HDD Step Motor.. Please Help

I have a stepper from a WD800BB hard drive which runs at 7.200 rpm.
My problem is that i use it with 9v which is enough i think, through a H-Bridge… but i cant get it to get max speed… i think its cause i assuming the total steps, but i can’t find anywhere the specs from that stepper.

Have anyone used a HDD stepper?? Any direction for the number of total steps…?

Forgot to say that i am using it with <Stepper.h>

Thanks,

I doubt that it's a stepper - rather, it is likely a BLDC motor (brushless DC 3-phase). You can treat it somewhat like a stepper, but you'll only get the slow speeds you're seeing. If instead you drive it like a 3-phase/BLDC motor, you'll likely have better results.

You can use the 3-phase BLDC motor from a harddrive, using a ESC (Electronic Speed Controller) used for RC hobby motors, they are usually BLDC motors too.

If your motor has 3 terminals, just wire them up, to reverse the direction, swap any two conductors, and it will reverse it's direction.

If you have a motor with 4 terminals, measure the resistance between them, to figure out the center tap. You do not want to use the center tap with a ESC. The one connection with the lowest resistance to the other three is the center tap.

ESC's can be had for almost no money and you control them just as a servo motor.

The cheapest i could find on eBay: http://www.ebay.com/itm/10A-Brushless-Motor-Electronic-Speed-Controller-RC-ESC-airplane-/400242927726?pt=AU_Toys_Hobbies_Radio_Controlled_Vehicles&hash=item5d3056686e#ht_1780wt_1180

// Per.