No, that is not possible as the motor current is not continuous. Edit: Think of voltage as pressure that pushes a current through a circuit, so more voltage means more current.
I Thanks I realize thought that load is not constant, but for industrial machines for example you can put an amp clamp on the various legs of AC while the machine is in full motion to get an idea of the power draw. I was curious if there was similarly effect method for the printers. The parts that make it hard for the printer is first for DC you would need to break the circuit, second you have 4 leads, and third what would be considered full load. I was thinking (I haven't looked at the driver circuit yet) but I am guessing it draws power on one lead so you could take a measurement there. On the other hand input power and output power are not the same thing so... Just tired for all the wasted plastic on this problem and if there was a perfect solution that just took extra effort I would do it, but measuring voltage dosent seem that bullet proof.
I have used an oscilloscope on stepper circuits to look at the waveforms across the motor windings, when running, to get a view on what is happening but these modern drivers handle all the technology and take those worries away from the equation, provided they are reasonable quality devices. There is a lot of unnecessary emphasis put on this and, in my experience, provided you are in the specified voltage band, there will be no problem. If you are unsure, just swap a couple of drivers around and see I your problem moves as well but most problems come from poor alignment and over-tight belts that put unusual loads on the motors. In the case of the extruder I would want to check the tension, hob teeth and the free movement of the hob bearing after checking the filament path through the nozzle assembly.
I just can tell from my own experience, I ordered some replacement stepper drivers as a backup and I was not able to get the exact ones I have from E3D anywhere... So I got some which had the same chip and looked much the same, but they have to be mounted 180° turned on the Z axis. And the voltage values are different because of a different resistor... There was some docs for those drivers and the voltage I had to set to get them working was almost doubled the values to set for the ones I got from E3D...
I have three different drivers with the same chip from different manufacturers and the spec is the same for all of them but, as Alex implied, the spec sheets are important and not always available from Chinese suppliers. I would assume that BigBox has a singular source so will have set their voltages on those specs.
I received my new drivers from pololu so they should be fairly garenteed quality, wasn't sure where to get the original big box drivers either
That was so long ago I can't remember the end result, I think it wasnt long after that, that I switched to the duet board. That said I think I ran with the pololu drivers without an issue for a short time.
