M.2 Stepper Modules?! The Innovative New NYMS.2 Standard Banks on the Idea

Stepper motors are wonderful and serve as the basis for motion systems across many different applications, such as 3D printing and CNC milling. But unlike regular old DC motors, power alone won’t make stepper motors spin. Stepper motors require special drivers to modulate power between the coils in sequence. Those drivers are key components of motion control systems and the innovative new open source NYSM.2 standard from Boltz R&D gives them a more robust connection with an M.2 interface.

If you recognize the “M.2” name, it is probably because you installed an SSD or PCI-E card on your computer’s motherboard. M.2 is a relatively new specification for high-throughput edge connectors and boards.

So why would Boltz R&D want to use an M.2 interface for stepper driver modules? Right now, there isn’t any real standard for those module connections. On the hobbyist side, a lot of motion control boards with user-replaceable stepper drivers use simple pin headers. But that is far from being ubiquitous and pin headers really aren’t ideal for the job. The pins bend easily, the modules can be accidentally put in backwards, they’re bulky, and they can only carry limited current. The only real advantage of pin headers is that they’re cheap.

M.2 — specifically Key B in this case — solves all of those problems. It is low-profile and has the key to prevent improper insertion. There are plenty of pins for data transmission and enough leftover pins for power. The NYSM.2 standard sets aside eight pins just for power. Each can carry 0.5 amps at 25V, for a total of 100W (4A at 25V) to the stepper driver. That’s enough for the stepper motors on almost every 3D printer made, as well as many smaller CNC mills and other machines.

NYSM.2 is a standard and not a specific driver module. It should work with just about any stepper driver on the market that supports SPI or UART communication, which is basically all of them. For example, Boltz R&D designed a stepper driver module with the NYSM.2 standard for TMC2209 drivers, which are very popular.

Boltz R&D plans to integrated the NYSM.2 standard connectors into their SmartPrintCoreH7x 3D printer control board that we covered previously. But, again, this is an open source standard and you can start using it right now in your own custom designs.

It is always an incredibly difficult task to get an industry to adopt a new standard and we can’t predict if that will happen with NYSM.2, but it does seem to have potential and we’re curious to see where it goes.