Z motors stays on after M84
Hello
My end script includes M84, it turns off x, y and e axis, I can freely turn them by hand,
But after M84 both Z motors are left on (on = hot and very difficult to turn shaft by hand).
Only when I power printer down, both z motors are powered down and can be easily turned by hand.
I believe this is bug (unintended feature) as sometimes after print is done, printer stays on, and motors are overheating.
Anyone else seen this?
//environment
Prusa i3 MK2 kit upgrade form MK1
Firmware 3.0.5 RC
Simplify 3D 3.1.0 with latest Prusa profiles
No other issues, printing perfectly
//my end script
M104 S0 ; turn off temperature
M140 S0 ; turn off heatbed
M107 ; turn off fan
G1 X0 Y200; home X axis
M84 ; disable motors
Re: Z motors stays on after M84
Janis
It is not a fault in the firmware; it is actually by design to prevent accidental movement of one of the motors leading to misalignment of the X axis
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Z motors stays on after M84
I understand this intent, but I'd love to prolong the lifespan of the motors. Is there G-code for turning off Z motors?
Or the only option is complete power-off?
Re: Z motors stays on after M84
You could try M18, but I don't know if it will work. The only other option is to amend compile and upload your own firmware.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Z motors stays on after M84
Yeah I noticed this as well.
Seriously, if I issue gcode that says, "Disable all steppers", it should do it. That's just a bug.
That's like putting the power switch on the printer, but not wiring it up. "Yes, we know you wanted to turn the printer off, but we want to make sure your gantry stays level."
I currently have my printer on a wireless power switch and I just turn the entire thing off when I'm not using it.
Re: Z motors stays on after M84
Yes, I would agree that it can be classed as one more design fault, much like the G28 (or G28 Z) command which sets off a 9-point probe calibration, whereas it should home Z.
Unfortunately, Prusa Research are redefining the standard Marlin GCodes.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Z motors stays on after M84
Oh jeez I just noticed that, thanks for pointing it out.
That's just awful.
There's no reason to be unilaterally breaking compatibility. Even M84 accepts optional parameters if you really want to not have it turn all the steppers off. This is just bad decision making.
Re: Z motors stays on after M84
More power to Prusa Researches elbow. Breaking the mould and moving on to better things. Change is good, thats why we Brits voted for Brexit. New free thinking and choice apart from the EU dictatorship and petty rules. The nanny European Project is a failure to govern and tell us what to do by unelected EU officials, ie the EU president and their other unelected officials. Not democracy.
Marlin can be changed for the better. I run a 3D printer originally based on Marlin. Not a Prusa I3 and went for something better, based mostly on Marlin, but better. On a 32 bit board. This board could drive a Prusa I3 easily.
Nigel
Life is keeping interested and excited by knowledge and new things.
Re: Z motors stays on after M84
I'm sorry, British humor sometimes eludes me.
Regardless, the correct thing to do is use "M18 X Y E" or something if that's what you really want, instead of butchering the firmware to produce unexpected, non-standard behavior.
I looked at the gcode, and this is what came standard in my profile:
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G80 is supposed to be "Cancel Canned Cycle (CNC specific)"
If you want to do a more detailed probe, that's what G29 is for.
The reason why this matters is if you try to do the sane thing, which is put a frontend on the machine like OctoPrint. If they choose to expose a "turn off stepper motors" or "detailed z probe" button in the software, now if it really wants to do what the user asks for, it has to know whether or not it's talking to a Prusa mangled firmware whereas if they just followed the existing conventions, everything would just work.
This is the first printer that I've been using without OctoPrint and I have to say it's been a pretty miserable experience. Just set up a new Raspberry Pi though.
But now I question if the Prusa firmware is going to do the right thing when I try to use OctoPrint. What other unnecessarily out-of-spec surprises await?
Re: Z motors stays on after M84
Yep. Hooked up OctoPrint to the I3 tonight.
Pressed "Home".
The thing did the full 9 point probe instead of just going home.
Re: Z motors stays on after M84
gz1
Yes, I have already had discussions with PR tech department regarding Octoprint. Now only "home Z" does what you describe; previously "Home X/Y" homed Z as well and did the calibration.
Being an ExPat, I do understand Nigel's humour, but I do not understand why "change is good"; it is much of the time, but in this instance, especially when PR are not releasing compilable source code, changing the meaning of pre-existing standard Marlin commands is just bad.
And yes, G29 has already been pointed out as well. There are sufficient unused Marlin commands to use without re-using existing ones wrongly.
Josef was very upset with Ultimaker and lack of "Open Source"; seems proprietary is the way to go. 😥
To my mind, doing the 9-point check before every print is not necessary. Do it once and store the values. Then nothing has to change. Use probe point one to home Z after X and Y have been homed otherwise use the firmware Z value.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Z motors stays on after M84
That's all swell, but how can I turn off Z motors after print?
Re: Z motors stays on after M84
That's all swell, but how can I turn off Z motors after print?
As far as I know, only by main power switch at the moment.
Re: Z motors stays on after M84
Janis
Did you try the M18 code?
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Z motors stays on after M84
Peter
I'm sorry, I can't do that today, but will test M18 asap and definitely report back.
Re: Z motors stays on after M84
I just tried the M18 from Octoprint, and the Z motor are still locked after it.
I'm like Jon Snow, I know nothing.
Re: Z motors stays on after M84
In that case, then the firmware will need to be amended and recompiled.
Configuration_prusa.h, comment out the line (line 63 in my copy of the source code):
#define Z_AXIS_ALWAYS_ON 1
Janis you need to be aware of some unwanted side-effects:
Stepper motors, when turned off will naturally settle in a full step position. Each full step is 40 microns. When the motors are turned off it is likely that the motors will move up to 20 microns. The motors will turn off after a period of time which will be less than the time it takes to print a single layer on some larger objects.
Therefore, the quality of your prints will suffer.
In addition, you may find it necessary to align the Z axis before the start of each print.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Z motors stays on after M84
Janis you need to be aware of some unwanted side-effects
... or make motor timeout longer. 😉
Re: Z motors stays on after M84
David
OK, give us a clue how to do that then please...
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Z motors stays on after M84
Personally I don't mind to run Z align and any sort of calibration before each print.
Anyway, compared to total print time it's nothing and quality always matters to me.
So, I would love to have in the printer menu setting to specify the type of calibration to perform before every print
- full calibration (then Z align will be enforced and Z motors will be turned off after print job is complete)
- quick calibration, but then Z motors are always on.
I'm sure there will be voices in favor to either choices.
Janis