You may be an experienced machinist or an expert programmer – but do you really know how a CNC machine works? What it is designed to do is often quite different from how it turns or grinds or drills, or does whatever machining process it performs.
An electrical or mechanical engineer will know that a CNC machine works because within its cabinet there are a series of a high-powered, high-precision electric motors. Asking how that electric motor works begins a tale that may become more compelling if the developers at ECM PCB Stator Technology continue to reframe the discussion. ECM is a U.S.-based startup that uses patented PCB Stator technology to design custom motors for multiple electric applications.
A “stator” is a stationary component of a rotary motor; when the stator is energized via a DC supply – and through the motor’s controller – it spins the motor shaft to add a specific speed and torque that powers the machine.
Note, the typical stator is made of multiple coils of wire, in a structure that is scaled to the power output of the engine it serves. It generates heat and endures stress as the motor runs. It’s a critical subsystem in the machining process.
The ECM PCB Stator Technology innovation is to replace the copper windings found in conventional electric motors with a much lighter, printed circuit board – the method widely used by engineers to link individual components of electrical systems.
ECM’s development makes the PCB stator the central component for harnessing electric energy efficiently, to create a highly predictable magnetic field that generates the precise torque and horsepower required at the motor shaft, within a fully integrated rotor magnet assembly optimized for specified end use applications.
Also, ECM’s PrintStator software platform – a recent beta release – makes it possible to quickly design, model, and prototype optimized PCB stator electric motors that are lighter, faster, quieter, and more energy-efficient and space-conserving than the bulky and “design-constrained” electric motors still widely used.
Deep connections
Both developments are traced to research by ECM’s Chief Technology Officer, well-known electrical engineer Dr. Steven Shaw, who received his Ph.D. from MIT.
In 2022, the start-up business has designed over 70 “uniquely optimized electric motors,” working with 34 partners and a SaaS offering for designing new installations.
“The breadth of ECM’s partners and range of use cases actually gets to the crux of our mission and most recent big move: the beta release of PrintStator in fourth-quarter 2022,” said Rob Luchars, vice president, Business Development. He explained that the firm’s patented PCB Stators have been adopted for “bespoke, axial flux electric motors” powering applications in a range of industries, including HVAC, consumer electronics, e-mobility, medical devices, robotics, aerospace, defense, and many others. The potential for powering computer-numerical control (CNC) processes – more power in a smaller package that is more precisely customizable – is surely promising.
“There are millions of applications that require electric motors in these verticals and PCB Stator electric motor design technology offers benefits to all those applications, in performance, efficiency, and sustainability over other electric motor alternatives,” Luchars reported.
Consumption and maintenance
Energy costs and liabilities are looming concerns for manufacturers, so they will be encouraged to note that the PCB Stator technology and PrintStator software can create electric motor designs that require significantly less raw materials in production, making the per-unit cost very competitive. Luchars added that ECM-designed motors can achieve energy efficiencies in the mid-90s range – “a huge jump compared to other motor technologies.”
One of the greatest consumption and cost improvements with PCB Stator technology (versus standard stator design) is the ability to design a perfect fit motor for the application — in both specs and dimensions — which drastically increases the system efficiency of electric systems.
There are maintenance considerations, too. PCB Stator motors are much more reliable than alternative motor technologies because the copper is encapsulated in standard PCB material (FR4), which prevents insulation failures, the leading cause of motor malfunction.
The cost to install an ECM PCB Stator motor varies according to the application, and what system it is meant to replace. Luchars explained that a critical advantage of the new option is that it’s software-based, “so we can quickly project the cost of a motor for any application and quantify the competitive advantages precisely.
“ECM can also take exact specifications from our partners for any application and model that is in PrintStator before going to prototype,” he added. “That way we can more quickly and accurately assess product fit (case by case), and achieve more accuracy and fewer failures when a design goes forward to production.”
How about the earlier proposition… Powering CNC machines? Luchars indicated that to-date there are just a few such examples, and the company views CNC systems as “ripe” for PCB stator motors. He revealed that ECM is “in dialogue in several directions to lead there."
“PCB stator motors have been used in a wide variety of high-precision and high-torque applications that lend themselves very well to the CNC industry. PCB Stator technology can power CNC-design machines and then, of course, be integrated into electric motors systems for outputs of CNC design,” he detailed.
Power potential
As of now, ECM’s primary focus is design for electric motors rated at 20 kW or under, though Luchars revealed that the company is increasing its scope beyond that range, and expects to expand in that direction shortly.
The potential for designing CNC machines powered by motors developed with PCB Stator technology is “tremendous,” he explained. Luchars highlighted three primary reasons.
“First, due to their axial flux configuration, utilization of PCB stators with rotary axis tables — either vertical or horizontal — provide benefits of overall ‘height/stick out,’ reduction along with lower overall weight.
“Additionally, PCB Stators lend themselves to hollow shaft configurations that are ideal for a variety of CNC applications,” he said. “Aside from the conventional 40-taper machines, PCB Stator motors can also be beneficial in micro-machining applications – where positional accuracy is paramount – due to the zero-cogging torque of PCB Stator motors and where managing thermal expansion is key.
“Finally, by using ECM’s PrintStator software there is the ability to create motors that can fit in very thin axial spaces and conform to the non-standard enclosures,” Luchars detailed.