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END USERS: Precor, (800) 786-8404, www.precor.com: Hardy Engineering & Manufacturing, (253) 735-6488, www.hardyem.com. CHALLENGE: Boost machining productivity. SOLUTION: A high-performance milling tool. SOLUTION PROVIDER: SwiftCARBCNC, (800) 227-9876, www.swiftcarb.com
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When it comes to speed, the RampMill is a top performer, according to Aaron Fike, sales and marketing manager of toolmaker SwiftCARBCNC, Kent, Wash. In pocketing applications when cutting difficult-to-machine materials like titanium, Inconel and tool steel, Fike said his tool cuts faster than the competition’s. “We’ve done extensive testing with the RampMill. Apples to apples, we pocket five to 10 times faster than anyone in difficult materials.”
Even in less demanding materials, the RampMill performs well. Merrill Kincade, senior programmer at fitness equipment manufacturer Precor, Woodinville, Wash., explained how his company was able to increase production rates nearly 50 percent when machining an aluminum extrusion. “Previously, we were roughing and semifinishing a 1.574 "-dia. × 1.315 "-deep through-hole using three tools: a 1¼ " indexable-insert drill; a 1 ", 4-flute endmill; and an indexable twin cutter. One ¾ " RampMill replaced all that, and our output went from just over eight cycles per shift to 12.”
RampMill is an endmill that isn’t an endmill, according to Fike. “Take a typical milling job in Ti6Al-4V, for example,” he said. “Using a conventional endmill, ramping at an angle of more than 0.75° in titanium is not practical, whereas we ramp routinely at 7° in titanium, nearly 10 times the maximum angle of an endmill, and at higher feeds and speeds. The RampMill can helically interpolate 20 to 30 times faster than an endmill.”
RampMill has more than 1,000 patent-pending design claims, including unique geometric features, through-coolant and a proprietary coating, according to Fike. “The only thing that the RampMill and an endmill have in common is that both can do side milling,” he said.
According to Fike, the RampMill was designed for controlled radial-engagement toolpaths. “Toolpath is extremely important in high-cube machining,” he said. “When you’re pushing a tool as hard as we can with the RampMill, you have to maintain a constant load on the cutter and consistent cutter engagement throughout the toolpath, especially in the corners—you can’t slow down or you’re dead. Up until the past year or so, most CAD/CAM manufacturers didn’t have a controlled radial-engagement toolpath. But today, probably 75 to 80 percent of the CAM makers have developed new cutter paths that work great.”
Courtesy of SwiftCARBCNC
A RampMill consistently produces short chips while circular interpolating a 4140 steel workpiece at 2 diameters deep and a 260-ipm feed rate.
Anyone who’s ever listened to an endmill chomping and grinding on recut chips knows high-pressure through-coolant is a huge advantage. “You can’t recut chips in titanium and Inconel,” Fike said. “If you try, any tool will fail almost immediately. Our center coolant hole solves this problem. Toolmakers have always steered away from this in endmills because it kills the tool’s center-cutting ability, but by designing a tool that ramps rather than plunges, we’ve eliminated that limitation. As a result, tool life when pocketing goes up two to seven times.”
SwiftCarb purchased a coating chamber to apply its MDC coating to the RampMill. “We started out trying to devise a coating just for cutting titanium, but ended up with a coating that works in most workpiece materials,” Fike said. “MDC has great lubricity, excellent wear resistance and high heat resistance. The result is you can replace three different application-specific coatings with just one high-performance production coating.”
Of course, success with the RampMill isn’t foolproof. Because of the demanding toolpaths involved with constant radial engagement, it requires a responsive and rigid machine tool. “You can’t slow down or dwell in the corners. If you do, the material workhardens and no tool can survive that,” Fike said.
Courtesy of SwiftCARBCNC
It also requires the right toolholder. “Forget about commodity endmill holders,” he said. “Try running 450 sfm in titanium with a sidelock holder and you’re not going to make it half an inch. You need a good milling chuck or a shrink-fit holder.”
One shop seeing impressive results with the RampMill in titanium is Hardy Engineering & Manufacturing, Auburn, Wash. According to Manufacturing Engineer Jeff Olberg, Hardy was able to cut cycle time in half by switching from conventional endmills to the RampMill. He said: “We machine a lift truck component from a titanium block measuring 6 "×7½ "×9 ". Our old process took 10 hours and required a number of tool changes. Now we mill the whole thing out in just 5 hours with one standard-length ½ " RampMill, and have increased tool life sixfold. It’s a great value.”
