High power driver failure

Well, turns out it was a bad 4 slot wire terminal(green) that was the culprit. 1 of 4 wires popped out. Turns out the terminal was bad from the factory. It felt tight but was not tightening all the way. Kudos to Jake, they are sending me out a new terminal block.


Which one did u get on Amazon? I was not able to find an exact clone? Any link?

The large driver is a CWD860H. You can find them on AliExpress and sometimes Amazon.

There are much better stepper drives available more easily and for less money. I switched to Leadshine EM542S which are $50 each from Automation Direct. They run silently, keep the motors cooler, and don’t have the resonance of the stock drivers. There are cheaper Leadshine drivers like the DM542T that might also work. Amazon has those branded as StepperOnline for $21. I can’t say it’ll be an improvement because I haven’t used it, but I bet it will be.


Anybody find the stepper motors on amazon…id like to get a spare one of those too.

You can get it from Langmuir. This way it has the cable connected to it. They do not
Mark up their parts very much.

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Alex are there any big differences between the EM542S and Langmuirs? Are the dipswitches all set the same and easy bolt in?

It’s pretty easy to swap in, but you need to swap the pins around if you have the “small” drivers (TB6600). Langmuir documents the pin swap because you need to do it going from “small” to “large” drivers.

Otherwise you need to pick max motor amps and make sure that the microstepping is set to the same setting (1600) for it all to work. Also make sure the driver is switched for 5V signaling (Leadshine has them defaulted to 24v).

Hi guys, I apologize for not understanding this but is CWD860H the actual updated driver that Langmuir sells?
The reason I ask is I found them on ALI for $35 plus $20 to ship. Says they are the same thing and will have them in 14 days. Now I don’t have them yet but I thought I would try for $150 and see what happens. If they work, I will be happy and get a few spares. What sucks is you have to buy them 1 at a time and if you try to buy 3 together the shipping is like 250$.

CWD860H Stepper motor Driver 0-7.2A 60-110vDC / 40-80vAC for Nema34 motor Digital stepping driver - AliExpress

That is the product code that was on mine.

There are better stepper drivers available more quickly if you are going to upgrade. I’m using Leadshine EM542, but there are a lot of options out there.


Would you mind sharing wiring and pin settings for the 542 stepper driver? Wound these be wired following the same instruction for the high power driver swap in the langmuir manual?

you should dig around there is likely more than one seller

Hi Alex,
I completely agree but my problem right now is I am having serious odd issues. Langmuir has dragged their darn feet so long I am out of patients and I need a plug and play solution.
If these do not work then I will try and order the 542. I am not an Ali fan and these might not even come. Is there is anyway possible for you to put a pin-out and wiring on here or are you aware of a link to what you might have used? Looks like some others are looking to give this a shot as well.

The pinout is shown directly on the drivers and the EM542 that I mentioned.

On the EM542 you need to set the following dip switches:

  • 5v signaling (this one is on the side)
  • 1600 steps per revolution
  • 4.2A
  • Smoothing time: 12ms
  • No auto tuning (I had bad luck with it)
  • Control mode: step dir
  • Default everything else (off)

This is what the drive looks like, as you can see it is self documenting:

Here is a CWD860H:

You’ll need to swap PUL and DIR pins, high voltage pins are the same. Langmuir doesn’t hook up the ENA pins. Power supply may need to be swapped (my MR-1 has black for 36V, white for ground – very weird for DC).

The EM542S is slightly smaller and you either need to drill a new mounting hole or make an adapter plate (I did the latter).


Your an absolute blessing!! Thank you Alex!!

Hi Alex,

Believe it or not those drivers came from China in about 10days.
I have a question. I opened the cabinet and noticed I have one upgraded driver (assuming) z. Unfortunately this is the driver I seem to have issues with so should I swap this with a new driver to see if anything changes?
Are you aware of any documentation for these new drivers on installing them? I don’t see anything on them.

Is this swap for the Langmuir 860H drivers?

Follow the phase wires from the driver to the back of the machine to see if your current large one is on X or Z. Langmuir has shipped them both ways.

There is some guidance from Langmuir here on swapping drivers:

The documentation on swapping drivers is here:

All of the drivers have documentation for the pins printed right on them. Take a photo of how it was wired before you start moving pins around in case you need to check what color wire had which role.

Good luck, hope the driver upgrade fixes your issues.

Wow you are correct that is on the X not the Z. Cant keep up:)

This was a bit intimidating at the start but I get it now.

Me to. I am keeping my fingers crossed and hope the control board fixed most of them.
Thanks again.

Hey I know this is an old thread but I’ve got a question. I Converted my X and both Y Drivers to the leadshine em542s and I’m having an issue. they are working but its like they’re overpowered and this noise in the ballscrew or motor kind of ramp up until they stall. the X does it worse and the Y will do it occasionally. any thoughts on something I missed. I believe I have everything set the way it should be. Thanks in advance!

How are yours configured? There is a switch for “auto tuning”, try flipping it to the other setting.


Ahh that was it. I saw where you said don’t do auto tuning but didn’t see that the setting said no auto tuning. So by having that disabled I actually have auto tuning on. That fixed it Thank you!