Doubt regarding adjusting 5 differents drv8825 potentiometers simultaneously

Other Hardware Motors, Mechanics, Power and CNC
1

Hi
I'm not sure if this is the right subforum

I have the following things:
-12v 15A power source
-Arduino Mega 2560
-Ramps 1.4

  • 5 Nema 17 Stepper motors
    Series Model : T42H47-1684
    Motor Length : 47 mm
    Ph. Current : 1.68 A
    Ph. Res. (Ohm) : 1.65
    Ph. Inductance : 2.8 mH
    Holding Torque : 4.4 Kg-cm
    Detent Torque : 200 g-cm
    Rotor Inertia : 68 g-cm2
  • 5 DRV8825 stepper drivers

If I look at the drv8825 datasheet, the voltage on the drivers should be : I phase motor = 2Vref -->
1.68= 2 Vref --> Vref= 0.84 V

So, If I put my stepper driver where it goes regarding the Z axis ( please have a look at this image)

And I set the voltage to 0.86V (using a mutimeter between the black wire on the left, and the driver's potentiometer) everything's good.
Now, if I disconnect that very same stepper driver and put it in another place, the voltage is not the same (0.86V) and I have to readjust it.

My question is: If I'll be having 5 stepper motors with 5 stepper drivers.... all of them should have 0.86 V.
should I connect them all and adjust their voltage one by one? in any specific order?

2

Everything has tolerances. Particularly things electrical. Connect the driver to the motor it will drive and then adjust it's pot. Then you will get optimum performance from each set. Same for each set of devices. The order has no bearing.

I sure hope you are turning off the power before disconnecting/connecting stuff!

Paul