Eroding and polishing PCD- and PCBN-tipped cutting tools in one clamping helps ensure toolmakers accurately and efficiently produce those tools, and Vollmer of America Corp. has introduced a universal machine to do that. The QXD 200 is a 6-axis machine for manufacturing such cutters up to 250mm in diameter and 200mm in length.
To boost productivity, the machine has a generator that reduces EDM erosion times by up to 30 percent compared to the company’s previous generator, according to Scott Ries, product manager for the PCD group at Vollmer. The rotary, or disc, erosion process typically leaves 10µm to 20µm of superhard material for polishing with a grinding wheel, he noted.
Ries added that the erosion process is able to impart a cutting edge finish as fine as 0.18µm Ra, and a polished edge can be as fine as 0.05µm Ra.
Courtesy of Vollmer
Through the integrated polishing capability, a toolmaker can produce a PCD- or PCBN-tipped tool in one clamping on the QXD 200 from Vollmer.
The machine can also measure the grinding wheels, electrodes and workpiece location within the machining environment. “The machine understands where everything is located and what the dimensions are,” Ries said, adding that the machine’s automatic toolchanger holds a combination of up to six wheels and electrodes. “It provides the versatility to run different geometries without having an operator change electrodes, change wheels or remeasure where they’re at because [the wheels and electrodes] were taken off and put back on.”
Because of the novel arrangement of the axes, a tool is machined in a suspended position, the company reports. Ries explained that Vollmer developed the vertical axis to improve tool runout because a tool can deflect due to its own weight when held with the conventional horizontal axis. That also helps keep the workpiece interface cleaner because debris is flushed down the tool. “It makes measurements more accurate as well,” he said.
To eliminate the need to tweak a 3-D model of a tool prior to producing it, Vollmer developed ExLevel software to create “an exact replica of that 3-D model” in which the manufactured tool’s tolerances don’t vary from the model, Ries noted. The virtual simulation program also enables end users to verify that a tool design is correct and, if not, modify it before production begins by importing the tool’s 3-D model into their modeling software, he explained.
The QXD 200 offers three options for delivering tools to the machine: a traditional magazine, a pallet system for 39 large-diameter workpieces and a pallet system for 64 small-diameter workpieces. The pallet systems are positioned on tracks outside the machine and enable integration of other parts of the manufacturing process, such as brazing and inspection, into the tool delivery system, Ries noted.
For more information about the QXD 200 and Vollmer of America Corp., Carnegie, Pa., call (412) 278-0655 or visit www.vollmer-us.com.
Related Glossary Terms
- 3-D
3-D
Way of displaying real-world objects in a natural way by showing depth, height and width. This system uses the X, Y and Z axes.
- automatic toolchanger
automatic toolchanger
Mechanism typically included in a machining center that, on the appropriate command, removes one cutting tool from the spindle nose and replaces it with another. The changer restores the used tool to the magazine and selects and withdraws the next desired tool from the storage magazine. The changer is controlled by a set of prerecorded/predetermined instructions associated with the part(s) to be produced.
- electrical-discharge machining ( EDM)
electrical-discharge machining ( EDM)
Process that vaporizes conductive materials by controlled application of pulsed electrical current that flows between a workpiece and electrode (tool) in a dielectric fluid. Permits machining shapes to tight accuracies without the internal stresses conventional machining often generates. Useful in diemaking.
- 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.
- grinding wheel
grinding wheel
Wheel formed from abrasive material mixed in a suitable matrix. Takes a variety of shapes but falls into two basic categories: one that cuts on its periphery, as in reciprocating grinding, and one that cuts on its side or face, as in tool and cutter grinding.
- polishing
polishing
Abrasive process that improves surface finish and blends contours. Abrasive particles attached to a flexible backing abrade the workpiece.
- polycrystalline diamond ( PCD)
polycrystalline diamond ( PCD)
Cutting tool material consisting of natural or synthetic diamond crystals bonded together under high pressure at elevated temperatures. PCD is available as a tip brazed to a carbide insert carrier. Used for machining nonferrous alloys and nonmetallic materials at high cutting speeds.
- toolchanger
toolchanger
Carriage or drum attached to a machining center that holds tools until needed; when a tool is needed, the toolchanger inserts the tool into the machine spindle. See automatic toolchanger.
Author
Alan holds a bachelor’s degree in journalism from Southern Illinois University Carbondale. Including his 20 years at CTE, Alan has more than 30 years of trade journalism experience.
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