Can anyone provide any insight into setting the current for stepper motors?

3D Printing
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1

Can anyone provide any insight into setting the current for stepper motors? I have a Rated Current/Phase of 1.5A for the extruder
And for the X, Y, Z Rated Current/Phase is 2.8A

2

It really should be explained better in the file because it isn’t what you think. I believe the drivers can only handle 1.2 amps (not sure) and it isn’t a one to one current setting. I think it is RMS or half the current because .5 works just fine where I would normally use 1.2

3

With the drivers max of 2.5A but RMS is 1.2A, your are saying the max value in the config files should never be above 1.2? and the value you are setting in the configuration file is the current/phase value of the motor in question. Thanks again for the information.

4

The question should be answered by Elias. I’m just saying from what I can tell by a few comments and from the fact that if I use more than .5 my motors get really hot when I would typically use more than .5 on other drivers.

5 
def set_current_value(self, i_rms):
    """ Current chopping limit (This is the value you can change) """
    self.current_value = i_rms
    
    r_sense = 0.1020              # External resistors + internal
    sqrt_2 = 1.41421356237

    v_iref = 2.5*(i_rms/1.92)
    if(v_iref > 2.5):
        logging.warning("Current ref for stepper "+http://self.name+" above limit (2.5 V). Setting to 2.5 V")
        v_iref = 2.5
    logging.debug("Setting votage to "+str(v_iref)+" for "+http://self.name)
    self.dac.set_voltage(v_iref)