Nema 34 stepper motors

Does anyone know if the X Controller drivers can run Nema 34 stepper motors

We’d need to know the power specs of the proposed steppers in order to accurately determine the answer to that question.
The NEMA numbering system is a spec of the mounting pattern of the face of the motor, the 34 indicates that the face plate size is 3.4" x 3.4" but there are many different options for power specification for voltage and current draw.

However, generally speaking, the smaller Nema34’s run at 4 amps and the MAX setting for the drivers in the X-Controller is 4 amps. so the drivers would certainly work more than normally and you might want to add another fan to ensure the drivers stay cool…

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Thanks Seth
You have answered my question, the MAX settings in the X-Controller is 4 amps, I have not done any research yet about the different types of Nema 34, I was thinking it might be better for my setup, as I am having a grinding noise at the moment, I need to adjust my GRBL settings for acceleration, and feed speed, I remember reading somewhere about the Nema 34 being the best choice for acceleration problems, I will try reading more about this.

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I have been playing around with my GRBL settings to get the feed rate right and the acceleration, I can get the X axis to 1800.000 mm/min which suits me fine, but on the Y axis I can only get 700 mm/min before it starts grinding or seize up, I just do not understand why they should not both be the same, they have the same Nema 23 motors

do they both use the same gear ratio?
Also the feedrate is also effected by the microstep setting on the controller (if yours is selectable, the X-Controller is via the dip switches)
Also you might want to test one side at a time to ensure both sides are actually driving, It is quite easy to burn up one of the Y axis drivers; moving the gantry front/back by hand will generate voltage and backfeed to the drivers and they will burn up if this action is done quickly before the drivers have enough time to dissipate the voltage through heat, so make sure to not ever move the gantry around manually by hand… but also unplug one side and jog it, and repeat with the opposite side plugged in and you can verify that both sides are actually driving properly…

Side note about the nema34’s: If you go this route I suggest using a larger gauge wire for the cables as well if you do this upgrade since you’ll he on the top edge of the drivers output… you can find some basic resistance calculators over on cable suppliers website to help explain this more, but the smaller the wire gauge the more resistance there is in the wire itself, using a larger gauge will allow more power to reach the stepper, so on my setup which uses some drivers that output 2.8Amps max and my nema 23’s are 2.7A I was getting some voltage drop that effectively cause less wattage to even reach the stepper, so by upgrading from 24AWG wire to an 18AWG wire i was able to change a 3V drop into like a 0.5V drop giving my steppers a considerable amount of additional strength, and I just so happened to have the wire sitting on a shelf anyway…

Thank’s Seth,
I figured out why the X axis is moving better than the Y axis its because the X just has the spindle to move and thy Y has the extra weight of the gantry plus the spindle,
Thanks for the tip about the larger gauge wire, if I did go for 34 Nema’s would it be best to change all 4 or just on the Y axis, also how do I find out what current I am using at the moment,
My steppers are Nema 3.1Nm =439 oz/in and I have no idea what micro stepping I am using, I will need to have a look inside the X Controller

it looks like those steppers might be 3 Amps max current…
so you’d want to adjust the potentiometer to achieve that output from the drivers…
The “pointer” is the line between the 2 dots, so the default setting from the factory is 2.4A output.


These charts correlate to the micro-stepping and the current outputs and Each of the 3 Axises have their own settings.

As for the wires, I would upgrade them all if you’re already there, The X and Z use the longest run of wire so they’d experience the largest drop anyway.

Thanks for all your help Seth, I did adjust the potentiometers, I found it very hard to see them even with a magnifier, I also checked the wiring that I bought when I did the last upgrade and found it is 18AWG so that should be okay, it is running a lot better than it was, I am still fine-tuning the Y axis in GRBL , I think I will study some more and probably get a better controller before I upgrade the stepper motors, I will have a look at what controllers are about

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Ohh i forgot one more thing… look at the above photo, within the rectangle of the dip switches, see switch #4 at the very bottom, this is a “power savings” sort of setting I suggest switching all of the #4’s to off position which give the steppers more strength during idle, so that the gantry holds even tighter during the bit swaps…


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Thanks, Seth, I will do that

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