Stepper motor doesn't work

Hi,
I have some problem with my stepper motor. Some background:
Prusa i2
Marlin
Pronterface
Arduino mega clone + ramps 1.4 + stepstick
First I download marlin and begin to test in pronterface, but motor doesn't turn. It vibrate and make different noise. Then I use ramps test code. Motor began to turn but sometimes it stop, it seems to me like something blocked it( I didn't attached motor to printer.)I have tried different curent by pot.
Anyone know how to solve that problem?

Update: I managed to use motor with test code, but in marlin it doesn't work. It turn when I command 0.1, but in bigger value, like 10, only noise.

hi friends,

the stepper motor need 5amp...

if a 11amps is given to the stepper motor wat wil hapn to the motor does it work or?

karagad

lower your feed rates. default feed rates in pronterface are far to fast, and you havent set feed rate max's in the firmware yet to tell it to ignore overly fast feed rate requests.

jeeva djiva

Amps are pulled not pushed. Thats what the variabe resistor on the pololu sets, how much amps its allowed to pull.
If you set it to high the driver wil over heat and shutdown, or if it way to high they can die.

It turn when I command 0.1, but in bigger value, like 10, only noise.[/quote]

0.1 what is this ? where it is in marlin ?

@karagad what actually "command 0.1" means ? where this value is in the marlin ? please help !!

Hi, it is from pronterface. 0.1 mean "to move 0.1 mm."