Longtime lurker / reader / hobbyist... first actual post.
I am working on a project using Pololu DRV8825 stepper motor drivers, enclosed in a metal project box, powered by a 2-wire external 12V DC "soap-on-a-rope" type power supply. The installation involves a lathe that has a high speed urethane belt driving a cutter, which is independent of the stepper controller, which is driving the spindle at slow speeds.
Twice now I have had a DRV8825 driver fail, in a similar fashion. It is leading me to think that there might be an issue with the urethane belt, which seems to generate a lot of static electricity. Perhaps being near the belt and touching the project enclosure allows the static electricity to fry the DRV8825 stepper driver somehow?
My question is, is there some proper way to ground a metal project enclosure, when the only wires coming to it are the + & - from the DC power supply? (Meanwell GS60A12-P1J) Or is there some other "best practice" to protect a circuit and enclosure in a potentially high-static environment, where the only power is from the DC supply?
I did try to connect the negative / ground of the DC side, to the case as an experiment, but same results. The failure mode for the DRV8825 seems to affect the step-size portion of the driver, e.g. the driver randomly goes into a different microstepping mode from the way it was hardwired (before it quits altogether).
A pic is attached of the simple enclosure, with power jack for the DC supply, USB port (used only when programming), and two motor jacks. Buttons for each motor are "run", "stop" and "direction", along with an encoder to vary the speed. Nothing really complicated. I don't have a schematic, as this is just simple breadboard point-to-point wiring between a Teensy 3.2, a buck converter, conditioning capacitors and the stepper drivers.
Any insights appreciated, thanks.
I am working on a project using Pololu DRV8825 stepper motor drivers, enclosed in a metal project box, powered by a 2-wire external 12V DC "soap-on-a-rope" type power supply. The installation involves a lathe that has a high speed urethane belt driving a cutter, which is independent of the stepper controller, which is driving the spindle at slow speeds.
Twice now I have had a DRV8825 driver fail, in a similar fashion. It is leading me to think that there might be an issue with the urethane belt, which seems to generate a lot of static electricity. Perhaps being near the belt and touching the project enclosure allows the static electricity to fry the DRV8825 stepper driver somehow?
My question is, is there some proper way to ground a metal project enclosure, when the only wires coming to it are the + & - from the DC power supply? (Meanwell GS60A12-P1J) Or is there some other "best practice" to protect a circuit and enclosure in a potentially high-static environment, where the only power is from the DC supply?
I did try to connect the negative / ground of the DC side, to the case as an experiment, but same results. The failure mode for the DRV8825 seems to affect the step-size portion of the driver, e.g. the driver randomly goes into a different microstepping mode from the way it was hardwired (before it quits altogether).
A pic is attached of the simple enclosure, with power jack for the DC supply, USB port (used only when programming), and two motor jacks. Buttons for each motor are "run", "stop" and "direction", along with an encoder to vary the speed. Nothing really complicated. I don't have a schematic, as this is just simple breadboard point-to-point wiring between a Teensy 3.2, a buck converter, conditioning capacitors and the stepper drivers.
Any insights appreciated, thanks.
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