CNC machine maker Makino has developed a high-speed Z-axis structure for its EDNC-Series sinker EDM machines, destined for use in large workpiece applications requiring high accuracy and fine surface finishes.
Makino says the new HS-Rib high-speed Z-axis technology delivers improved speed, lower electrode wear and more uniform finishes in large sinker EDM processes.
“When it comes to reducing sinker EDM cycle times, it is not the maximum jump speed that is important, but rather the acceleration speed,” Makino says, adding that its Z-axis technology has a jump rate four times faster and Z-axis acceleration rate 30 times faster than previous technologies.
This capability produces a more efficient hydraulic effect during machine processing, which helps evacuate debris from the spark gap, even in deep-rib features.
“As with all machining processes, there’s an insatiable desire to reduce cycle times while meeting part-quality requirements in sinker EDM processing,” Makino EDM product manager Brian Pfluger says. “Fulfilling these needs involves a number of considerations, including how to process for best speed and efficiency, minimise electrode manufacturing requirements and reduce electrode wear to achieve the best possible surface finish quality.
“Our new high-speed Z-axis technology, combined with Makino’s SuperSpark IV, helps support these factors, providing an ideal balance for efficiency in both electrode consumption and cycle times without the need for external auxiliary flushing.”
The Z-axis design offers highly flexible processing capabilities, Pfluger says, including a jump rate of 20 m per minute with 1.5-G acceleration, Z-axis strokes ranging from 500mm to 800mm, and programming of orbital machining patterns with no amperage limitations. The use of direct-drive motor technology and liquid cooling within the Z-axis structure ensures sustained thermal stability and precise depth control, and supports electrode weights of up to 100kg.
Makino offers four process strategies for optimal performance based on user requirements for speed, surface quality, accuracy and electrode wear:
- Low Wear Settings: Provide a single-electrode rough and finish process.
- Advanced Orbit and Jump Settings: Improve machining speeds and surface finish consistency.
- High-Speed Z-Axis: Improve machining speeds and accuracy.
- Aggressive Power Settings: Optimise machining speed (sacrifices electrode wear).
The company says its EDNC-Series sinker EDM machines “combine rigid and precise construction, simple programming and advanced performance features for accurate EDMing of large workpieces”.
Equipped with the new high-speed Z-axis technology, it adds, these large, heavy-duty machines can produce deep ribs as fast as, or faster than, the smallest sinker EDM machines on the market.
“Automatic tool change and adaptive controls enable high levels of unattended machining without the need for operator intervention, and is further supported with advanced automatic jump machining controls to optimize debris removal without the need for external flushing.”