Enable steppers at power on

Mostly Printed CNC - MPCNC Troubleshooting
1

Is there an option to enable the steppers at power-on of the MPCNC using a Rambo-mini?

Currently I’m using the LCD to move the router to the correct position and reset the coordinates from the V1 menu. But at that moment the steppers are still not enabled and can move before I start the cutting my project.

2

I am a bit confused about your setup process. The steppers are enabled the first time any electronic movement is made. They are not disabled unless 1) the timeout expires for the steppers, 2) they are told to disable, or 3) you power down the electronics.

You can explicitly engage/enable the steppers using an M17 g-code command.

You can explicitly disable the steppers using an M18 g-code command. M18 can also be used to change/extend/disable the timer used for disabling the steppers.

The default timeout for the V1 maintained versions of the Marlin firmware is 20 minutes. I don’t think the timeout is your problem here, but if you want to adjust it, you can make changes in this section of configuration_adv.h:

/**
 * Idle Stepper Shutdown
 * Set DISABLE_INACTIVE_? 'true' to shut down axis steppers after an idle period.
 * The Deactive Time can be overridden with M18 and M84. Set to 0 for No Timeout.
 */
#define DEFAULT_STEPPER_DEACTIVE_TIME 1200 // 120

Your issue doesn’t sound like it happens at the end of the job, but if it does, take a look at your settings in whatever you are using to send the g-code to the control board. For example, this setting in Repetier-Host Printer Settings, when enabled, automatically kills the steppers at the end of the job:

image

Edit: if you really want to engage the steppers on power up, and you have a display with an SD card slot attached to your machine, you can put an M17 in a file and use Marlin’s Autostart feature.

3

Thanks Robert,

Will give the auto start option with M17 a try as that looks like the easiest solution.

4

When you author the file, make sure you put a newline at the end of the line. Last time I checked, if there is not a newline at the end, Marlin ignores the line. This is true for any lines authored, not just a M17.

5

Interesting! So you can use the autostart feature to, say, have the machine run a startup routine as soon as you power on? This would be hella helpful in my setup.

6

I tested Autostart a year ago when I first read about it, and yes, it runs when the machine is first turned on. It does require “native” SD card support. It works on Rambo boards with a reprap 12864 display. It should work on an SKR Pro as long as you have the cables attached that allow the display to be put in Marlin mode.

1 Like