Motors turning off after slight rotation

I just started out with my smoothie board. But I am having some bizarre issues right from the start :frowning:

When I applied the 24V rail and send M17, ( I only have the first motor connected currently on M1) I can hear the motor buzzing. So it has power. Using pronterface I just clicked the X axis and the motor rotates the few degrees then just powers of completely. The only way I can get it to enable again is to power cycle the 24V rail.

It also does the same if I unplug the stepper motor, and plug it back in again, there is just no way for it to enable again without power cycling the 24V rail.

Is this supposed to happen ? I do not really see what I am doing wrong.This is some bizarre protection feature, can it be disabled ?

I’m using the latest confirm file and firmware.

Are you unplugging and plugging the stepper motor with power supplied to the board?

24V yeah.

Have to type 10 characters else won’t let me post :-\

Seems I have to send M121 to keep the motor alive. Though while the motor moves, its “ticking” and doesn’t look like its moving smooth. not 100% sure the wiring is right, but think so.

ahh so 1.5A is causing the motor driver to overheat and shut down :-\

So I sent M907 X0.5 Y0.5 Z0.5 E0.5

and I see 300mA on my PSU at 24V.

If I reduce to 12V then I see 0.5A as expected, but then 0.6A sent, PSU now reads 0.68A… So something not right there :frowning:

Disconnecting stepper motors with power applied can very easily damage stepper drivers. Plenty of stepper drivers have been destroyed because a wiring harness had a bad connection and it was effectively the same thing.

I’ve done a test script for the X motor (M1) in case anyone else has this problem while getting started.

This will set the motor current to 0.5amps for a Nema 17 38mm and also pin the motor at various speeds. It seems the default profile uses 1.5amps but this does not seem to work as the driver overheats and shorts down at over about 0.8amps. The no idea what is going on there as previously mentioned.

M907 X0.5 Y0.5 Z0.5 E0.5 
M92 X88.91 Y88.91 Z400.00 E88
G0 X200 F1000
G0 X300 F2000
G0 X400 F3000
G0 X500 F4000
G0 X600 F5000
G0 X700 F6000
G0 X800 F7000
G0 X900 F8000
G0 X1000 F9000
G0 X2000 F10000
G0 X3000 F20000
G0 X4000 F30000