Parts manufacturing comes down to how fast a shop can get things done. “That’s what they get paid for,” Fike said. “And that’s why we developed the RampMill—to make parts faster. There’s nowhere that it doesn’t work, whether you have a 100-hp or 10-hp machine. It’s all about getting the most out of what you already have.”
Related Glossary Terms
- chuck
chuck
Workholding device that affixes to a mill, lathe or drill-press spindle. It holds a tool or workpiece by one end, allowing it to be rotated. May also be fitted to the machine table to hold a workpiece. Two or more adjustable jaws actually hold the tool or part. May be actuated manually, pneumatically, hydraulically or electrically. See collet.
- computer-aided manufacturing ( CAM)
computer-aided manufacturing ( CAM)
Use of computers to control machining and manufacturing processes.
- coolant
coolant
Fluid that reduces temperature buildup at the tool/workpiece interface during machining. Normally takes the form of a liquid such as soluble or chemical mixtures (semisynthetic, synthetic) but can be pressurized air or other gas. Because of water’s ability to absorb great quantities of heat, it is widely used as a coolant and vehicle for various cutting compounds, with the water-to-compound ratio varying with the machining task. See cutting fluid; semisynthetic cutting fluid; soluble-oil cutting fluid; synthetic cutting fluid.
- endmill
endmill
Milling cutter held by its shank that cuts on its periphery and, if so configured, on its free end. Takes a variety of shapes (single- and double-end, roughing, ballnose and cup-end) and sizes (stub, medium, long and extra-long). Also comes with differing numbers of flutes.
- extrusion
extrusion
Conversion of an ingot or billet into lengths of uniform cross section by forcing metal to flow plastically through a die orifice.
- feed
feed
Rate of change of position of the tool as a whole, relative to the workpiece while cutting.
- gang cutting ( milling)
gang cutting ( milling)
Machining with several cutters mounted on a single arbor, generally for simultaneous cutting.
- grinding
grinding
Machining operation in which material is removed from the workpiece by a powered abrasive wheel, stone, belt, paste, sheet, compound, slurry, etc. Takes various forms: surface grinding (creates flat and/or squared surfaces); cylindrical grinding (for external cylindrical and tapered shapes, fillets, undercuts, etc.); centerless grinding; chamfering; thread and form grinding; tool and cutter grinding; offhand grinding; lapping and polishing (grinding with extremely fine grits to create ultrasmooth surfaces); honing; and disc grinding.
- lubricity
lubricity
Measure of the relative efficiency with which a cutting fluid or lubricant reduces friction between surfaces.
- milling
milling
Machining operation in which metal or other material is removed by applying power to a rotating cutter. In vertical milling, the cutting tool is mounted vertically on the spindle. In horizontal milling, the cutting tool is mounted horizontally, either directly on the spindle or on an arbor. Horizontal milling is further broken down into conventional milling, where the cutter rotates opposite the direction of feed, or “up” into the workpiece; and climb milling, where the cutter rotates in the direction of feed, or “down” into the workpiece. Milling operations include plane or surface milling, endmilling, facemilling, angle milling, form milling and profiling.
- milling machine ( mill)
milling machine ( mill)
Runs endmills and arbor-mounted milling cutters. Features include a head with a spindle that drives the cutters; a column, knee and table that provide motion in the three Cartesian axes; and a base that supports the components and houses the cutting-fluid pump and reservoir. The work is mounted on the table and fed into the rotating cutter or endmill to accomplish the milling steps; vertical milling machines also feed endmills into the work by means of a spindle-mounted quill. Models range from small manual machines to big bed-type and duplex mills. All take one of three basic forms: vertical, horizontal or convertible horizontal/vertical. Vertical machines may be knee-type (the table is mounted on a knee that can be elevated) or bed-type (the table is securely supported and only moves horizontally). In general, horizontal machines are bigger and more powerful, while vertical machines are lighter but more versatile and easier to set up and operate.
- through-hole
through-hole
Hole or cavity cut in a solid shape that connects with other holes or extends all the way through the workpiece.
- toolholder
toolholder
Secures a cutting tool during a machining operation. Basic types include block, cartridge, chuck, collet, fixed, modular, quick-change and rotating.
- toolpath( cutter path)
toolpath( cutter path)
2-D or 3-D path generated by program code or a CAM system and followed by tool when machining a part.
- wear resistance
wear resistance
Ability of the tool to withstand stresses that cause it to wear during cutting; an attribute linked to alloy composition, base material, thermal conditions, type of tooling and operation and other variables.
