Hello,
I am driving a Nema17 2A 17HS19-2004S1 with a a4988 driver on a CNC shield.
It's for a robot's arm joint so i need the stepper to have the maximum torque all the time, even when stopped.
I wanted to know if the a4988 driver limits the output current to the motor when idling (like reducing by 50% like other drivers do, for example DM542T has the option). If so how to disable this option.
By the way the only option i have on the driver to set the output current is potentiometer ? I need to set to 2Amps then.
A4988 :
Stepper :
https://www.omc-stepperonline.com/fr/nema-17-bipolaire-59ncm-84oz-in-2a-42x48mm-4-fils-avec-1m-de-cable-et-connecteur-17hs19-2004s1?srsltid=AfmBOor6RkLECpF04eFy4hcKxSsT0ySeE9D-mls9ZoozcOCcJ8WRJivp
The A4988 is not suitable for that motor, as it can handle at most 1 Ampere per winding, at half the rated torque.
Buy a driver that can easily handle more than 2 A per winding.
1 Like
So here +/-2A is IN TOTAL ? for both windings.
That is the absolute maximum current. Never operate devices at or above their absolute maximum rating.
With the A4988, if the steady state current exceeds about 1 Ampere per winding, the motor driver will overheat and shut down.
To do that requires maximum voltage that the controller can handle. Be sure to mount the stepper motor in metal that can help to dissipate the heat from the motor.
Which one is suitable then ? DM542T ?
Any current limiting stepper driver than can easily handle more than 2 Amperes per winding should be fine. Do your research!
Any stepping motor provides the maximum holding torque when it is stopped. It often surprises people to know that a stepping motor draws maximum current when it is stopped.
Any movement of a stepping motor causes the current draw to reduce.
