STEPPERONLINE CNC Stepper Motor Driver 1.0-4.2A 20-50VDC 1/128 Micro-Step Resolutions for Nema 17 and 23 Stepper Motor

I'm very happy with these drivers. I bought three of them to drive the two NEMA-23 steppers for the Y-axis and for one NEMA-23 stepper on the X-axis. I switched from using the built-in drivers on my Smoothieboard clone, which I suspected were not driving the motors adequately. Once I switched over, this motor driver was much quieter and I am now getting consistent results.However, there are a few lessons learned along the way. First of all, there are some rather odd wiring suggestions floating around for connecting these to the smoothieboard. The simplest, most obvious solution is to take the 4-wire straight pin header with the TTL signals (either 3.3V or 5V depending on how your board is set up) and connect each axis to your drivers. In my case I started with the X axis which has P0.4, P2.0, P0.5 and GND (using the Smoothieboard pin numbers) and connected GND to all three of ENA-, DIR- and PUL-; connected P0.5 to DIR+; connected P2.0 to PUL+, and P0.4 to ENA+.The 4-wire stepper motor leads go on A+, A-, B+ and B-, and I ran power directly from my 24V DC power supply to the power inputs.The switch settings are just slightly confusing. You will have the Smoothieboard either configured for 16 microsteps or 32 microsteps. The entry in the switch setting table for 32 microsteps is 6400 steps per revolution. Forget about the 400, 800, 1600 numbers and just look at the microsteps to find your switch settings. Peak current for my motors is 2.8A so I selected that for current.There is ONE change you need to make in the Smoothieware config. The pin setting for direction needs to be inverted. Just add ! after it like this (for the X axis, aka alpha):alpha_dir_pin 0.5!This has to be done for each axis motor being driven by this driver unit.The Smoothieware configuration has a default of 1 microsecond for microseconds_per_step_pulse, which seems too short for this driver. It's actually just right, as observed on my oscilloscope. It comes out to around 3-4 microseconds, and this driver triggers on the leading edge, so the Smoothieware settings should not be changed.If you have dual Y axis motors, you just need to connect the inputs in series. The motors should be hooked up the same as they were when connected directly to the Smoothieboard, which often has them turning in opposite directions. In my case, P2.1 goes to PUL+ on each of the two drivers, P0.11 to DIR+ (and needs to be inverted in the config file), P0.10 goes to ENA+, and GND goes to PUL-, DIR- and ENA- on each of the two drivers.Do not use the GND from the signal header for the power connector. Both the +24V and ground should come directly from your power supply.Basically, I should have done this in the first place when putting my CNC together. These drivers are good value. There are apparently also a number of cheap knockoffs which might be slightly cheaper, but I would buy these again.

This is by far the best stepper driver I have tried on my CNC machine. It is incredibly precise while doing micro steps (at low speed it is near silent), and it also excels at high speed. In fact, it allows me to use my 4th axis add-on as a full speed lathe (driven by Teensy 4.0 at over 200,000 pulses per second), while still capable of rotating the chuck at precise angles when milling. The motor is humming smoothly no matter the speed, never missing steps or stalling. My previous driver (ST-M5045, which was more expensive by the way), driving the same motor at the same settings, was not capable of reaching 1/4 of the speed of DM542T without stalling, was not nearly as smooth or precise at microsteps, and also kept the motor much hotter, so hot in fact that at I started to suspect thermal demagnetization. Fortunately that was not the case, as DM542T had proved with gusto. The only criticism I could muster is that the driver is not completely silent at idle, there is some barely noticeable buzzing on the motor shaft if you place a finger on it. It does not transfer to the chuck which is relatively heavy. And this is my only complaint (if you can call it that). The construction is solid, the terminals are clearly labeled, and both the power and the microstep tables are printed on the cover for quick reference. Even the instruction is provided in perfectly understandable English, with all connections schematics clearly drawn.What more can I say? If you are looking for a stepper driver for a small/medium CNC machine, this is it. An example of Chinese manufacturing at its best, which reminds me of DJI-level quality.UPDATE: during the previous year, I replaced all remaining stepper drivers in my CNC machine with DM542Ts, and also replaced my old USB controller board with Warp9 Ethernet SmoothStepper to take full advantage of them. What an upgrade! Each motor can now be driven by 4 times as many pulses per second as before, and now they are not just more accurate, but also queter, cooler, faster and stronger at the same time. To increase accuracy even further, I got rid of coaxial vibration dampeners, because with real anti-resonance drivers such as these the dampeners are simply not needed. After almost a year, all five drivers continue to work flawlessly.

I put a fourth axis on my Geckodrive driven CNC router but the Geckos only do ten microsteps per full step and that didn't give me enough resolution to accurately divide the rotational axis that really didn't have enough gearing (only 3.5:1). By running this driver at 25,000 microsteps per revolution or 125 microsteps per full step I got enough resolution to make it work. Driver is as smooth as the Geckos which up till now are the best I have used. Now I can tell my 4th axis to to do 360 degrees and it actually does 360 instead of 359.5 or 360.5 which was happening with the Geckos because of their lower resolution. Also this drive clearly has some of the anti resonance measures incorporated in the Geckos, despite their seeming simplicity steppers are finicky beasts to drive well and this board nails it.Judging by how fast this driver will spin the steppers it does like the Geckos and at some point as it goes up the speed range changes from microsteps to full steps.I tried one of the cheaper TBA something or other drives and it made the motors noisy and lost steps to the point I though there was something mechanically wrong with my machine and spent days checking, tightening and adjusting everything. I wish I had bought this first.