Motor Shield heating and Stepper Motor 'stepping' and not rotating

I have a Adafruit compatible motor shield v2 on Uno connected with 1.8degree/steps motor, when i power the Uno with a 12V 2A with jumper on, the stepper start to rotate but then it will start 'stepping' and not rotating smoothly. What is the cause? I can feel the driver is also heating up.

However, if were to start powering just with USB on the Uno, the motor will rotate smoothly but will ran out of power and stop. LED is off.

Any help will be appreciated.

Have a look at stepper motor basics.

Post a link to the datasheet for your stepper motor

...R

My motor is Wantai 42BYGHM809. Here is a link

I have also tried on 1.8 steps and 1.5A motors with the same ‘stepping’ issue which I think is a over heating issue.

I will read up on the motor basics

That motor requires 1.7amps per coil. I would suggest using a Pololu DRV8825 driver board.

…R

tiguu:
My motor is Wantai 42BYGHM809. Here is a link

http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Robotics/42BYGHM809.PDF

1.8 ohm motor - you must use current drive (chopper driver), not voltage drive
(H-bridges). If the motor was more like 30 ohms then voltage drive would make
sense, but low impedance motors are high performance and mandate current
drive.

The first rule in stepper motors is to know the difference between low impedance
(bipolar, current control, high speed) and high impendance motors (voltage control, much
slower, usually unipolar).

thanks. I looked like I need a different stepper motor.

You say that it starts to turn but then starts "stepping" is that correct? If you get a few smooth steps but then the performance gets worse it could be a sign of too small power supply. What kind of power supply are you using?

Also I agree with the other posts about the motor current and coil resistance. 1.8 Ohm is a very low value indicating that a regular H bridge will have some difficulty driving it properly.