Weird stepper motor behaviour on RAMPS in arduino Following this tutorial:

http://www.instructables.com/id/Complete-newbie-step-by-step-3D-printer-with-all-p/?ALLSTEPS

I connected DVD stepper motor to RAMPS 1.4 on arduino with Marlin software with this settings: 

 //#define DEFAULT_AXIS_STEPS_PER_UNIT   {80,80,4000,500}  // default steps per unit for Ultimaker

 #define DEFAULT_AXIS_STEPS_PER_UNIT {215.12,215.12,8034.69,196.52}

 // #define DEFAULT_MAX_FEEDRATE          {300, 300, 5, 25}    // (mm/sec)

 #define DEFAULT_MAX_FEEDRATE {100, 100, 2, 25}

 // #define DEFAULT_MAX_ACCELERATION      {3000,3000,100,10000}    // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.

 #define DEFAULT_MAX_ACCELERATION {200,200,50,5000}


 #define DEFAULT_ACCELERATION          100    // X, Y, Z and E acceleration in mm/s^2 for printing moves

 #define DEFAULT_RETRACT_ACCELERATION  100    // E acceleration in mm/s^2 for retracts

 #define DEFAULT_TRAVEL_ACCELERATION   100    // X, Y, Z acceleration in mm/s^2 for travel (non printing) moves


I put a video at vid.me (hopefully with sound) showing stepper behaviour when I press +1mm,-1mm,-1mm,-1mm,-1mm,-1mm,-1mm,+1mm,+1mm,+1mm,+1mm  on Pronterface software.
The video you show shows movement of far more than 1mm.  This indicates that the steps per unit is far different than you are configuring the Marlin software for.  With a +/-1mm and 212 steps per mm, there should have been 212 steps sent to your stepper.

Recalculate your steps/mm values and slow down the feed rate to get something reliable.  

For experimenting, in Pronterface, set the feedrate of 10mm/sec (600mm/min) or 1mm/sec (60mm/min) to slow things down so you can hear or count the steps with your ear, then choose smaller steps, like +0.1mm and see if you get the planned displacement.  If, at a really slow speed, you don't get the corresponding movement, then your steps/mm need adjustment to match your system.  

Eyeballing it, I'd say the called-for 1mm or 212 steps is moving the stage about 10mm, so you would need numbers more like this for the x and y axes:

#define DEFAULT_AXIS_STEPS_PER_UNIT {21 ,21 ,8034.69,196.52}