This slideshow provides a brief overview of technology on display at Makino's recent Technology Expo and Micromachining Conference.
The company unveiled four new wire EDM machines: the U3 (shown here) and the larger U6, as well as the U3 and U6 “HEAT” (High Energy Applied Technology), a variation on the standard models designed for greater horsepower, speed and flushing capability. The machines are the first equipped with the company’s Hypercut Technology, which produces surface finishes as fine as 3 µm Rz (15 µin Ra) on standard tool steels in three passes. The Pro-Tech anti-electrolysis circuit protects the entire workpiece (as opposed to just the cutting zone) against rust without chemical additives. Other notable features include a stacked-axes configuration that ensures support throughout the entire range of travel, large, dual-anchored ballscrews, linear guideways, and both rotary encoder and glass scale feedback. To save space, the dielectric reservoir is built into the machine casting.
Along with the U3 and U6 EDMs, the company introduced a new CNC: the Hyper-i. It touts the control as particularly intuitive and easy to use, and not just because of its 24-inch HD touchscreen interface. For example, a feature called the “E-Tech Doctor” provides intelligent help functionality, such as the ability to automatically change and update power settings according to cutting conditions. Machine manuals, diagnostic tools, machine utilization data and more are also embedded within the control.
Attendees begin to gather around a demonstration of cutting a die-cast insert on a Makino five-axis D300. The takeaway here was that five-axis capability can speed roughing operations by machining at angles that maximize the capability of multi-flute tools.
A closer look at the part and tools from the D300 demo in the previous picture. During roughing, a three-axis machine might be limited to using only a portion of the tip of each tool at a light axial cutting depth. In contrast, the D300 can employ 4+1 strategies to position the tool to closely follow the part’s contour with its entire axial flute length at a very light radial engagement level. This strategy reduces the need for semi-finishing and improves productivity by ensuring full use of all the tool’s cutting edges.
A key takeaway from one presentation at the Micromachining Conference was the idea that small, table-top style machines might not be the best solution for small, precise work. On the contrary, a robust construction like that of Makino’s iQ300—which is “built like a machining center,” as VMC manager Bill Howard put it—ensures the stiffness and rigidity necessary to achieve submicron accuracy. Locating the X and Z axes under the column and the Y axis under the table ensures support throughout the range of travel, while linear motors and precision rolling guideways provide smooth feed motion. For temperature control, the machine features bed and column insulation, the company’s patented core-cool spindle technology, and cooling oil circulated throughout the structure.
To showcase the capabilities of the iQ300, the company had the VMC milling this free form optic from 6061 T6 Aluminum to a surface roughness of 12.903mm Ra. Cycle time was 20 hours and 52 minutes.
A few of the micromachining demonstrations involved milling directly into carbide. This can offer an alternative to time-consuming grinding or EDM operations. Here, a V33i machines a punch from 92-HRA micro-grain carbide using a Union Tool UDCB ballnose end mill. According to company representatives, this is possible primarily thanks to the rigidity of the machine and the tool’s CVD-applied, ultra-hard diamond coating.
A closer look at the carbide punch machined on the Makino V33i.
This 88-HRA cemented carbide part was cut on the iQ300 using three different tools. Roughing took 2 hours and 13 minutes with electroplated diamond end mill. The 2 hour, 23 minute semi-finishing operation employed a tool using a CVD-applied diamond coating. The PCD tool used in the final operation is less wear resistant and ill-suited for roughing, but offered the necessary precision to achieve the mirror-like surface finish visible in the final-stage part at bottom. The finishing operation took 64 hours.
Designed for precision machining of small parts, the UPN-01 wire EDM is capable of achieving surface finishes ranging to 0.17µm Rz and accuracy of ±0.5 µm. The machine features a horizontal configuration in which the workpiece is suspended vertically. According to the company, this design ensures material removed during machining falls harmlessly away from the cutting zone. Along with options for workpiece indexing and an automatic workpiece changing system, it also facilitates reliable unattended operation. Also notable is the automatic wire threader, which reliably threads wire as small as 0.02 mm in diameter. The system works via two nozzles on either side of the workpiece, one of which discharges a jet of air to push the wire through while the other creates suction to pull it into place.
Metrology is particularly critical for small-part applications, and Makino invited a number of partners in this area to showcase their technology at the Micromachining Conference. Werth’s fixed-bridge VideoCheck multi-sensor CMM features a granite construction and air-bearing technology for rigidity and precision. Available sensors include optical, lasers, and touch-trigger, fiber and scanning probes.
Another metrology system provider, Alicona, highlighted what it calls “closed-loop machining” in this demonstration on a Makino EDAF sinker EDM integrated with one of its white-light scanning unit. The unit periodically measures depth, surface and form during the machining process, and the machine adjusts automatically according to the results. This proactive, on-machine measurement saves time and eliminates a potential source of error by limiting setups.
Back-to-back events drew hundreds to Makino’s Auburn Hills, Michigan tech center last week for technical presentations, machine demos, networking and more. Here is a brief overview of what I saw at the Micromachining Conference on September 10 and the Technology Expo on September 11 and 12th.