EDM Achieving the next level of micromachining
With Makino’s EDAC1 Ram EDM machine, the US-based company EDM Department was able to achieve tighter micro-tolerance and improved process capabilities for all its applications across the aerospace and medical industries. The addition of the optical 3-D metrology system from Infinite Focus to the EDM machine enabled the company to achieve an accuracy of 1.7 microns!
Manufacturers like Makino are offering ultra-precision micromachining technologies, like the EDAC1 Ram EDM machine, to address the need for increasingly miniaturised part production and mold development. And one company, EDM Department of Bartlett, Illinois in the USA has even found a way to expand their micromachining capabilities in this unique industry. Uniting their highly stable Ram EDM machine with new metrology, they now have an even more successful and unprecedented inspection, measurement, and micro-tolerance machining solution with which both their team and customers have been impressed.
EDM Department serves multiple industries: the aerospace industry with high-performance connectors, defence communications, and developmental work; the medical industry with surgical tools, surgical implant, and medical developmental work; as well as other industries including telecommunications.
As the face of North American manufacturing continues to change, the need for more complex, micro and nano projects is on the rise, and the company has seen an increase in new and challenging requests and design reviews.
“We consistently find ourselves confronted with the need to do things smaller than we have ever accomplished before,” says Mark Raleigh, CEO of EDM Department. “When we began to consider the addition of micromachining capabilities, we were producing features and elements at the 100-micron level. Today, 25-micron features are quite common, with recent challenges to control 10-micron features and elements. We needed a robust and stable micro-tolerance machining solution that would get us closer to the 1-micron scale.”
The firm turned to Makino for this solution. Looking for micromachining technology that would define the future of the company, the firm purchased Makino’s EDAC1 Ram EDM machine. And, after running it through initial positioning, surface finish, and general machining tests, the company realised relatively quickly that it was exactly what they had been seeking. “In the beginning, we ran this machine through the full gauntlet, resulting in precision accuracy with extraordinary repeatability,” says Raleigh. “We discovered that the EDM machine is actually two to three times as capable, compared to what was expected.”
The average daily true positional drift with the EDM machine is less than 2 microns and less than 3 microns over 27 days for the XY plane.
Ultra-high-accuracy Ram EDM
Makino’s EDAC1 is an ultra-high-accuracy Ram EDM ideal for micro-tolerance mold applications. Designed and built for industries requiring the highest precision achievable, this ultra-precision machining center is capable of producing corner radii of 0.00019 inches (0.005mm) and surface-finish quality of 0.000024 inches (0.6 micron) Ry, while providing repeatability in the submicron range. It also achieves positional and pitch accuracies of ± 0.00004 inches (1.0 micron).
With thermal barriers and a Z-axis stabilizer, the EDM machine can cool the Z-axis and decrease thermal growth for increased accuracy. The machine’s C-axis and Mi head also allow for precise electrode positioning accuracy at multiple angles.
The most remarkable impact that the firm has seen with the EDM machine lies in its increased accuracy and stability. They are using this machine within all of their applications and are experiencing tighter micro-tolerance and improved process capabilities as compared to previous machines.
“To quantify accuracy and stability, we have to include the effect that the environment creates, so we continuously reference our machine position over time,” says Raleigh. “The average daily true positional drift with the EDM machine is less than 2 microns and less than 3 microns over 27 days for the XY plane. The Z-axis is less than 1 micron daily and is considerably less than 2 microns on a 27-day period.”
The company has also benefited from significant cost savings with the EDM machine due to the impressive repeatability, it provides. With this repeatability, the firm has achieved enhanced precision, production, and reproducibility, giving it a competitive edge. Since the purchase, the company’s return on investment (ROI) is exceeding all expectations on the development side by approximately 50 percent.
“We’re getting what we expected. It has taken us to the next level of micromachining and is fully capable of what we are trying to achieve,” says Raleigh.
The combination of the EDM machine and Infinite Focus enables even better surface-finish capabilities than initially thought—a 7 percent improvement—and we still have not utilised the machine’s full potential.
Better surface-finish capabilities
With Infinite Focus’ optical 3-D metrology system, a unique measurement system that generates high-resolution, repeatable, and traceable results, the company was able to implement the EDM machine in unique ways that deliver impressive results. By pairing the stability and tight tolerances of the EDM machine with the optical 3-D metrology system, the firm has achieved an overall machine performance that continues to surpass expectations. It is now capable of producing surface finishes that are not found elsewhere, allowing for unbeatable repeatability, reproducibility, and precision.
“With a better understanding of the surface being produced, we are now able to reduce the safety margin normally used, giving us better utilisation and efficiency of our electrodes,” says Raleigh. “The combination of the EDM machine and Infinite Focus enables even better surface-finish capabilities than initially thought—a 7 percent improvement—and we still have not utilised the machine’s full potential.”
When EDM Department first purchased the machine, they were able to achieve ±4 microns. By implementing a tooling, equipment, and analysis solution with Infinite Focus, it achieved 1.7 microns. And, as it moves forward, it plans to continue pushing the envelope, breaking additional barriers in accuracy and precision.
“In the past, several projects from existing customers had to be shelved, as elements below 50 microns were just not feasible,” says Raleigh. “Now, with these two technologies, we can make, measure, and see elements well below 20 microns with stable and accountable processes, allowing us to enhance our micro-tolerance production capabilities and opening the door for several new opportunities.”
Exciting time for micro-manufacturing
For EDM Department, the possibilities for success in this finite industry are endless. As they look ahead, they are hoping to push for even tighter tolerances and accuracies. “This is an exciting time for micro-manufacturing,” says Raleigh. “Because of these two new technologies, we will one day be able to say ‘Now accepting 1-micron tolerances.’