hello
i have two stepper motors and its details are

vexta PH265b-02-a3, 2 phase 12v,0.4A / PHASE.

I AM USING 1MM PITCH THREAD ROD AND WAS UNABLE TO JOG OR TRAVEL ALONG AXIS MORE THAN 80MM PER MINUTE.IT IS MOVING VERY SLOWLY.

I AM THINKING TO INCREASE THE DRIVE VOLTAGE FROM 12V TO 24V. WILL IT DAMAGE THE MOTORS.THE CONTROLLERS ARE DESIGNED FOR MAXIMUM 36V OPERATION( A3977 -ALLEGRO CHIP) .

HELP ME TO INCREASE SPEED AND TORQUE WITH OUT CHANGING RODS..
THANK U SIR