I recently got a Pololu DRV8825 stepper motor driver to drive a high powered stepper motor (datasheet attached), which will be used in conjunction with an Arduino Leonardo.
On the Pololu website, the following warning appears:
Warning: This carrier board uses low-ESR ceramic capacitors, which makes it susceptible to destructive LC voltage spikes, especially when using power leads longer than a few inches. Under the right conditions, these spikes can exceed the 45 V maximum voltage rating for the DRV8825 and permanently damage the board, even when the motor supply voltage is as low as 12 V. One way to protect the driver from such spikes is to put a large (at least 47 µF) electrolytic capacitor across motor power (VMOT) and ground somewhere close to the board.
This got me to thinking: Are there any best practices in the physical placement of stepper motors and their drivers and the controlling micro-controller? For instance:
A stepper motor can have quite a strong magnetic field when powered, particularly if it is larger motor. Should a minimal distance from the motor to the motor driver be maintained to prevent magnetic interference?
Is there a point where the leads from the motor controller to the motor would become too long?
Regarding the distance of the motor driver to the micro-controller: Is a shorter distance preferable?
I realise this is a rather nebulous posting, but I’d appreciate any kind of feedback from those who have “field” experience in this before finalizing my project.
D310454D.PDF (522 KB)