon after the successful trial, Glasper and commodity manager Doug Bushey shared their experience via one of the weekly idea-sharing conference calls that Baldor conducts with all of its plants.   As a result, ten other Baldor plants now are in various implementation stages with the corkscrew milling method.

Both inserts create thin, wide chips, which spread the load away from the nose radius. This results in increased tool life or allows for increasing the cutting data.

Each multidirectional tool can perform roughing and finishing. Because there are two separate cutting edges, tool life of the entire tool is high.

According to Brake, roughing cycle times can be reduced by as much as 30 per cent with proper implementation of the CoroTurn Prime tooling and methodology. This is achieved with the higher productivity that the high feed side is capable of.

Multidirectional tool can perform roughing and finishing. Because there are two separate cutting edges, tool life of the entire tool is high. Tungaloy Canada

This rail design, called Y-PRISM, has a rail on the shim/toolholder and matching slot on the insert for tight interlocking and secure clamping. It helps prevent cutting forces from affecting the tool position in any direction and ensures high stability.

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The production gains achieved at Baldor Gainesville stem from a total method change based on completely different tool designs, according to Ingersoll’s milling product manager Mike Dieken.  “First, the cut is continuous down the helical toolpath, not start-and-stop,” he began.

In Chris Pope’s first trial run at Baldor, a three-flute Hi-Feed Dekamill running in the corkscrew mode completed each hole in five minutes, as opposed to a 17-minute cycle recorded for a comparable job with the orbiting method.  For the trial, the cutter advanced helically 0.031-inch per “orbit,” opening the hole in six revolutions, and it orbited at 214 IPM versus 12 IPM for orbital milling.  Surface speed was 800 SFPM, versus 335 SFPM.

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Multidirectional tools are an obvious fit for complex turning applications that require multiple kinds of turning operations to be performed. However, that’s not all they are good for.

“Because you can use the same insert to rough and finish, you can free up a slot in the turret for another turning tool,” Brake.

Recently, Baldor Electric Co.’s Gainesville, Ga. plant improved the large hole-making process for one part so successfully that it adapted the approach for 10 other jobs at there — and its now being considering for jobs at several other Baldor Electric plants.

For ideas he asked Ingersoll’s Chris Pope, who suggested the corkscrew technique using a larger-diameter indexable mill with high feed inserts.  “In corkscrew milling, the cutter advances continuously as it orbits,” Pope explained.  “And, the high-feed insert geometry means you can advance faster with shallower cuts, getting through the material faster while reducing cutting forces and spindle loads.”

“Multidirectional tools can be implemented easily,” said Hartej Gill, product manager for Tungaloy Canada. “We give manufacturers a piece of code with the special program required.”

An award-winning writer and graduate of the Sheridan College journalism program, he has published articles worldwide in a variety of industries, including manufacturing, pharmaceutical, medical, infrastructure, and entertainment.