The first time I started my A350, I heard what seemed like a fan running inside the enclosure (not the enclosure fan). It was a slight humming sound. I deduced it could be the stepper motors engaged. So I tried sending M84 to the machine. Bingo! The sound stopped. I wanted to make sure it didn’t conflict with other processes so I ran a Home command. Not issues. the machine went to the Home position without issue. However, the stepper motors remained engaged.
Why would the steppers remain engaged if they are not being used?
Could this be a contributing factor to the linear module issues?
I’m still pretty new here so I don’t know who to tag in development to see if this makes sense.
You know how when the machine is off you can push the carriages around? If you turn the steppers off you can plan on gravity moving the Z axis down a bit, and any small bump will move the axes.
As you mentioned, this is not an issue if you turn the steppers on and then home. But if you turn the steppers on and then move the head without homing it will think it’s somewhere else, and can risk crashing the head.
The only way to provide any holding power against unwanted moves is to drive the motors with current so they have holding torque. A disabled stepper motor has no resistance against turning.
So typically steppers are left on unless you specifically don’t want them to me.
I programmed a previous machine (running Repetier firmware) to turn the steppers off after 20 minutes of inactivity, and then when any new serial connection it would automatically re-home.
This is something the firmware could have improved. Disable the steppers after long periods of inactivity, and then rehome when they need to become active again.
My A350 made a nasty noise whenever I would try the home the system. Turned out that the cable to the heated bed was getting caught on the right Y axis linear rail and preventing the bed from completing the move to Y=0. After rerouting the cable (and making an end cap to keep the cable from snagging) my issue has disappeared.
Exactly as @brent113 said. You can’t rely on the steppers position if you don’t hold them steady into the last known position by the software.
It would also be very useful to have a firmware-side automatic stepper disengagement option to avoid the steppers to remain engaged (sometimes hours) after a printing is finished.
I think editing the gcode everytime it’s not really an option for the common user, especially if you’re going to upload wirelessly. A switch would allow the user to have it permanently.
Thank you for the link to the command page, it would be awesome to be able to also specify a timeout.
For those of us using Cura, Simplify3D, and other slicers that have custom start and end gcode, that’s a very good option. Just stick it in the start gcode with a timeout, or the end gcode after the typical home command to home and shut off.
I agree with both sides… its easy to add with custom end codes… but every other 3d printer i know of has the option to turn them off from the controller.
I have a completely different issue. I have M84 in my end G-code (from Cura) but the command is being ignored by the printer after the job completes. Furthermore, when I use Luban to connect via wifi and send the M84 command in the terminal, it gets ignored then too. Anyone have ideas on that???
Thanks. M18 also does not work for me. Yes, all caps. M84 and M18 don’t turn off steppers for me. I’m in Luban, connected via wifi, and using the Console. I get “OK” but the steppers do not turn off.
That’s not good… That must be related to the other issues the developers have been fighting. If you can find a away to reproduce this the developers might like to know on GitHub
