Using CD/DVD drives with ramps 1.4

I am trying to use recycled DVD steppers with a ramps 1.4 and am having a few problems with the motors. The motors shake around and are very jumpy when using repetier control. They also get very hot to the point where they burn me. I am using the potiometers on the board but moving the screw around dosent seem to help. I am thinking the pots might only be limiting current and the voltage is too high, if so so how would I step the voltage down from the 12v the atx PSU I am using is providing? Any advice?

I've used them very succesful in my toy laser-engraver.

// default settings

#define DEFAULT_AXIS_STEPS_PER_UNIT   {106.67,106.67, 4000.0, 1000.0} 
#define DEFAULT_MAX_FEEDRATE          {40, 40, 4, 250}    // (mm/sec)
#define DEFAULT_MAX_ACCELERATION      {900,900,100,10000}    // X, Y, Z, E maximum start speed for accelerated moves. 

#define DEFAULT_ACCELERATION          300    // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION  3000   // X, Y, Z and E max acceleration in mm/s^2 for retracts

// The speed change that does not require acceleration (i.e. the software might assume it can be done instantaneously)
#define DEFAULT_XYJERK                2.0    // (mm/sec)
#define DEFAULT_ZJERK                 0.4     // (mm/sec)
#define DEFAULT_EJERK                 500.0    // (mm/sec)

Edited 1 time(s). Last edit at 01/15/2018 03:07AM by o_lampe.

The pots on the stepper controllers adjust the bias current, which probably needs to be quite low for the DVD stepper motors. You'll want to adjust these down, but I'm not sure what values you'll want to use. Probably if the motors are getting too hot to touch, they're not going to be very happy.

If you're using an ATX PSU, you might consider using the 5V power rail for your RAMPS input for the stepper motors, unless you need 12V for other motors?

I am using Nema 17s for the Z and E so I assume they will need more, also I think my hotend will need more .

You might have toasted the steppers already, check the coils for continuity.
IIRC, my DVD steppers can take 100-250mA. Each driver has it's own formula to calculate Vref.